FAQ for isdn4linux <author>Matthias Hessler (<tt><htmlurl url="mailto:hessler@isdn4linux.de" name="hessler@isdn4linux.de"></tt>) <date>v2.0.97, 11 June 2005 <abstract> If you are reading this FAQ online, you may consider downloading the whole thing, and reading it offline (much cheaper). To download the latest version of this FAQ in TXT/HTML/SGML format, go to the homepage of this FAQ: <url url="http://www.mhessler.de/i4lfaq/">. A German translation of the FAQ is available at: <url url="http://www.wolf-b.de">. This FAQ answers questions that were frequently asked in the newsgroup de.alt.comm.isdn4linux. It contains questions any user should know about ISDN under Linux using isdn4linux, as well as hints on how to best make use of all the features isdn4linux provides. Version 2 of the FAQ is derived from an earlier version which had become outdated at the time of this writing. To obtain information on old versions of isdn4linux (1997 and earlier) please have a look at the FAQ version 1.3.4. About the format of this FAQ: The main basis of this FAQ is the i4l mailing list (see question <ref id="docu_mailinglist" name="docu_mailinglist">). I've treated the knowledge gained from reading as public domain, without quoting the author of the original mail. The FAQ is now written in SGML, as this format is flexible to convert into any other form of documentation (though some restrictions apply). The FAQ is now maintained in English since German-speaking people can easily follow the mailing list/newsgroup (or search in the archives). Whoever wants to translate back to German is welcome to do so! The countless links in this documents are not always complete and I'm sure many are no longer correct. I do not have the time to check them all. If you discover a bad link, please let me know (I'll try to install some automatic checking when I have the time). Additions, improvements and other suggestions are always welcome (also correction of typographical errors!), preferably send "diffs" from the SGML version. Thank you very much in advance! Send feedback about this FAQ to: <tt><htmlurl url="mailto:i4lfaq@isdn4linux.de" name="i4lfaq@isdn4linux.de"></tt> or: <tt><htmlurl url="mailto:hessler@isdn4linux.de" name="hessler@isdn4linux.de"></tt>. The newest version of this FAQ can be found at: <tt><url url="http://www.mhessler.de/i4lfaq/"></tt> or: <tt><url url="http://www.isdn4linux.de/faq/"></tt>. This FAQ is protected by the GNU General Public License (GPL) Version 2; (C) 1999-2002 Matthias Hessler (for version 2.0) Distribution under the terms of the GPL is welcome. However, we offer NO GUARANTEES for the information herein. Please read the GNU General Public License for further details. A printed version is available from Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. An electronic version is available from the author. </abstract> <!-- Table of Content --> <toc> <!-- General Section: About isdn4linux, features --> <sect> general: General information about isdn4linux <label id="general"> <sect1> general_i4l: What is isdn4linux? <label id="general_i4l"> <p> isdn4linux is a set of kernel modules which are part of the Linux kernel. It consists of the main module <tt/isdn/ and the actual hardware driver that control some specific card. In addition, the package <tt/isdn4k-utils/ contains utilities to make use of ISDN specific features. <sect1> general_hardware: What hardware is supported by isdn4linux? <label id="general_hardware"> <p> Generally, isdn4linux can control ISDN cards that are connected to the PC's ISA or PCI bus. Also a few PCMCIA cards are supported. However, isdn4linux can <bf/not/ make use of any devices connected via a serial or parallel interface (which are called 'terminal adaptors'), with only a few exceptions: the Creatix/Teles S0 box for the parallel port, and the Gazel 128 USB. For more details on which cards are supported see section <ref id="hardware" name="hardware">. <sect1> general_features: What features are supported by isdn4linux? <label id="general_features"> <p> Basically, isdn4linux can receive and transmit data via ISDN in several ways (X.75, HDLC, raw ip, synchronous ppp, asynchronous ppp, V.110). Some of its utilities offer additional features. Two examples are <tt/isdnlog/, which allows logging of and reaction to ISDN events (including calculating any charges); and <tt/vbox/, which provides voice answering machine capabilities. For more details see the section <ref id="feature" name="feature">. <sect1> general_countries: Which countries are supported by isdn4linux? <label id="general_countries"> <p> At least all countries which use Euro-ISDN are supported, however some pecularities apply. To find more about your country, check the section <ref id="countries" name="countries">. <sect1> general_docu: Where do I find more documentation, how-to's, helpful tips & tricks? <label id="general_docu"> <p> Besides this FAQ, take a look at the various man pages and Readme's that come with the isdn4linux package. Then there is the isdn4linux website: <url url="http://www.isdn4linux.de">. There is also a mailing list on isdn4linux which will give you the most up to date information. To find out more about these great information sources, see section <ref id="docu" name="docu">. And: check out all the great links listed in question <ref id="config_links" name="config_links">! You may find information in your language, or information specific to your linux distribution. <sect1> general_getlatest: Where do I get the latest version of isdn4linux? <label id="general_getlatest"> <p> The latest version of the kernel drivers should be found in the Linux kernel. However, sometimes the Linux kernel does not have the latest version or does not yet support your ISDN card. Additionally, you may need to use the isdn4k-util package. In those cases you could try to get the very latest version that is currently in development. See the section <ref id="distrib" name="distrib">. <sect1> general_contacts: How can I get in contact with the developers? <label id="general_contacts"> <p> You can contact the isdn4linux developers through the www.isdn4linux.de website. Have a look at <url url="http://www.isdn4linux.de/contacts.shtml">. <!-- Development & Distribution --> <sect> distrib: Distribution <label id="distrib"> <!-- Who are the developers? --> <sect1> distrib_getlatest: How can I get the latest isdn4linux? <label id="distrib_getlatest"> <p> There are different ways, depending on your kernel. Unless you are an experienced user of Linux, you should use a recent kernel (=first option). <itemize> <item>You have a recent kernel (at least 2.0.36/2.2.11/2.3.14): Great choice, you have already the current kernel ISDN stuff. Additionally, you just need to get the current isdn4k-utils package from <url url="ftp://ftp.isdn4linux.de/pub/isdn4linux/utils/"> - unless it's already included in your distribution. <item>You have an older kernel (before 2.0.36/2.2.11/2.3.14): An upgrade to a recent kernel is HIGHLY recommended. And it is MUCH easier to do a kernel upgrade than to get ISDN to work with your older kernel. Ok, now if you still want to keep your old kernel, here is how to do it: First you have to identify the correct CVS extract for your kernel version (CVS is the version control system the ISDN developers use to develop ISDN4LINUX). Take a CVS snapshot that is dated with about the date when your kernel came out. You find the kernel patches and the old isdn4k-utils packages on <url url="ftp://ftp.isdn4linux.de/pub/isdn4linux/"> or on one of its mirrors (see <url url="http://www.isdn4linux.de/download.shtml"> on how to find mirrors). <item>As a developer: If you want to participate in the development of i4l, you can get the very latest stuff via CVS. For this, see the question about access to CVS: <ref id="distrib_cvs" name="distrib_cvs">. </itemize> <sect1> distrib_cvs: How can I access the source from the current development/what is the CVS tree all about? <label id="distrib_cvs"> <p> CVS - Concurrent Version System: This is a multiuser/server extension to RCS (Revision Control System). The I4L drivers are developed under CVS, and there is a server (cvs.isdn4linux.de) with a CVS tree to which all developers have access. In addition, Fritz has configured anonymous read-only access to the CVS tree . If you must have the very latest versions, you can get them there, however they may contain more bugs than the released versions!!! Here is how to get the latest version: <enum> <item>Create and go to the directory where you want to store i4l <code>mkdir ~/cvs; cd ~/cvs cvs -d :pserver:guest@cvs.isdn4linux.de:/i4ldev login</code> <item>Log in (asks for a password, enter <em>readonly</em>) <item>Get the isdn kernel driver stuff (same hierarchy as in the linux source) <code>cvs -d :pserver:guest@cvs.isdn4linux.de:/i4ldev checkout isdn</code> <item>Get the utility package into the current directory <code>cvs -d :pserver:guest@cvs.isdn4linux.de:/i4ldev checkout isdn4k-utils</code> If you want to get the latest version for kernel 2.0.x rather than for the latest kernel, then you have to give the additional option `-r': <code>cvs -d :pserver:guest@cvs.isdn4linux.de:/i4ldev checkout -r isdn4kernel_2_0 isdn</code> <item>After having checked out, further updates can be done by first changing into <tt>isdn</tt> or <tt>isdn4k-utils</tt> subdirectory and running <code>cvs update -P -d</code> Tip: since cvs stores the password on your first login, you don't need to login again when updating. </enum> WARNING!! THE NEWEST STUFF SOMETIMES IS VERY INSTABLE OR MAY NOT EVEN COMPILE WITHOUT PROGRAMMING KNOWLEDGE - No newbie questions on this PLEASE! Use the source, Luke! People who want to <em>continuously</em> help develop isdn4linux by writing new drivers etc. can get a real account for full access. In this case write an email to Fritz Elfert <tt><htmlurl url="mailto:fritz@isdn4linux.de" name="fritz@isdn4linux.de"></tt> <!-- Features --> <sect> Features <label id="feature"> <sect1> feature_not: Which ISDN features cannot be offered by isdn4linux? <label id="feature_not"> <p> Some ISDN features are device-specific and cannot be activated by isdn4linux for other devices, unless isdn4linux were to falsify the TEI (which would probably confuse the other device). Such device-specific ISDN features are, among others: rejection of a waiting call, caller id on/off, hold, conference calls, differing COLP/CLRP. <sect1> feature_data: Which ISDN data transmission modes are supported? <label id="feature_data"> <p> These low-level formats are possible: <itemize> <item> 56k asynchronous : no <item> 64k synchronous : yes <item>128k synchronous : yes (channel bundling - see the question <ref id="feature_2channel" name="feature_2channel">) </itemize> These level2 formats are possible: <itemize> <item>HDLC <item>X.75 <item>transparent <item>V.110 </itemize> These encapsulations are possible: <itemize> <item>rawip <item>ethernet <item>Sync PPP <item>X.25 (requires 2.1 or newer) <item>cisco and cisco-h <item>cisco-hk (=cisco with keepalive; requires 2.1 or newer) <item>plus a few specialities: have a look at the man pages. </itemize> Please note that X.31a is supported as X.25 on top of ISDN, while X.31b is not supported (neither in the B channel, nor in the D channel variation). <sect1> feature_voice: Has isdn4linux voice support (e.g. answering machine, voice-over-ip gateway for H.323 clients)? <label id="feature_voice"> <p> Yes, voice support is included in the current version of isdn4linux. For an answering machine you can either use &dquot;vgetty&dquot; from Gert Doerings &dquot;mgetty+sendfax&dquot;, or &dquot;vboxgetty&dquot; from Michael Herold, which is made especially for isdn4linux. The latter is part of the isdn4k-utils package, which can be found on: <tt><url url="ftp://ftp.isdn4linux.de/pub/"></tt> Also, you can use isdn4linux as a voice-over-ip gateway to let H.323 clients (like Voxilla, Netmeeting) call normal telephones, and/or the other way around. For configuration see question <ref id="config_h323" name="config_h323">. <sect1> feature_fax: Can I fax with isdn4linux? <label id="feature_fax"> <p> <itemize> <item><bf>For passive cards: Yes</bf>. Since 2005 the GPL software ivcall is able to send and receive voice calls and faxes even via passive cards. It makes use of the spandsp library which is part of the Asterisk project. You can find it on: <tt><url url="http://0pointer.de/lennart/projects/ivcall/"></tt> An alternative project working on this problem existed (i4lfax) but has not made any progress since 1999. For more info on its status have a look at: <tt><url url="http://user.cs.tu-berlin.de/~ulfi/osvisions/i4lsoftfax/i4lfax/"></tt> Also, an idea exists to extend the new modular mISDN with layer 2 and layer 3 protocols for fax. Once this works (e.g. with the Sedlbauer Speedfax card) then the layer 1 protocol (modulation/demodulation) could be also be implemented via the spandsp library. <item><bf>For passive cards from AVM: Yes</bf>. AVM recently released a binary CAPI 2.0 driver which supports faxing. However, the setup is rather complicated. Get a start on: <url url="http://www.avm.de/ftp/cardware/fritzcrd/linux/index.htm">. Here is a German website which has some nice installation instructions: <tt><url url="http://ixi.thepenguin.de"></tt> or <tt><url url="http://capi4linux.thepenguin.de"></tt> or <tt><url url="http://www.thepenguin.de"></tt> Please also have a look on the mailing list for tips how to do it, and what the consequences/disadvantages are. <item><bf>For the active card AVM B1: Yes</bf> (its firmware has implemented fax as one of its features). Get the newest stuff from: <tt><url url="ftp://ftp.aeccom.com/pub/fax4i4l/howto/current/"></tt> However, it has been reported that setting it up properly is very tricky. Another site which could be helpful is: <tt><url url="http://www.topf-sicret.de/help/capi20.html"></tt> <item><bf>For the active Hypercope PCI cards HYSDN Ergo2 and HYSDN Metro4: Yes, after upgrade with a special fax card</bf>. The setup is similar to that of an AVM B1, but may require extra patches. <item><bf>For the active Eicon Diva Server cards (except Diva 2.0Pro): Yes</bf>. Have a look at README.fax and README.eicon in the <tt>isdn/Documentation/isdn</tt> directory, as well as: <tt><url url="http://www.melware.de/"></tt>. The Eicon Diva Server cards allow faxing with class 2 commands. <item><bf>For semiactive cards Sedlbauer Speedfax+ and Siemens I-SURF 1.0: Yes</bf> But currently this requires some manual work. Check the mailing list on how to do it (special patch needed). Only class 1 fax commands are supported. You can obtain the patch from: <tt><url url="//ftp.isdn4linux.de/pub/isdn4linux/kernel/v2.2/testing/i4l_isar_fclass1.tar.gz"></tt> The patch is not needed if your kernel is 2.2.15 or later. You have to enable the kernel option for FCLASS2 (CONFIG_ISDN_TTY_FAX=Y). Also, you need to load the firmware of the card (part of the isdn4k-utils) with <code> hisaxctrl <driver_id> 9 ISAR.BIN </code> Then initialize the ttyI* interface with: <code> ATZ&E<your_msn>S0=1S13=1+FCLASS=1 </code> and use a normal Hylafax class 1 config file, where you've replaced non-supported commands (flow control,...) by dummies. For the I-Surf 1.0 also check question <ref id="hardware_isurf" name="hardware_isurf">. </itemize> If you do want to fax now, your best choice is to install an analog fax modem along with your ISDN card. For companies who want to set up a fax server servicing multiple connections you could also have a look at the active ISDN cards. More information for setting up a fax server with hylafax can be found on: on the web site for Hylafax: <url url="http://www.hylafax.org"> or on <url url="http://www.mnd.fh-wiesbaden.de/~dreymann/linux">. <sect1> feature_modem: Can isdn4linux connect to/be called by an analog modem? <label id="feature_modem"> <p> Generally: <bf>NO</bf>. It may only work for cards with which you can fax: see question <ref id="feature_fax" name="feature_fax">. For the Sedlbauer card, you can give the following command on the ttyI*: <code> AT&FS14=10S15=0S18=1&E<your_msn> </code> <sect1> feature_divert: Is it possible to initiate call forwarding with i4l? <label id="feature_divert"> <p> Call diversion features have been implemented recently. Use the new program <tt>divertctrl</tt> in conjunction with the HiSax driver. If you make use of capi4linux, then you find a similar program named <tt>capidivert</tt> at: <url url="http://www.tp1.ruhr-uni-bochum.de/˜kai/i4l/">. For now this is something only for the more experienced user, as so far there is no howto and only little documentation, and it is not automatically included in most distributions. However, it can be used with active ISDN cards. In the Netherlands, the keypad protocol can be used as an alternative. To use it you just dial with the usual dial command from an ttyI device: <code> atd*123*0123456789# </code> <sect1> feature_ipx: Can I route ipx/spx over ISDN with Linux? <label id="feature_ipx"> <p> Yes, set up an ISDN interface with encapsulation <tt/ethernet/, and use IPX framing ETHERNET_II. <em/mars_nwe/ can do the rest (e.g. routing). Also, you can route ipx with ipppd, see question <ref id="syncppp_ipx" name="syncppp_ipx">. To use pppd for ipx, you have to give it the compile option IPX_CHANGE. However, be careful when using dial out on demand (dod), since frequent ipx broadcasts may cause a dod disaster (see question <ref id="dod_disaster" name="dod_disaster">). <sect1> feature_2channel: Does isdn4linux support channel bundling? <label id="feature_2channel"> <p> The current version of isdn4linux support 2 methods of channel bundling: <itemize> <item><bf>MPPP</bf> (based on sync PPP) <item><bf>Raw bundling</bf> (configured by so-called slave channels) </itemize> Both variants have their own advantages and disadvantages. See section <ref id="2channel" name="2channel">. Bonding (16bit channel) is not supported, since it can not work reliably when the dialup connections have deviating latency. Warning: Channel bundling saves time, but not telephone charges. It is useful only if you really need the extra bandwidth. <sect1> feature_diald: Can I combine isdn4linux with diald? <label id="feature_diald"> <p> Yes, you can. You have to configure it to use the ttyI* devices to dial out. E.g. like this: <code> /usr/sbin/diald /dev/ttyI4 -m ppp [...] </code> where [...] stands for further dialout parameters. The recent diald releases contain configuration files for ISDN. See <url url="http://diald.sourceforge.net"> for details. <sect1> feature_dod: Does the driver support &dquot;dial on demand&dquot;? <label id="feature_dod"> <p> Yes. If a network interface (e.g. &dquot;isdn0&dquot;) is set up, the driver will dial the number. If in addition a hangup timeout (Idle Timeout) has been given (like: <tt>isdnctrl huptime <interface> <time></tt>), then the driver will automatically hang up when no data was been transferred over the interface for >time< seconds. However, with syncPPP there are problems (see the syncPPP section). Also look at the dialmode description (see question <ref id="dialout_dialmode" name="dialout_dialmode">). You should definitely be very interested in the large section of this FAQ that talks about the dangers of unwanted dialouts: (<ref id="dod" name="dod">). <sect1> feature_sms: Can I send SMS (short messages) to my mobile phone via ISDN? <label id="feature_sms"> <p> Yes, you can use the program <tt/yaps/ to do this. However, due to some pecularities in the SMS-callcenter's ISDN connection, you have to compile the kernel with the options <tt/Disable send complete/ and <tt/Disable sending llc/. Please note that mainly German providers support sending SMS via ISDN connection, in other countries this might not work. Dutch as well as UK SMS callcenters seem to not support this feature. Please let me know if you have additional information on this. A useful sample config for yaps you might find on: <url url="http://www.tnt-computer.de/linux/yaps-suite1-1.tgz"> Another program to send SMS is <tt>asterisk</tt>. Have a look at: <url url="http://www.asterisk.org"> and <url url="http://www.voip-info.org/wiki-Asterisk+cmd+Sms">. One advantage over yaps is that it can also receive SMS, for Germany (you have to register for this first by sending a specific SMS - otherwise the SMS will be communicated to you by an automated voice call). Yet another program to send SMS is <tt>smsclient</tt>. You can find it on: <url url="http://www.smsclient.org">. <sect1> feature_btx: Is the German videotex/Btx/Datex-J possible with isdn4linux? <label id="feature_btx"> <p> Yes, it works with the modem emulation with the ttyI* devices. There is a special register to set for videotex (ATSx=y - see the Readme's) Warning! XCept (formerly Xbtx) has an ISDN configuration option. This should NOT be used. XCept should be configured as if a normal modem were being used. <sect1> feature_clock: Can I set the clock of my computer with ISDN? <label id="feature_clock"> <p> Yes. Isdnlog offers this feature with option &dquot;-t&dquot;. Unfortunately, the seconds are not transmitted via ISDN, and the transmitted time is not very accurate - depending on the ISDN equipment of your telephone company there may be a deviation of several minutes (!). It's better to get a PC clock that is set by radio signals and check it with, for example, xntp. You can also use a time server in the Internet with &dquot;netdate&dquot; or &dquot;rdate&dquot;. Check out the following urls on information about using time servers: <itemize> <item> <url url="http://www.eecis.udel.edu/~mills/ntp/servers.html"> <item> In German: <url url="http://www.ptb.de/deutsch/org/4/43/433/verb.htm"> <item> In German: <url url="http://www.ptb.de/deutsch/aktuell/pi/pi00/pi0100.htm"> </itemize> <sect1> feature_dosemu: Can I use isdn4linux under dosemu? <label id="feature_dosemu"> <p> Yes, you can! Steffan Henke <tt><htmlurl url="mailto:henker@informatik.uni-bremen.de" name="henker@informatik.uni-bremen.de"></tt> wrote on 25 Oct 96: <quote> In dosemu.conf it is enough to enter a virtual com port, (for example com2) that can be used with e.g. Telix or Terminate: serial { com 2 device /dev/ttyI3 } Access with Fossil is possible if fossil.com (included with dosemu) is started. Tested with the following configurations: - Kernel 2.0.21, Teles driver incl. Karsten's patches - Kernel 2.0.21, HiSax </quote> <sect1> feature_capi: Is there a CAPI interface available? <label id="feature_capi"> <p> Currently, these cards support the CAPI 2.0 interface: <itemize> <item> the active card AVM B1. <item> the active DIVA Server cards from Eicon. <item> the active cards from Hypercope (HYSDN Champ2, HYSDN Ergo2, HYSDN Metro4) <item> the passive Fritz card from AVM. However, please note that you have to download and manually install the binary drivers for this from AVMs ftp server. See the following web site for a nice howto: <url url="http://www.topf-sicret.de/help/capi20.html">. There was also lots of stuff written in the mailing list on this. Here is a German website which has some nice installation instructions: <tt><url url="http://ixi.thepenguin.de"></tt> or <tt><url url="http://capi4linux.thepenguin.de"></tt> or <tt><url url="http://www.thepenguin.de"></tt> Please note that due to its binary nature, this driver will not work if your distribution is incompatible with it (e.g. based on 64 bit). </itemize> This interface follows the official CAPI 2.0 standard that was established recently for Linux by the CAPI Association (see <url url="http://www.capi.org">). Since kernel 2.6.0 the CAPI interface has been used as the general interface, also for other cards. For passive cards, the new driver mISDN will replace the old hisax driver once it is fully functional. There are no plans to implement a CAPI 1.1 interface. <sect1> feature_uus: Is UUS (user to user signaling) supported? <label id="feature_uus"> <p> Yes, isdn4linux could support both sending and receiving, but the implementation is currently rather incomplete due to the unclear legal situation for using this facility. Receiving UUS is only possible through the debug interfaces. Sending is supported in connection with the diversion services (when rejecting a call or announcing a busy condition), but not on an ordinary call. It is recommended to use subaddressing (see question <ref id="feature_subaddressing" name="feature_subaddressing">) instead. Please note that sending UUS it is not a free service (receiving is free), at least with some German phone providers you have to pay extra for it (also have a close look on the usage conditions). Additionally, please note that if you are connected through a PBX, it may filter out all the UUS stuff. <sect1> feature_subaddressing: Is subaddressing supported? <label id="feature_subaddressing"> <p> Yes, isdn4linux does support subaddressing (available in France). To configure it, give HiSax the number in this format: <tt><number>.<subaddress></tt>. However, you may have to order it seperately and pay extra for receiving it (sending is free), depeding on your ISDN provider. Additionally, please note that if you are connected through a PBX, it will most likely filter out all the subaddressing stuff. <sect1> feature_gsmv110: Can I connect from my PDA via GMS cellular phone to isdn4linux? <label id="feature_gsmv110"> <p> Yes, if the provider of the cellular phone has a GSM to ISDN/V.110 gateway. This has been reported to work from a PalmPilot to isdn4linux with V.110. See question <ref id="config_gsmv110" name="config_gsmv110"> for details on how to configure it. <sect1> feature_reversedcard: Can isdn4linux log ALL actions happening on the ISDN bus (dual mode/reversed card/COLP/...)? <label id="feature_reversedcard"> <p> Yes, isdn4linux offers several possibilities to do this. Have a look at question <ref id="isdnlog_reversedcard" name="isdnlog_reversedcard">. Please note that you may also use the software ISDN Sniffer for this, see the German web site <url url="http://krypt.cs.uni-sb.de/projects/isdnsniffer/">. <sect1> feature_chargeint: Can isdn4linux hang up just before the ISDN provider would charge me for another unit? <label id="feature_chargeint"> <p> Yes, isdn4linux can do this. Check out section <ref id="chargeint" name="chargeint">. <sect1> feature_eurofile: Can isdn4linux download or offer files via EFT (Eurofile transfer)? <label id="feature_eurofile"> <p> Yes, isdn4linux offers special tools for this which are part of the isdn4k-utils. <sect1> feature_leased: Can isdn4linux handle leased lines (e.g. D64S)? <label id="feature_leased"> <p> Yes, isdn4linux can handle leased lines (explained in the glossary: <ref id="glossary_leased" name="glossary_leased">). Have a look at section <ref id="leased" name="leased">. <sect1> feature_pointtopoint: Can isdn4linux work in point-to-point mode as well as in multi-device mode? <label id="feature_pointtopoint"> <p> Yes, isdn4linux supports both. Check the glossary to understand the difference: <ref id="glossary_pointtopointmode" name="glossary_pointtopointmode"> and <ref id="glossary_multidevicemode" name="glossary_multidevicemode">. <sect1> feature_ntmode: Does isdn4linux support running a card in NT mode? <label id="feature_ntmode"> <p> Yes, isdn4linux does support it, but only for a few special cards. See question <ref id="feature_crossedcable" name="feature_crossedcable"> for details. In the glossary there is more information on what the NT mode is: <ref id="glossary_ntmode" name="glossary_ntmode">. <sect1> feature_crossedcable: Can isdn4linux directly connect two ISDN user devices (two ISDN cards) via a crossed cable? <label id="feature_crossedcable"> <p> Yes, isdn4linux can do this. However, this requires that the ISDN card can run in NT mode (for details on this mode see the glossary: <ref id="glossary_ntmode" name="glossary_ntmode">). Only very few cards (e.g. HFC chipset) are cable of doing this. Use the following command to start the ISDN card in NT mode: <code> hisaxctrl <id> 98 1 </code> Make sure that the crossed cable is terminated even if it is very short! Nothing will work without termination, not even a 1m cable. Some HFC card already have jumpers for termination. However, this will only give you the physical connection. Up to now isdn4linux does not (yet?) implement the higher level ISDN protocol DSS1 (this means that isdn4linux can not pretend to an ISDN device that it is an ISDN exchange, and give it the proper ISDN commands). As a result, you can simulate a leased line, but not pretend to be the PBX. <sect1> feature_lcr: Can isdn4linux do least cost routing (LCR)? <label id="feature_lcr"> <p> Yes, this feature is now being supported by isdnlog. What it does is that it allows isdnlog to choose your telephone provider when placing a call through your ISDN card, depending on the time of day and the current rate information. Since isdnlog 4.16 an external script is called (if configured) to change various ISP settings (e.g. DNS lookup, proxy setup,...). Note: the ABC-extensions (s. <ref id="docu_abc" name="docu_abc">) must be installed. Also, isdnlog should always be running (otherwise your dialout will be delayed by 3 seconds). If the ABC-extensions are not installed, isdnlog prints hints to the log file, which provider would have been chosen. <sect1> feature_internetdialin: Can isdn4linux be setup such that it dials into the Internet, whenever I call it via telephone? <label id="feature_internetdialin"> <p> Yes, this is possible with isdnlog. You have to configure isdnlog such that it can execute a script whenever someone dials in. In the script you can check for the correct telephone number, then trigger the dialin. To access your computer then over the internet, you can then access it via its ip address. In case of dynamic ip address assignment, you probably want to store the new ip somehow. Storage in a html page or via dynamic DNS may be good possibilities. If you understand German, there was an article about exactly this setup in ct 18/2002, page 204 (Bei Anruf Internet - Handy-Anruf löst Internet-Einwahl aus). Also, the following German web site explains how to set up such a configuration: <tt><url url="http://www.staschke.de/linux/anwahl.html"></tt> <sect1> feature_future: Which features are planned for the future? <label id="feature_future"> <p> Actually, most features have been implemented and are now being improved. But, who knows what other interesting stuff the developers may come up. We'll see... <!-- Helpful docu, links, mailing list, config examples, howto's --> <sect> docu: Documentation, Howto's, Tips & Tricks, Mailing List/Newsgroup <label id="docu"> <sect1> docu_first: What documents should I read first? <label id="docu_first"> <p> <itemize> <item>ISDN kernel subsystem: /usr/src/linux/Documentation/isdn/README <item>ISDN cards: /usr/src/linux/Documentation/isdn/README.card E.g.: /usr/src/linux/Documentation/isdn/README.HiSax <item>Synchronous PPP: /usr/src/linux/Documentation/isdn/README.syncppp /usr/src/linux/Documentation/isdn/README.syncPPP.FAQ <item>Voice capability: /usr/src/linux/Documentation/isdn/README.audio <item>ISDN Utilities: /usr/src/isdn4k-utils-version/README(.*) </itemize> Many of the utilities also have man pages! To get a good technical overview over isdn4linux have a look at the great whitepaper 'ISDN4Linux, CAPI4Linux, CPI4Hisax and other cute acronyms: The ISDN subsystem in the Linux kernel', which can be found at: <tt><url url="http://www.linux-kongress.org/2002/papers/lk2002-germaschewski.pdf"></tt> For a Suse distribution the following information might be helpful: <itemize> <item><tt>/usr/doc/packages/i4l*</tt> (for i4l in general) <item><tt>/usr/doc/faq/faq/PPP-FAQ</tt> (for synchronous PPP) <item><tt>/usr/doc/howto/mini/Mail-Queue.gz</tt> (for email configuration) </itemize> Also, read the excellent manual! For a Debian distribution the following information might be helpful: <tt>/usr/share/doc/isdnutils/HOWTO.gz</tt> If you are reader of the German computer magazine <tt/ct/, they had very helpful articles at least on these issues: <itemize> <item>ct 5/1998, page 224: <tt>Der erste Kontakt/Linux: Mit PPP ans Internet</tt> <item>ct 21/1998, page 288: <tt>Reiseleiter/Internet-Anbindung für das LAN</tt> <item>ct 25/1998, page 218: <tt>Bei Anruf Netz/Linux: Dial-In Server</tt> <item>ct 7/2001, page 228: <tt>Des Surfers Bastelstunde: Mobilfunktechnik HSCSD ausschöpfen</tt> (also contains information on dial-in configuration without HSCSD). <item>ct 15/2002, page 204: <tt>Bei Anruf Internet: Handy-Anruf löst Internet-Einwahl aus</tt> <item>ct 3/2004, page 182: <tt>Heimserver im Eigenbau - Teil 4: ISDN-Grundlagen für Linux</tt>(also contains information about the new mISDN driver). An online version is available on: <tt><url url="http://www.heise.de/ct/04/03/182/"></tt> <item>ct 9/2004, page 100: <tt>Tux vermittelt - Linux als Telefonanlage mit VoIP</tt>(refers to software PBX4Linux) </itemize> Also have a look at question <ref id="config_links" name="config_links"> for helpful links on how to configure i4l (e.g. special help for SuSE, Red Hat, or Mandrake users). <sect1> docu_website: Where is the official website for isdn4linux? <label id="docu_website"> <p> The offical website can be found at: <url url="http://www.isdn4linux.de">. <sect1> docu_abc: Where do I find documentation on the abc extensions? <label id="docu_abc"> <p> You can find it on: <url url="http://i4l.mediatronix.de/"> <sect1> docu_newsgroup: Where is the newsgroup for isdn4linux? <label id="docu_newsgroup"> <p> The newsgroup was <tt>de.alt.comm.isdn4linux</tt>, however had been closed down some time ago due to spam issues. To get in contact with the developers your best choice is to use the mailing list <ref id="docu_mailinglist" name="docu_mailinglist">. Alternatively, you find some interesting stuff in <tt>de.comp.os.unix.linux.isdn</tt>. <sect1> docu_mailinglist: Where is the mailing list for isdn4linux? <label id="docu_mailinglist"> <p> The address of the mailing list is <tt>isdn4linux@listserv.isdn4linux.de</tt>. Before posting a message there please make sure it is not answered in this FAQ, and that the question has not been answered numerous times in the past (search <url url="http://www.deja.com/"> with keywords like ISDN, Linux, i4l, isdn4linux,...). People on the mailing list get really annoyed when the question "can I fax with my card xxx" is asked yet another time (see question <ref id="feature_fax" name="feature_fax"> for the answer). To reduce spam, as of 25. Aug. 2003 the mailing list has been changed to permit posts from subscribed members only. To write, you must be subscribed first. When writing on the mailing list, please always provide: <itemize> <item> Your Kernel version <item> Your i4l/hisax version <item> Your card type </itemize> Most isdn4linux developers are present on the mailing list, and many other knowledgeable people. <bf>English postings are very welcome, and will be answered in English!</bf> The mailing list contains the same messages as the newsgroup (see question <ref id="docu_newsgroup" name="docu_newsgroup">), so you can read any responses to your question with your news reader. A bidirectional gateway ensures that mailing list and news are in sync. To subscribe to the mailing list, go to the web frontend at <tt><htmlurl url="https://www.isdn4linux.de/mailman/listinfo/isdn4linux" name="https://www.isdn4linux.de/mailman/listinfo/isdn4linux"></tt> and submit the filled form. After that, you will <bf>not</bf> be subscribed yet. Instead, you will receive a confirmation at the mail address you entered in the above form. This is a security precaution to prevent subscription by other persons or subscription of mistyped mail addresses. When you receive the confirmation, just follow the instructions in that mail. (I.e.: simply reply). After having replied, you will be subscribed and receive a welcome mail. The welcome mail will contain your password, so you should probably keep it just in case you want to unsubscribe or change some options at the web frontend. To unsubscribe, go to the web frontend again, use your password to login and then unsubscribe. Please note: there are about 20-50 messages per day on this mailing list. To receive only one message per day, containing all postings, have a look at question <ref id="docu_maillistdigest" name="docu_maillistdigest">. <sect1> docu_maillistdigest: How can I get a digest of the mailing list for isdn4linux (only one message per day)? <label id="docu_maillistdigest"> <p> While filling the form as described in question <ref id="docu_mailinglist" name="docu_mailinglist">, simply click "Yes" at the radio-button, named "Would you like to receive list mail batched in a daily digest". You can change this option later when logging in the web frontend. <sect1> docu_mailarchive: Is there an archive of the isdn4linux mailing list? <label id="docu_mailarchive"> <p> To quickly search for keywords, you can use <tt><url url="http://www.deja.com"></tt>. Make sure to also select older archive to do a complete search. Messages are also saved (unsorted) at listserv.isdn4linux.de, collected by month. To access the archive, you can use <url url="http://www.isdn4linux.de/listarch/">. Other archives are: <itemize> <item><tt><url url="ftp://ftp.uni-oldenburg.de/pub/unix/linux/isdn/isdn4linux/Mailing-List"></tt> </itemize> <!-- Supported Hardware & hardware-specific stuff --> <sect> hardware: Supported hardware, its specialities, and hardware-related problems <label id="hardware"> <sect1> hardware_support: Which hardware is supported? <label id="hardware_support"> <p> Only internal cards that plug into an ISA or PCI slot are supported. ISA Plug&Play cards are also supported, but need some additional manual configuration by means of the <tt/isapnptools/. For details on the configuration see question <ref id="config_pnp" name="config_pnp">. Internal cards may be <ref id="glossary_active" name="active">, <ref id="glossary_semiactive" name="semi-active">, or <ref id="glossary_passive" name="passive">. Unless you have paid big money, assume you have a passive card. More about the difference: see question <ref id="hardware_activepassive" name="hardware_activepassive">. Right now there is a driver for all passive card with certain Siemens chipsets (HiSax driver). Have a look at the <tt>README.HiSax</tt> that comes with the driver for the most up to date information on supported cards and which parameter to pass to Hisax. Here the status from 1st February 2002 (constantly improving): <itemize> <item>Teles 8.0/16.0/16.3 and compatible ones (like: Dr. Neuhaus Niccy 1016, Creatix 16/S0) <item>Teles 16.3c (can not be used as reversed card) <item>Teles S0/PCMCIA (old hardware) <item>Teles PCI <item>Teles S0Box <item>Creatix S0Box <item>Creatix PnP S0 <item>Compaq ISDN S0 ISA card <item>AVM A1 (Fritz, Teledat 150 ISA) <item>AVM Fritz PCMCIA <item>AVM Fritz PnP <item>AVM Fritz PCI (Teledat 150 PCI) <item>AVM Fritz PCI v2 <item>ELSA Microlink PCC-16, PCF, PCF-Pro, PCC-8 <item>ELSA Quickstep 1000 <item>ELSA Quickstep 1000PCI (new name: ELSA Microlink PCI) <item>ELSA Quickstep 3000 (same settings as QS1000) <item>ELSA Quickstep 3000PCI <item>ELSA PCMCIA <item>ITK ix1-micro Rev.2 (also: ITK colombus card) <item>Eicon DIVA 2.0 ISA and PCI (S0 and U interface, no PRO version) <item>Eicon.Diehl Diva 2.01 ISA and PCI, and Diva 2.02 <item>Eicon DIVA Piccola <item>ASUSCOM NETWORK INC. ISDNLink 128K PC adapter (order code I-IN100-ST-D) <item>Dynalink IS64PH (OEM version of ASUSCOM NETWORK INC. ISDNLink 128K adapter) <item>All other ASUSCOM/Dynalink cards (includes OEM versions; in total more than 50 card versions) <item>PCBIT-DP (OEM version of ASUSCOM NETWORK INC. ISDNLink) <item>HFC-2BS0 based cards (TeleInt SA1) <item>Sedlbauer Speed Card (Speed Win, Teledat 100, PCI, Fax+) <item>Sedlbauer Speed Star/Speed Star2 (PCMCIA) <item>Sedlbauer ISDN-Controller PC/104 <item>USR Sportster internal TA (compatible Stollmann tina-pp V3) <item>ith Kommunikationstechnik GmbH MIC 16 ISA card <item>Traverse Technologie NETjet PCI S0 card and NETspider U card <item>Dr. Neuhaus Niccy PnP/PCI <item>Siemens I-Surf 1.x (with ISAR =< try type 29) <item>Siemens I-Surf 2.x (with IPAC => try type 12 asuscom) <item>Trust PCI (only the old one with Siemens chip; the one called 'Wisecom' in NL does not work) <item>ACER P10 <item>HSR Saphir <item>Berkom Telekom A4T <item>Scitel Quadro <item>Gazel ISDN cards <item>HFC-PCI based cards <item>PCI/Winbond W6692 based cards <item>HFC-S+, HFC-SP/PCMCIA cards <item>HFC-USB ISDN TAs <item>ST5481 based USB ISDN adapters, e.g. BeWan Gazel 128 USB </itemize> Note: <itemize> <item>AVM A1+ is not supported <item>PCF, PCF-Pro: up to now, only the ISDN part is supported <item>PCC-8: not tested yet <item>Eicon Diva U interface not tested <item>Some cards do not work when compiled into the kernel, only when loaded as modules. <item>Asuscom card: please note that the ISA version is a different type (12) then the PCI version (35 for HFC chip or 36 for Winbond chip)! <item>To distinguish between HFC-PCI and PCI/Winbond, have a look at the output of <tt>cat /proc/pci</tt>. You have HFC-PCI if you have a line saying "Master capable" for your card. <item>DataFire Micro V PCI = HFC-based card (type 35) <item>Xircom Cardbus Eth10/100+ (PCMCIA) is not supported by isdn4linux, but you can use it like an active external ISDN terminal adapter (requires the xircom and serial driver). <item>Gazel 128 USB from BeWAN Systems is supported as hisax_st5481 module. For configuration hints have a look at: <url url="http://www.posern.org/my-prjs/isdn/">. </itemize> In Germany: every ISDN card which German Telekom distributed in the past is supported (the same is NOT true for the PBX they distributed). The following cards are definitely not supported and will probably never be supported, since the manufacturers have not released the specifications for their very proprietary hardware/protocols: <itemize> <item>Fritz!X <item>Eumex 404 </itemize> As for the Eumex 404, there is an unofficial binary driver for isdn4linux with Suse 6.3, which may or may not help you. Use it at your own risk: <url url="http://home.t-online.de/home/MetalMilitia/eumex.htm"> <sect1> hardware_activepassive: What is the difference between an active and a passive ISDN card? <label id="hardware_activepassive"> <p> An active ISDN card handles most of the ISDN connection protocols (dialing, accepting calls, etc.) itself. The card includes a kind of minicomputer with its own software (firmware). With a passive card, the computer in which the card is installed has to perform these functions. In principle, both types are supported by isdn4linux. However, since active cards have non-standard interfaces, a driver can only be made when the producer publishes the specifications for the interface. Also, the card's firmware needs to be made freely available. In contrast, many passive cards share the same chipset. Therefore many passive cards can be supported once a driver supports this one chipset. These active cards are currently supported by an individual driver: <itemize> <item>AVM B1 <item>AVM C4 <item>Eicon DIVA Server BRI PCI <item>Eicon DIVA Server 4BRI <item>IBM Active 2000 ISDN card <item>ICN <item>PCBIT-D </itemize> <sect1> hardware_recommend: Which card is recommended by the developers? <label id="hardware_recommend"> <p> The developers suggest using ELSA cards. ELSA has made their specifications available to the developers, and provided a lot of support, resulting in an excellent driver. Also, their cards are certified for usage in Germany, see question <ref id="country_certified" name="country_certified">. If you want to buy an active card, then the developers would recommend the PCI Server from Eicon. The reason is that it can fax on both channels with AT class 2 commands, and includes a V.90 modem. The AVM B1 works also very well, and is likewise recommended. Old versions (up to 3.0) could receive faxes only on one channel, but since AVM B1 PCI V4 all channels can be used simulateously for sending and receiving faxes. See also question <ref id="hardware_avmb1" name="hardware_avmb1"> for more details about this card. The Hypercope cards have also been reported to work very well, servicing all available channels for faxing. However, they require a hardware update for faxing and their linux driver is fairly new. See also question <ref id="hardware_hypercope" name="hardware_hypercope"> for more details about this card. If faxing is important for you, but you don't want to spent the money for an active card, then a card with ISAR chipset may work well for you, e.g. Sedlbauer Speedfax+ (in Germany you may be able to buy it at Conrads). And if you want to buy a USB terminal adapter, then the Gazel 128 USB from BeWAN Systems <url url="http://www.bewan.com"> has been reported to work fine with the hisax_st5481 module. <sect1> hardware_external: Does isdn4linux support external terminal adapters? <label id="hardware_external"> <p> Generally not, but it doesn't need to. Terminal adapters are designed to behave either like a modem or like a network card. Linux already supports both modems and network cards without isdn4linux - so no special ISDN driver is necessary (which usually greatly simplifies the configuration). For example, have a look at the dialout program wvdial. However, there is (at least) one exception. The Gazel 128 USB from BeWAN System in France <url url="http://www.bewan.com"> has been reported to work fine with the hisax_st5481 module. For configuration hints have a look at: <url url="http://www.posern.org/my-prjs/isdn/">. <sect1> hardware_cabeling: How should I wire my ISDN cables? <label id="hardware_cabeling"> <p> For any details in this direction have a look at the excellent cable FAQ, which can be found at least in a German version at: <url url="http://www.in-berlin.de/User/scorpio/faqkabel.html">. <sect1> hardware_irq: Why should I avoid IRQ 12 and 15 for my ISDN card? <label id="hardware_irq"> <p> On many PCI boards, interrupt 12 is often used by a PS/2 mouse (even though you may not have any or the IRQ is not activated for it). It may be used even when you have no PS/2 port. Interrupt 15 is also often used by the second IDE bus (even when you are not using it or the IRQ is not activated for it). Even though one thinks that some IRQs are available they are still somehow reserved by the BIOS. Good IRQs to try are always IRQ 5 and IRQ 9. Without mice or modems you could also try 4 and 3, which works even on very exotic boards. <sect1> hardware_irqsharing: Can the isdn4linux driver work with shared interrupts? <label id="hardware_irqsharing"> <p> Yes, the drivers have been written to work with shared interrupts. However, at least for the AVM Fritz!PCI card occasional problems have been reported for motherboards with a BIOS bug (DFI motherboards K6BV3+, P5BV3+ K6XV3). Try to disable the BIOS option <tt>CPU to PCI WRITE Buffer</tt> in those cases as a workaround. <sect1> hardware_s2m: Which S2M cards are supported? <label id="hardware_s2m"> <p> At least these S2M cards have been reported to work: <itemize> <item>AVM T1 <item>Eicon S2M-ISA or DIVA Server PRI family (see <url url="http://www.melware.de/">) </itemize> <sect1> hardware_pcmcia: Which PCMCIA cards are supported? <label id="hardware_pcmcia"> <p> At least these PCMCIA cards have been reported to work: <itemize> <item>ELSA Microlink (NOT: ELSA Microlink/all) <item>Sedlbauer <item>AVM <item>Teles PCMCIA (old hardware) - deprecated, since Teles often changes hardware, and does not support the developers (see question <ref id="hardware_teles" name="hardware_teles">). </itemize> <sect1> hardware_smp: Can I run isdn4linux on my multi-CPU board? <label id="hardware_smp"> <p> Yes, this works nicely. However, make sure to compile the kernel and all modules with option <tt/SMP/. If you run into problems when both CPUs try to handle the same IRQ, try to boot with <tt/noapic/. <sect1> hardware_64bit: Can I run isdn4linux on 64bit hardware with Linux? <label id="hardware_64bit"> <p> In principle yes, however your hardware choice is currently limited to active cards and external devices. Most desired are external devices using standard interfaces (network, USB) which do not require isdn4linux at all. The drivers for passive cards are currently not working under 64bit. Obviously you can also not make use of binary drivers, unless you find a binary compiled for 64bit. One external USB device based on the HFC-S chipset reported to work with isdn4linux is the Sitecom DC 104 with serial number greater than SN 46000202 (olders are ST chipset based, they have the same box). Also "tiny USB TA" from Billion, and "surf mini usb" from Acer have been reported to work. <sect1> hardware_alpha: Can I run isdn4linux on a DEC Alpha with Linux? <label id="hardware_alpha"> <p> Yes, most cards should run with isdn4linux on a DEC Alpha. Many cards have been reported to work with the HiSax driver. Also the active ICN card has been reported to work. <sect1> hardware_sun: Can I run isdn4linux on a Sun workstation? <label id="hardware_sun"> <p> Probably not. There are three options for (internal) isdn in the SUN enviroment: <enum> <item> SBUS ISDN adapter: Old SUN-workstations used to have a SBUS interface for additional peripheral boards. There exists an ISDN sbus board sold as "X1012". As no information is available for these boards, they are NOT supported! <item> Built-in ISDN adapter: Sparc-Station-LX, Sparc-Station-10 and Sparc-Server-10 have a motherboard with build-in isdn-adapter. These machines were supported by HISAX (kernel 2.3.0) but the code has been left unsupported for very long (over nine months). All kinds of ancient hisax definitions are still left in these drivers. Much work is to be done to get it properly working again. Note from the original developer, not to expect too much: the dbri chip is not capable of buffering (irq for each byte) and raw-hdlc has to be done in software instead of hardware... The author of dbri.c has stopped active work on it, but made a copy of the DBRI data sheet available at: <url url="http://www.freesoft.org/Linux/DBRI"> for anyone who wants to fix the remaining glitches (status as of Jan 10, 2000). Please be aware that the code of the latest developments can not be compiled for 32 bit machines like all sun-4m machines. <item> PCI ISDN adapter: Modern SUN-workstations and servers have a different busstructure nowadays. The ULTRA series uses the PCI-bus. Allthough some pc boards seem to be working in a SUN, there are NO reports (yet) of properly functioning ISDN-PCI-boards in the SUN environment. Please write me if anyone ever succeeds. </enum> <sect1> hardware_ppc: Can I run isdn4linux on a PowerPC with Linux? <label id="hardware_ppc"> <p> Yes, most cards should work. However, at least the AVMFritz!PCI card won't work, due to the different Endian format for 32bit B-channel data on the PPC. In any case, you may also get a terminal adapter (= external ISDN "modem"). Since then you don't need isdn4linux (see question <ref id="hardware_external" name="hardware_external">), this is not covered here any further. <sect1> hardware_maxcards: How many ISDN cards can I put into my computer? <label id="hardware_maxcards"> <p> It depends on the availability of slots, interrupts/IO addresses in your computer as well as the possibilities of the ISDN card. Most passive cards are limited by the supported IO addresses (e.g.: Teles 16.x: only 3 addresses are legally possible: 0xf80, 0xd80, 0xe80), and the total usage of interrupts (every card needs one). To use more cards, the ICN card may be your choice. It has no interrupts, a more flexible port configuration and the driver places the shared memory area of all ICN cards at the same address. The card memory is shown only as needed. Therefore, one can use as many cards are there are slots. If you really need a lot of ports, then eventuelly, a S2M card might be interesting for you, see question <ref id="hardware_s2m" name="hardware_s2m">. See question <ref id="config_manycards" name="config_manycards"> about the specialities for the configuration of more than one card. <sect1> hardware_hfc: What is special about card with an HFC chip? <label id="hardware_hfc"> <p> Cards with an HFC-PCI chip allow some specialities that are not possible with other ISDN cards. So it is possible to run the card in NT mode (requires crossing the ISDN connection and change by software) - this means you can simulate to another ISDN card that your card is an NTBA. Since isdn4linux does not implement the level 3 protocol used by the exchange, you can only use this mode like a leased line. However, some special software named PBX4Linux has been written for this. You may want to have a look at the German article in ct 9/2004 on how to use PBX4Linux. You can also check the web site <tt><url url="http://isdn.jolly.de"></tt>. You may especially be interested in the information about card support for the NT mode with mISDN at: <tt><url url="http://isdn.jolly.de/cards.html"></tt>. Another alternative for emulation of a PBX is Asterisk, to be found on: <tt><url url="http://www.asterisk.org"></tt>. Also, it is possible to give up one B-channel in exchange for reading the complete D-channel protocol, which is great for isdnlog. The later can also be done with a reversed card (see question <ref id="isdnlog_reversedcard" name="isdnlog_reversedcard">) but with HFC chips this works much more reliably and cleanly. You can activate this special echo mode by calling: <code> hisaxctrl <driver_name> 10 1 hisaxctrl <driver_name> 12 1 </code> You can deactivate it by calling: <code> hisaxctrl <driver_name> 12 0 hisaxctrl <driver_name> 10 2 </code> Parameter 10 changes the number of available channels, parameter 12 switches the echo mode. Cards with HFC chips may be difficult to run on older mainboards. Ensure with <tt>lspci -v</tt> that an IRQ has been assigned to the card (if not check the PnP bios settings). Verify that the card is located in a slot with busmaster DMA capabilities. Verify whether the kernel is compiled such that it will run on your CPU (newer distributions may not run on CPUs like 486 or Pentium; Suse provides the kernel 'k_i386' to run with older hardware). <sect1> hardware_elsa: What should I know about ISDN cards from ELSA? <label id="hardware_elsa"> <p> Generally, ELSA supports the ISDN4LINUX developers quite well with documentation on how to access their cards. Thus, these cards are well supported and very recommendable for use under ISDN4LINUX. Also, the ELSA Quickstep 1000 PCI (new name Microlink PCI) is one of the only brands of cards that are officially certified for use in Germany, and therefore in EC (see question <ref id="country_certified" name="country_certified"> for more information on certification). However, there is a speciality with some non-PCI-conformal mainboards and the ELSA Quickstep 1000pro-PCI. These mainboards set the IO address to incorrect values (they need to be on 0x100 boundaries, and in a higher area). This may create an error message like "You may have the wrong PCI bios" and hang the system. The best fix is a Bios upgrade. If this is not feasible, you can get the module <tt/pcitest/ from Karsten Keil <tt><htmlurl url="mailto:keil@isdn4linux.de" name="keil@isdn4linux.de"></tt>. It will initialize the card correctly, then exit with an intentional error (thus not occupying any memory). To interface from ELSA's RJ11 plug to an RJ45 cable, use the following cabling scheme: <verb> RJ11 - RJ45 pins 1234 12345678 Cable abcd --abcd-- </verb> Regarding the Elsa Microlink ISDN USB: contrary to previous announcements it does NOT works like a serial terminal adapter with the USB communication class driver. Currently, it is not supported by isdn4linux. <sect1> hardware_sedlbauer: What is special about the Sedlbauer card? <label id="hardware_sedlbauer"> <p> The Sedlbauer card comes in several versions: <itemize> <item> Sedlbauer Speedwin <item> Sedlbauer Speedfax <item> Sedlbauer Speedfax PCI </itemize> The Speedwin is a normal passive card with no specialities. The Speedfax has a very special hardware: it is a semiactive card based on the ISAR chipset which supports sending/receiving faxes and an analog modem up to 14400. It is special in that you use it with HiSax which normally works only for passive cards. As all active card you have to load its firmware (in this case after loading HiSax) from the file ISAR.BIN, which is part of the isdn4k-utils. Please note that compression (V42bis, MNP) are not implemented in firmware, and therefore not supported when using the analog modem. The ideal init string for the card to allow modem dialin is <tt>AT%C0\N0</tt>. If for some fax senders receiving by Hylafax does not work, then try to set the following configuration parameter for Hylafax: <code> Class1SwitchingDelay: 75 </code> The Sedlbauer Speedfax PCI is special in that it was produced just for Linux - there is no driver for it under Windows. <sect1> hardware_teles: What should I know about before buying an ISDN card from Teles? <label id="hardware_teles"> <p> First the latest news: according to the German magazine ct 02/2001, Teles has closed down its business activities in the ISDN area. Therefore, this FAQ does not really apply any more. However, I'll keep this FAQ for now to document Teles' attitude towards their customers. The author has had personal experience with Teles since 1994. One of the most frequently asked questions for Teles cards: The Teles card 16.3c has a crippled FIFO, therefore it is required to use <tt/AT&B1024/ when using the ttyI* devices (if the remote side still send packets with more than 1024 bytes it will not work - unfortunately many CAPIs use 2048 bytes as default). The latest Teles PCI card needs the <tt/netjet/ driver, the teles driver will NOT work (that card identifies itself as 'TigerJet Tiger300' when doing a <tt>cat /proc/pci</tt>). Now some comments about Teles in general (these are the personal opinions of the author of this FAQ, please blame nobody else than me): Teles' business practices are very customer- and developer-unfriendly when compared to those of other companies. Naturally, the developers give priority to cards for which support is available, and where the specifications are freely available. So far, Teles has had a very unfriendly attitude towards the i4l developers. No support has ever been received from them, and they don't publish any information about how to access their card. The developers have invested a lot of private effort into getting this card to work from the beginning without receiving any support. The driver has been a complete private effort. Yet, Teles has bragged on their web site that their cards run under Linux, without giving proper credit. Even companies that buy Teles cards and resell them under their own name have not been able to improve the support. This has lead to the situation where a re-branding company (!) itself had to go through the effort of obtaining approval to legally use i4l in Germany on a Teles card. From a customer point of view, check out the prices for their hotline before you buy any hardware from them! The author of the FAQ refuses to use any hotline that charges 216,- DM per hour. Reports about quality and waiting time have not always been favorable. And this company did not even give away drivers for other operating systems, like Windows, for free for many years (I know about 1995-2000). Only since about April 2000 you can download the drivers over the Internet. Before you had to dial up a very expensive number (0190) where you had to pay about DM 1,20 per minute in Germany to download the driver. Not that it's advisable to use Windows anyway, but just to let you know... Warning: Teles has often changed their cards without notice, while still using the same name. When you buy a Teles card, you may find out that your brand-new card can not be supported by i4l! (As has happened many times in the past...) The developers will try to support new Teles cards when information about how to access it becomes available, and when they have no other priorities. Of course you can always send a patch. <sect1> hardware_fritz: What should I know when configuring a Fritz! card (also known as: AVM A1, Teledat 150, BT Speedway)? <label id="hardware_fritz"> <p> The Fritz! card comes in different variations. Since the PCI card and the ISA/PNP card have the same type (27), hisax will assume an ISA/PNP card if you pass an io address, and a PCI card if you do NOT pass an io address. Make sure to give the parameters properly. The newest Fritz! PCI card (v2.0) is now supported by a new driver, however it has not yet been tested thoroughly. The card can be identified by lspci returning 0e00 as the card id. If the interrupt for the card is shared with other devices and your card does not work, then there could be an issue with the motherboard. See question <ref id="hardware_irqsharing" name="hardware_irqsharing"> for this. One very interesting thing: the Fritz! card is currently the only passive card for which a capi driver exists. As a result, it can be configured to fax. See question <ref id="feature_capi" name="feature_capi"> and <url url="http://www.avm.de/ftp/cardware/fritzcrd/linux/index.htm"> for more information on this. Usage of the capi driver is completely optional, you might as well stay with the standard driver if you do not need capi support. <sect1> hardware_avmb1: What is special about the AVM B1 card? <label id="hardware_avmb1"> <p> This card supports many special features in its firmware and is very well supported by its Linux driver. It's currently one of the only ISDN cards that you can use to fax under ISDN4LINUX, or which supports the CAPI 2.0 interface. You can get the newest driver from: <url url="ftp://calle.in-berlin.de/pub/capi4linux/">. To get the firmware download the two perl scripts from: <url url="ftp://calle.in-berlin.de/pub/capi4linux/firmware/"> They will download and extract the firmware from tar files on the avm ftp server on: <url url="ftp://ftp.avm.de/cardware/b1/linux/">. To use the AVM on a point-to-point connection (&dquot;Anlagenanschluss&dquot;) add &dquot;DSS1 P2P&dquot; to the load command for the firmware, like: <code> avmcapictrl load /usr/lib/isdn/b1.t4 0 DSS1 P2P </code> There is also a mailing list for problems with the AVM B1 available. Visit <url url="https://mlists.in-berlin.de/mailman/listinfo/linux-avmb1"> for more details about it. <sect1> hardware_hypercope: What is special about the Hypercope cards? <label id="hardware_hypercope"> <p> These cards support several special features in their firmware. They are newly supported by a Linux driver. They are currently one of the only ISDN cards that support the CAPI 2.0 interface. Also, you can use them very well for faxing under ISDN4LINUX (after upgrade with a fax card - possible for HYSDN Ergo2 and HYSDN Metro4). More information on company and hardware is available on: <url url="http://www.hypercope.de"> Configuration is similar to that of an AVM B1. <sect1> hardware_icn: What is special about the ICN card? <label id="hardware_icn"> <p> This was the first active card supported by isdn4linux. The manufacturer has always supported i4l developers (<tt><url url="http://www.think.de/"></tt>). The ICN does not need any interrupt (polling), therefore a PC can be equipped with many of them without any interrupt conflicts. The newest firmware should be available at <tt><url url="ftp://ftp.think.de/pub/isdn4linux/icn/firmware/"></tt>. Unfortunately, the ICN is not produced any more. <sect1> hardware_isurf: What should I know about the Siemens I-Surf cards? <label id="hardware_isurf"> <p> There are several interesting things. <itemize> <item> Two Versions: There are two different versions (version 1.0 and version 2.0) with a different chipset. Both work fine, however you have to set the type properly (29 for version 1.0, 12 for version 2.0). <item> PnP bug: Due to a bug in the pnp chip it is very important for the I-Surf 1.0 to have the following PEEK and POKE lines in your isapnp file to properly initialize the PnP register: <code> (MEM 0 (BASE 0x0c8000) (MODE bu) (UPPER 0x0c8400)) # (MEM 0 (BASE 0x0c8000) (MODE br) (UPPER 0x000400)) (REG 0x31 (PEEK)) (REG 0x31 (POKE 0)) (REG 0x31 (PEEK)) (ACT Y) )) </code> <item> Memory mapping: Since the I-Surf 1.0 uses memory mapping for the ISA bus, ensure that the used memory area is not shadowed or cached (see BIOS setup). <item> Firmware loading: Before usage you have to load the firmware: <code> hisaxctrl <id> 9 ISAR.BIN </code> (You find the file ISAR.BIN in the isdn4k-utils or on the I-SURF cd.) <item> Fax: The I-Surf 1.0 can be setup to send and receive faxes (see question <ref id="feature_fax" name="feature_fax"> for details). </itemize> <sect1> hardware_diva: What should I know about the Eicon Diva cards? <label id="hardware_diva"> <p> In general, a dedicated driver exists which supports the active Eicon Diva cards very well. The Pro series are not supported by isdn4linux since it is a semiactive card with a DSP as a B-channel controller. There is no code available in isdn4linux to dynamically load DSP programs into the card. However, check Eicon's website; maybe by now they provide pre-compiled driver for their cards not supported by isdn4linux. <!-- Trouble Hardware --> <sect1> hardware_crossedcable1: If i4l uses one B-channel then the other one will be blocked (incoming as well as outgoing)... <label id="hardware_crossedcable1"> <p> This behavior is typical for a cable with confused a/b wiring. Some NT from Quante had a wrong labeling. They caused exactly the mentioned behavior if the PBX was connected to the plug of the NT and the ISDN card to the pins of the NT. As soon as some device activates the bus the other one can no longer get through. <sect1> hardware_crossedcable2: How can I test whether a a/b cable pair has been crossed? <label id="hardware_crossedcable2"> <p> This question assumes that you are connected by an internal bus that you installed, attached directly to the NT (without using an RJ45 cable). The easiest way to test it is to buy a little cable tester (the author of this FAQ got one from Conrad Electronics in Germany for 29,- DM - just follow the simple instructions). Otherwise you have a bit more work. Switch line a1 and b1. If it doesn't work, put them back and switch a2 and b2. If it still doesn't work, try switching them both. As long as {a|b}1 and {a|b}2 are kept, nothing can break. If you want to be sure, before plugging it in measure between pins 4 and 5 and between Pins 2 and 6 on the socket; there should be no current, but between 3 and 4 and between 6 and 5 should be 40 V, 6 and 3 positive. With the Western plug this works similar. 4 lines are used: <verb> | | | | | | | | 1 2 3 4 </verb> Then you can try to switch (1 with 4) or (2 with 3) or both. Never switch the outer with the inner lines - this would cross the RX and TX lines and nothing will work. Check the Cable FAQ for more details on which line should be connected how. If both devices are attached via RJ45, then one of the cables has been twisted. That usually happens if one of the RJ45 plugs has been attached upside-down (a1/b1 are inside, a2/b2 are outside, so the order of the sending/receiving pairs is maintained), then you just need a new plug and of course pliers for the RJ45, old plug off, and new plug (in the right direction) on. <sect1> hardware_pbx: i4l is connected to the internal bus of a PBX. Any problem? <label id="hardware_pbx"> <p> Many PBX run non-standard ISDN protocolls on their internal bus. In old versions (before end of August 2003) this could cause i4l to print warnings like "Unexpected discriminator 0xZZ" (where ZZ is a hexadecimal number) when it encounters unexpected frames (some old versions even crash). This can increase your message file by as much as 1 MB in 3 days. The PBX <tt>Ackermann Euracom 181</tt> (discriminator 0xaa) as well as <tt>Ascom</tt> (discriminator 0x44/0x47) seem to be notorious for this. You can avoid the warning by adjusting the switch/case code for isdnlog in function <tt>processctrl(...)</tt> in <tt>processor.c</tt> and recompiling isdnlog. Since August 2003 ignoring these unknown packages has become the default, therefore the recompile is not necessary any more. Please note that isdnlog will not be able to log any incoming data packages, since the PBX has to forward the packages. To see everything, you have to bypass the PBX. Please be aware, that the PBX may hang if the ISDN card does not respond to the PBX requests - bypass the PBX in such a case. Also, a PBX may run 1TR6 protocoll on the internal bus by default, rather than Euro ISDN. You have to configure i4l (or the PBX) accordingly, best is you try to configure both on the same or similar protocolls. Also the MSN may be different than you expect. Check several versions, no digit (then use <tt>0</tt>, which i4l will require in such a case), one digit, or two digits, or the whole MSN. Best is you call some device (e.g. ISDN telephone) on the internal bus and check what i4l writes into the log file. When you can not dial out, the most common problem is that you have not set the MSN properly for outgoing calls, which causes the PBX to refuse your request. For dial in be aware that some PBX add a leading 0 to any incoming telephone number, so adjust your configuration for the secure option accordingly. Last, remember that you may have to configure your PBX to 'route' incoming calls onto the internal ISDN bus. If you have a point-to-point configuration ('Anlagenanschluss') then you cannot connect your card directly to the S0 bus in parallel to the PBX (otherwise nothing will work). You have to connect to an internal ISDN bus. Your MSN is usually the extension at the end of your telefon number. If your PBX is the <tt/Ackermann Euracom</tt>, then you may also check out this German site for the configuration software maKs: <url url="http://www.ganzfix.de"> <sect1> hardware_telestrouble: The PNP tools done work with my Teles 16.3 PNP card! <label id="hardware_telestrouble"> <p> It's probably not a Plug 'n Play card at all - even though Teles now prints PNP on all their card and packaging. The difference is easy to recognize: a real Teles PNP card no longer has the (tiny) Dip switches on the card to set the IO addresses. <sect1> hardware_elsacabletrouble: On my ELSA card, the LED for the loss of the TEI often blinks. My connections are also often disrupted... <label id="hardware_elsacabletrouble"> <p> These blinking LEDS are often caused by a bad cable or a too long or unterminated SO bus. <sect1> hardware_elsairq: My ELSA Quickstep 1000 ISA card produces very many interrupts with the HiSax driver. Is this normal or a problem with the HiSax driver? <label id="hardware_elsairq"> <p> This is normal. The ELSA Quickstep 1000 ISA card has a hardware timer on the card which can not be disabled by software. You have to modify the card hardware to get rid of it. Check with Karsten Keil for this: <tt><htmlurl url="mailto:keil@isdn4linux.de" name="keil@isdn4linux.de"></tt> <!-- Configuration/Troubleshooting --> <sect> config: General information about Configuration <label id="config"> <sect1> config_msn: How should I set up isdn4linux with my MSNs? <label id="config_msn"> <p> See section <ref id="msn" name="msn">. <sect1> config_hardware: How should I configure my hardware? Is there something special I should know about my ISDN card? <label id="config_hardware"> <p> Have a look in section <ref id="hardware" name="hardware">. <sect1> config_dialout: How should I configure dialout? <label id="config_dialout"> <p> See section <ref id="dialout" name="dialout">. <sect1> config_dialin: How should I configure dialin? <label id="config_dialin"> <p> See section <ref id="dialin" name="dialin">. <sect1> config_suse: I can not select my card in yast? <label id="config_suse"> <p> If you have a SuSE distribution, and you can not find your card in yast, then select card <tt/generic/ and enter the exact parameters in the special case line, like: <tt>type=27 protocol=2</tt> for Fritz!PCI and Euro ISDN. Get a newer kernel if the desired type is not yet supported. <sect1> config_pnp: How do I configure a PNP (Plug and Play) card? <label id="config_pnp"> <p> For PCI cards Plug and Play works automatically, they don't need any manual configuration if the correct card type is provided. ISA PNP cards will require some manual configuration: <enum> <item>With &dquot;make menuconfig&dquot; (or &dquot;make config&dquot;) set the following kernel options: <itemize> <item>ISDN = &dquot;M&dquot; (as module - otherwise PNP doesn't work!) <item>HiSax = &dquot;M&dquot; (as module - otherwise PNP doesn't work!) <item>16.3/PNP support <item>EURO support </itemize> <item>Compile and install kernel and modules, depmod. (Reboot!) <item>Read the configuration of the PNP card with: <code>pnpdump -c > /etc/isapnp.conf</code> <item>Verify whether pnpdump has prepared the configuration file <tt>/etc/isapnp.conf</tt> properly: <itemize> <item>INT0 - the interrupt used by the card (Default for Teles 16.3 PNP: 10). Make sure that interrupt 3 and 4 are not used, since they are reserved for the serial interface (which, unfortunately, the serial driver may have forgotten to reserve). <item>IO0, IO1 - the IO ports used by the card (Default for Teles 16.3 PNP: 0x580 and 0x180) (Attention: these values must be 64-bit aligned (ending with 0, 4, 8, or c)! Early versions of the PNP cards may suggest incorrect values!) <item>Comment removed in front of ACT Y! </itemize> <item>Activate the configuration with: <code>isapnp /etc/isapnp.conf</code> (must be started at every boot) <item>Now the HiSax module can be started for Euro-ISDN with: <code>modprobe hisax io=4,2,INT,IO0,IO1</code> (Replace INT, IO0, and IO1 with your values in isapnp.conf.) </enum> <sect1> config_startstop: How can I start and stop the ISDN configuration? <label id="config_startstop"> <p> There are several options: <itemize> <item> Reboot: rebooting your computer always works. If you compiled i4l into the kernel, then this is actually your only chance. The remaining options only work if you configure i4l using modules. <item> Manual: Unload the modules used by i4l with rmmod, then reload them with modprobe. <item> Runlevel: use telinit to switch to a runlevel which does not contain ISDN, then switch back to the original runlevel. <item> Scripts: most distributions come with start/stop scripts. For example, on a Suse 7.0 distribution, this will stop ISDN: <code> rcroute stop rci4l stop rci4l_hardware stop </code> This will restart ISDN: <code> rci4l_hardware start rci4l start rcroute start </code> </itemize> <sect1> config_kerneld: Why shouldn't I use <em>kerneld</em> to load the ISDN modules in the kernel as needed? <label id="config_kerneld"> <p> <em>kerneld</em> does not work well with the ISDN modules, since the ISDN modules can not store their status, and could miss important messages on the D channel. Newer versions of i4l ensure that they won't be unloaded by kerneld, but you should not try to use kerneld with any version of i4l. <sect1> config_runlevel: How can I boot Linux sometimes with ISDN, and sometimes without? <label id="config_runlevel"> <p> Yes, you can define two different run level for this (under SysVInit) in <tt>/etc/inittab</tt>. One run level includes the ISDN processes, where the other one does not. <sect1> config_manycards: How do I configure more than 1 ISDN card? <label id="config_manycards"> <p> There are some specialities for configuration of more than 1 card: <itemize> <item>You have to start a driver for every type of card you have, with the correct configuration arguments. <item>To handle more than 1 card with the same driver (e.g. HiSax should handle an ELSA and an ASUS card), you have to pass the configuration arguments for all cards to this driver. Please note, that you'll have to use modules for more than two cards, to pass all arguments. As an example, you can load HiSax for two Sedlbauer cards with the following command: <code> modprobe -v hisax protocol=2,2 type=28,28 </code> <item>Driver ID: the HiSax driver uses 'HiSax' as the default for a driver id if you have only one card. For more cards you have to set the id explicitely, e.g. for two cards in the form of <code> id="contr0%contr1" </code> <item>Dialin of many people at the same time: have a look at question <ref id="dialin_manyparallel" name="dialin_manyparallel">. <item>Dialout through several cards: have a look at question <ref id="dialout_manycards" name="dialout_manycards">. </itemize> <sect1> config_manychannels: How can I increase i4l's maximum number of channels? <label id="config_manychannels"> <p> Increase the parameter ISDN_MAX_CHANNELS in <tt>/usr/src/linux/include/linux/isdn.h</tt> and rebuild the isdn stuff. Don't forget to create the additional devices with makedev.sh (part of isdn4k-utils) or by hand. <sect1> config_gsmv110: How do I connect my PalmPilot via GSM over V.110 to my computer? <label id="config_gsmv110"> <p> A connection via GSM will first go to the GSM provider via a special air transmission protocol. To forwarding the data on to an analog or ISDN line, an adapter called IWF (interworking function) has to translate this into the analog or ISDN specific transmission protocol. Which analog or ISDN transmission protocol is being used depends on how the mobile phone requests its GSM connection. An analog connection is not very attractive due to the lengthy modem handshaking on dialin. For ISDN, HDLC and X.75 are currently not supported by the IWF, so the choices are down to V.110 and V.120. V.120 has better flow control and error correction, but currently isdn4linux only supports V.110. On the dialup server set up async PPP with a normal pppd on a ttyI* device (sync ppp will not work). Additionally to setting the msn, you have to set V.110 and the transmission rate to 9600 with <tt/AT&R9600/ (<tt>/usr/src/linux/Documentation/isdn/README</tt> gives more details on the V.110 bitrate adaption for this command). Switch off autoanswer with <tt/ATS0=0/ if you use mgetty. pppd needs to be called with <tt/noccp/ and <tt/require-pap/. On the GSM mobile phone side, request an ISDN V.110 connection with the command <code> AT+CBST=71,0,1+CHSN=1,0,0,0 </code> For a Nokia 7110, you may have to use the undocumented command <code> AT+CBST=75,0,1 </code> If the bearer capability is reported as &dquot;88 90 21 48 06 bb&dquot; by isdn4linux, then you have set it correctly (88 90 21 means V.110, 48 means ASYNC 9.6kbit, 06 means flowcontrol RX/TX, bb means 8 bit 1 stop none parity). If the call is indicated with service indicator byte 2 = 0 and not accepted (happens with some wrongly configured PBX), then adjust with <tt/ATS19=0/. A higher bandwidth of 19.2kbit (HSCSD) could be requested with the command <code> AT+CBST=81,0,1+CHSN=3,0,0,0 </code> but you can not be sure that your GSM provider will really use this rate. Configure your dialin server accordingly. For a mini-howto see: <url url="http://www.oltom.com/Linux/Docs/GSM%20over%20V.110%20Mini-HOWTO.txt"> <sect1> config_h323: How do I configure isdn4linux to act as a voice-over-ip gateway for H.323 clients? <label id="config_h323"> <p> You have to install the Linux H.323 - ISDN Gateway, which can be found on <url url="http://www.telos.de/linux/H323/">. Please note that not all sound cards support full duplex audio. Depending on your hardware you may end up with uni-directional voice. <sect1> config_point2point: How do I configure a point-to-point connection? <label id="config_point2point"> <p> First of all, the point-to-point connection will only work for one single device connected to it - therefore nothing else but your ISDN card may be attached to it. You can switch HiSax into point-to-point mode: <code> hisaxctrl <driver_id> 7 1 </code> Additionally, you can use the &dquot;AT&Lxxx$dquot; command to configure the range of telephone numbers isdn4linux should be listening to on the ttyI* devices. If you really absolutely want to run your ISDN card for read-only purposes in parallel to your pbx on a point-to-point connection, then you have to disconnect the RX leads (pin 3 and 6 on western plug), so that the NTBA will not see the ISDN card. In this case configure HiSax normally, NOT in point-to-point mode. <sect1> config_links: What helpful links are there about and around isdn4linux? <label id="config_links"> <p> These are helpful links that are currently available on how to configure isdn4linux: <itemize> <item>English: <url url="http://www.wurtel.cistron.nl/i4l-howto-uk.html"> <item>Dutch: <url url="http://www.wurtel.cistron.nl/i4l-howto-nl.html"> <item>German: <url url="http://www.franken.de/users/klaus/"> <item>French: <url url="http://www.linux-france.org/article/connex/ISDN/"> and <url url="http://www.linux-france.org/prj/inetdoc/guides/rnis/"> <item>Suse Support database: <url url="http://sdb.suse.de/sdb/en/html/index.html">; there is also an ISDN howto (isdn.html) and a ISDN quick-install guide (isdnquick.html). <item>Tips to configure Suse (and about offline reading): <url url="http://www.schlenn.de/isdn4linux/"> <item>Tips to configure Red Hat: <url url="http://www.webideal.de/rh-isdn/"> <item>Tips to configure Mandrake: <url url="http://www.mandrakeuser.org/connect/cisdn.html"> <item>Tips to configure Gentoo: <url url="http://forums.gentoo.org/viewtopic.php?t=29991"> <item>fli4l, a prepackaged Linux version to use an old PC as ISDN router: <url url="http://www.fli4l.de"> (great!) <item>LR101 (a project which tries to create a hardware router based on Linux): <url url="http://lr101.linux-it-solutions.de"> <item>Scripts and installation tips from several people: <tt><url url="http://www.rosat.mpe-garching.mpg.de/˜web/ISDN.html"></tt> <item>Documentation on abc extensions: <tt><url url="http://i4l.mediatronix.de/"></tt> <item>Installation of CAPI4LINUX, CAPI4LINUX, and CAPI4Hylafax (in German): <tt><url url="http://ixi.thepenguin.de"></tt> or <tt><url url="http://capi4linux.thepenguin.de"></tt> or <tt><url url="http://www.thepenguin.de"></tt> <item>Vbox development: <tt><url url="http://innominate.org/projects/vbox/index.php3"></tt> <item>Michael Hipp's page (general informations): <tt><url url="http://www-ti.informatik.uni-tuebingen.de/~hippm/isdn.html"></tt> <item>Chargeint tips: <tt><url url="http://www.auf-der-er.de/chargeint.html"></tt> <item>Homepage of linecontrol (manage isdn dialing similar to kisdn): <tt><url url="http://linecontrol.sourceforge.net"></tt> <item>(German) Homepage of ISDN Sniffer (read ISDN bus, e.g. via reversed card): <tt><url url="http://krypt.cs.uni-sb.de/projects/isdnsniffer/"></tt> <item>Homepage of Asterisk (Open Source Linux PBX): <tt><url url="http://www.asterisk.org"></tt> <item>Homepage of ivcall (send and receive fax/voice calls): <tt><url url="http://0pointer.de/lennart/projects/ivcall/"></tt> <item>Configuration software maKs for Ackermann Euracom (not isdn4linux related): <tt><url url="http://www.ganzfix.de"></tt> </itemize> <sect1> config_misdn: How should I configure the new mISDN driver, and what is so special about it? <label id="config_misdn"> <p> The mISDN driver stands for modular ISDN. It is a complete rewrite of the old isdn drivers and now communicates via CAPI messages. The mISDN driver is retire the historical drivers once it is fully functional within the 2.6.x kernels. As a temporary work around the historical drivers have been ported into the early 2.6.x kernels to get isdn working, however, this will be fixed in later versions. To start mISDN, you have to load all the following modules: <itemize> <item>capi <item>mISDN_core <item>mISDN_l1 <item>mISDN_l2 <item>l3udss1 <item>mISDN_capi <item>mISDN_isac (for isa card) <item>Hardware specific driver (e.g. hfcpci, or avmfritz) </itemize> Not all features are available. It is currently not planned to port 1TR6 (the ancient ISDN protocoll in Germany) to the new driver. For more information on how to configure it have a look at the following website: <tt><url url="http://rcum.uni-mb.si/~uvp00845b/"></tt> For a more general description on the mISDN driver and the future of isdn4linux you may also read the German article published in ct 3/2004. An online version is available at: <tt><url url="http://www.heise.de/ct/04/03/182/"></tt> Please note that the current FAQ applies to old isdn drivers. mISDN may work differently than described in this FAQ. Please let me know about any amendmends for this FAQ. <sect1> config_kernel26: What has changed with the kernels 2.6.x? <label id="config_kernel26"> <p> With the kernels 2.6.x the mISDN driver has been introduced (see question <ref id="config_misdn" name="config_misdn">). It is planned that the mISDN drivers will replace the old isdn4linux drivers like HiSax, which have been ported to 2.6.x only since mISDN was not ready yet. Please note that the ported drivers have not been upgraded to make use of the new kernel features like devfs. You still have to create all the devices you need, either with makedev.sh (part of isdn4k-utils), or by hand. Some distributions will do that for you (e.g. Suse), for others you have to do this yourself (e.g. Mandrake 10). <!-- Troubleshooting --> <sect> trouble: Troubleshooting <label id="trouble"> <sect1> trouble_22memory: I can't start ISDN on my machine with kernel 2.2.x. I get the error messages "init_module: Device or resource busy" and "isdn: Could not allocate device-struct.". <label id="trouble_22memory"> <p> This is a memory problem and means you don't have enough <bf>unfragmented</bf> memory. While 2.0.x kernels may work on low memory/slow hardware (the author's answering machine is a 386 and used to run with 4MB of RAM), you can run into the memory fragmentation problem even if you have as much as 32MB of RAM when running 2.2.x kernels. The problem has been eased since 2.2.14, when ISDN4LINUX's memory allocation has been changed to use vmalloc. You can try to reduce the memory requirements (see question <ref id="trouble_littlememory" name="trouble_littlememory">), compile ISDN4LINUX into the kernel, or start and then exit a large program to ease the memory fragmentation problems. <sect1> trouble_littlememory: How can I reduce isdn4linux's memory requirements? <label id="trouble_littlememory"> <p> Try to do the following things: <itemize> <item> Stick with kernel 2.0.x if you have a 486 or lower. <item> In <tt>/usr/src/linux/include/linux/isdn.h</tt>, change the line <code> #ifdef CONFIG_COBALT_MICRO_SERVER </code> into: <code> #if 1 </code> and recompile kernel. <item> Reduce ISDN_MAX_DRIVERS, ISDN_MAX_CHANNELS in <tt>include/linux/isdn.h</tt>, then recompile kernel. </itemize> <sect1> trouble_debug: How do I get maximum debug output? <label id="trouble_debug"> <p> Execute the following commands to get maximum debug output: <code> hisaxctrl <id> 1 0x33ff hisaxctrl <id> 11 0xf4f killall isdnlog cat /dev/isdnctrl > /tmp/ilog </code> Be careful: this will generate a lot of output! <sect1> trouble_strategy: My isdn4linux doesn't work! How do I best go about finding the problem? <label id="trouble_strategy"> <p> The following steps are recommended: <enum> <item>Check everything is working when booting. Are there unusual error messages in /var/log/messages? Are all programs active that should be started at boot (check with ps, or fuser /dev/xxx)? HiSax won't start if something isn't right. Check question <ref id="trouble_boot" name="trouble_boot"> for what you can check. The old Teles driver, on the other hand, will appear to start even if it is not working. See the questions under Troubleshooting Teles. <item>Make sure you configured the ISDN driver either as modules, or you compiled them into the kernel - never both. <item>Try calling your dialin number with a telephone. The number should be shown in <tt>/var/log/messages</tt>. Check for a line like this: <code> Call from 0,1,2345 -> 6789 </code> This means that on channel 0 a call from 2345 with service indicator (SI) 1 (1 = voice; data would be 7) to MSN 6789 was received. Now at least you know that you have to configure your MSN to 6789 (or whatever other number you find there), and that your isdn4linux kernel driver understand ISDN commands coming from your ISDN card properly. If instead of the number 2345 you find a 0, then your ISDN provider does not pass you the caller id. If you don't find such a line: perhaps the driver was incorrectly started?! <item>As a next step we'll try to get the telephone or fax to ring by dialing ourself using a ttyI device with minicom. First we have to change the service recognition with the <tt>ATS18=1</tt> command to audio. Now you can get the telephone to ring by dialing <tt>ATDxxxxxx</tt>, where xxxxxx is your own MSN. <item>Next we try to transmit data via ISDN. Open 2 different consoles as root, and on each run &dquot;minicom -s&dquot;... in the first set &dquot;Serial Port Setup Serial Device&dquot; to <tt>/dev/ttyI0</tt>, and the other to <tt>/dev/ttyI1</tt>. Then choose &dquot;Exit&dquot; and start the modem emulation with &dquot;ATZ&dquot; and &dquot;AT&Exxxxxx&dquot; (where xxxxxx is your own MSN without the area code). Then you can start. On the first console you can dial your own number with ATDxxxxxx. On the second console you should now see &dquot;CALLER NUMBER: xxxxxxx&dquot; and &dquot;RING&dquot;. Accept the call on the second console with &dquot;ATA&dquot;, and you should then see the message &dquot;CONNECT 64000/X.75&dquot; on both consoles. You can then send characters to the other console by typing (to see the characters on your own console, turn on local echo). <item>Next, try calling a known ISDN BBS. If you don't know of any, try Gernot (see &dquot;Are there sites that offer guest access where I can test my isdn4linux setup?&dquot;). If you have problems with the modem emulation, see &dquot;Troubleshooting Modem Emulation&dquot; <item>Fifth, try configuring the network interface or ipppd. Experience shows that they cause beginners (and not only beginners!) the most problems. To make things easier and you're happy with asyncPPP (to see what asyncPPP means, see the question &dquot;pppd, ipppd, syncPPP, asyncPPP - what is that? What should I use?&dquot;), you can use the normal pppd with modem emulation (i.e. /dev/ttyI*). <item>Ensure that you set up your authentication configuration properly (see questions in section <ref id="pap" name="pap">. </enum> Otherwise, it is highly recommended that use an example script form the HowTo (see the question &dquot;Where can I find scripts and other information on configuring i4l?&dquot;). For testing you can try your own provider or of the guest accounts (see &dquot;Are there sites that offer guest access where I can test my isdn4linux setup?&dquot;). The latter have the advantage of being able to see the log files as well as a stable, working configuration. For example, if accessing via ipppd doesn't work, you can log in via modem or modem emulation to find out what happened on the other side. Not all providers are so cooperative.... :-) <sect1> trouble_boot: How can I tell whether my ISDN card has been correctly recognized? <label id="trouble_boot"> <p> <enum> <item>Check for error messages in the boot messages (you can review them at any time with the command <tt/dmesg/. <item>For the HiSax driver: During booting a message <tt>kernel: HSCX version A:5 B:5</tt> and <tt>kernel: channels 2</tt> should appear. <tt>A:4 B:4</tt> is also okay. Other values (in particular <tt>A:??? B:???</tt>) mean the card is not recognized correctly. HiSax is only loaded if the hardware can be found and the appropriate interrupts can be generated. This means the card is installed correctly in the computer, and there are no hardware conflicts. It does not mean that everything will work (e.g. twisted cables, broken cables, terminators). <item> Check that your card got an interrupt assigned, e.g. with <code> lspci -v </code> A common problem is that your BIOS did not assign an interrupt to your card. HiSax will then complain with "No IRQ for PCI card found". To fix, set the BIOS option "PnP OS" to NO. <item>Check that the interrupts are registered correctly. Check with <code> cat /proc/interrupts </code> The following entry indicates that the card is configured on interrupt 11, and so far has received 3 interrupts: <verb> 11: 3 + hisax </verb> When you call yourself, the number of received interrupts should increase. <item>Check the io ports with <code> cat /proc/ioports </code> </enum> <sect1> trouble_isdncause: I get an error message like "cause: E1234" (or similar)? <label id="trouble_isdncause"> <p> Just have a look at <tt>man isdn_cause</tt> to find out what the problem is. For the very popular cause "E001B" see question <ref id="trouble_e001b" name="trouble_e001b">. <sect1> trouble_e001b: I get an error message with "cause: E001B"? <label id="trouble_e001b"> <p> This is a very popular error and means (see <tt>man isdn_cause</tt>): euro ISDN (E), location user (00), and out of order (1b). Taken together means that the driver either can't get a layer 1 connect (cable problem, hardware error, hidden hardware conflict - see section <ref id="hardware" name="hardware">), or it can't get a layer 2 connect (wrong configuration: no Euro ISDN, no automatic TEI supported, point-to-point BRI instead of multi-device - see section <ref id="config" name="config">). <sect1> trouble_noprotocol: upon startup of HiSax I get the message &dquot;Warning - no protocol specified&dquot;? <label id="trouble_noprotocol"> <p> This means that you did not specify which D-channel protocol you want to use with HiSax. In most cases this is wrong, and you have to specify that you want to use the Euro Protocol ISDN DSS1. Only if you have a leased line you don't need to specify any D-channel protocol. <sect1> trouble_euronotsupported: upon startup of HiSax I get the error "kernel hisax: protocol euro not supported"? <label id="trouble_euronotsupported"> <p> This means that you did not select the Euro Protocol ISDN DSS1 option when compiling your kernel. You have to switch this on and recompile your kernel to be able to use it. <sect1> trouble_unknownprimitive: upon connection attempt I get the error "lldata_handler unknown primitive"? <label id="trouble_unknownprimitive"> <p> This means that the link level protocols do not match (e.g. you tried to connect with X.75, whereas your provider answers with HDLC). Check and fix your connection parameters with: <code> isdnctrl l2_prot <interface> <protocol> </code> <sect1> trouble_notelrings: Neither my telephone nor my fax machine ring when I call them with isdn4linux? <label id="trouble_notelrings"> <p> Isdn4linux sets &dquot;digital data&dquot; as it's own service when it calls out. The switching station does in fact route such calls to analog devices like a telephone or a fax machine. However, since the machine is analog, it will only answer analog call, and ignore the digital data call. <sect1> trouble_guestaccess: Are there sites that offer guest access where I can test my isdn4linux setup? <label id="trouble_guestaccess"> <p> The following information is quite old. Please tell me if you find out that the guest sites are not available any more: The following sites offer guest access for modem emulation or IP: <itemize> <item>Eberhard Moenkeberg <tt><htmlurl url="mailto:emoenke@gwdg.de" name="emoenke@gwdg.de"></tt>: <itemize> <item>Welcome to Linux at eberhard.moenkeberg.de (LAN, Under ++49-551-7704103, ISDN NetCalls (HDLC-trans-rawip) for get accepted. You should come as 192.168.*.* because sometimes my &dquot;default&dquot; route is not your way. /ftp is exported for NFS; try &dquot;showmount -e&dquot;. You can login as &dquot;guest&dquot; without password. FTP as &dquot;gast&dquot; with password &dquot;gast&dquot; avoids the restricted shell. <item>Under ++49-551-7704102, a 28800 bps modem and a Creatix ISDN card (HDLC only, not X.75) are listening for logins. <item>With the net setup from <tt><url url="ftp://ftp.gwdg.de/pub/linux/isdn/isdn4linux-gwdg/rc.isdn-Beispiel"></tt> you can test NetCall at 551-7704103 (works as is within Germany, from outside Germany you just have to change the number). </itemize> <item>Gernot Zander <tt><htmlurl url="mailto:hifi@scorpio.in-berlin.de" name="hifi@scorpio.in-berlin.de"></tt>: <quote> There's a &dquot;gast&dquot; at +49 30 67 19 81 01 (X.75, mgetty). There's the stones-html-page with pics in postscript to test downloading. Whoever needs a target to call can use it. At ...81 03 there's a getty with HDLC. As guest you enter a kind of BBS and can read some news. </quote> </itemize> <sect1> trouble_unload: I can't unload my ISDN modules (&dquot;isdn: Device or resource busy&dquot;), even so I closed all ISDN applications? <label id="trouble_unload"> <p> In this case &dquot;fuser -v /dev/isdn* /dev/ippp* /dev/cui* /dev/ttyI*&dquot; is very helpful. This helpful program shows, which processes are using those devices. <itemize> <item>Is some program still using an ISDN device? <item>Did you remove all getty's? (They may have restarted automatically) <item>Are isdnlog, imon, iprofd, etc., still running? <item>Maybe there is still a route on your net interface and it's not yet deleted with &dquot;route del xxx&dquot;? <item>Maybe the net interface wasn't put down. This can easily happen when killing ipppd. It does not react to signal 15 and has to be killed with &dquot;kill -9 ipppd pid&dquot;. Then the net interface is left &dquot;up&dquot;. </itemize> Sporadic errors of this type can be fixed by inserting sleep commands between the unloading commands. As a very, very last resort, there are two secret telesctrl commands to adjust the module counter: <code> telesctrl id 3 1 --- dec module_count telesctrl id 4 1 --- inc module_count </code> Please use with appropriate caution and on your own risk! <sect1> trouble_tcpdump: Why does my tcpdump not work for ip packets going over ISDN (&dquot;truncated ip&dquot; or so)? How can I get a tcpdump patched for ISDN? <label id="trouble_tcpdump"> <p> The reason is that tcpdump does not always understand the special encapsulations that are possible with isdn4linux, especially syncppp. To change this, you need to patch tcpdump. Michael Stiller <tt><htmlurl url="mailto:michael@toyland.ping.de" name="michael@toyland.ping.de"></tt> wrote on 23 Oct 1996: Tip for ftp: <tt><url url="ftp://ftp.gwdg.de/pub/misc/isdn/linux/isdn4linux-gwdg"></tt> There is the patch: &dquot;tcpdump-3.0.4-1-isdn.dif.gz&dquot; and the rest is at: /pub/linux/mirrors/funet/PEOPLE/Linus/net-source/tools/tcpdump-3.0.4-1.tar.gz You might need to hack some, depending on the name of your ISDN interface (mine is bri0). By default, it recognizes only isdn* and isdnY* as interface names. Henning Schmiedehausen <tt><htmlurl url="mailto:henning@pong.iconsult.com" name="henning@pong.iconsult.com"></tt> further wrote on 30 Oct 1996: <quote> After finding the patch from Eberhard Moenkeberg at ftp.gwdg.de cannot dump cisco HDLC, I made my own patch for tcpdump-3.0.4 that asks the interface which encapsulation it used and sets itself accordingly. The patch is against a tcpdump-3.0.4-1.tar.gz distribution, for example at </quote> <tt><url url="ftp://ftp.funet.fi/pub/Linux/PEOPLE/Linus/tools"></tt> <quote> This patch recognizes rawIP, ISDN-IP and CISCO-HDLC and can dump these packets. </quote> (The patch was attached to the message - it should be easy to find in the mailing list archive - Ed.) Sascha Ottolski <tt><htmlurl url="mailto:sascha@alzhimer.isdn.cs.tu-berlin.de" name="sascha@alzhimer.isdn.cs.tu-berlin.de"></tt> gave the following tip on 5 Nov 1996: <quote> This is a isdn4k-utils-2.0/tcpdump-3.0.3-isdn.diff ! It work, if one makes some changes: In the file tcpdump-3.0.3-isdn/libpcap-0.0/pcap-linux.c after patching you find the following: else if (strncmp(&dquot;ppp&dquot;, device, 3) == 0) Either you name your ppp devices pppX instead of ipppX, or change this line, e.g. else if (strncmp(&dquot;ippp&dquot;, device, 4) == 0) ^^^^ ^^ Then tcpdump will also recognize syncPPP. At least it does for me. </quote> <sect1> trouble_locatecrash: My isdn driver crashes my machine! Since I've configured it as a module, the addresses change each time it's loaded. How can I find out where the driver is crashing? <label id="trouble_locatecrash"> <p> The driver should be loaded with the command &dquot;insmod -m&dquot;. The output has to be transformed somewhat to be a form similar to System.map. You can do it like this: <code> insmod -m isdn.o | sort | sed -e 's/ / T /g' | egrep '.* T (a-z,A-Z,_)+' /etc/isdn/isdn.map cat /System.map /etc/isdn/isdn.map /iSystem.map </code> (The line ending with &dquot;|&dquot; has to have the following text on the same line!) iSystem.map should then be used instead of System.map for finding the error. <sect1> trouble_lotsdebug: My hard disk becomes very active when isdn4linux run. How can I turn this off? <label id="trouble_lotsdebug"> <p> Check whether the reason for the hard disk activity is caused by the amount of messages written into the logfile. If this is the case, you can reduce the output by: <code>isdnctrl verbose 0 </code> and/or by removing the &dquot;debug&dquot; option for ipppd. <sect1> trouble_oldhardware: Maybe my hardware is too slow? <label id="trouble_oldhardware"> <p> Actually, properly configured, isdn4linux will on much smaller machines, than you might expect (still running an elder version on my 386-25, which used to have only 4MB RAM). However, newer isdn4linux/kernel versions need more memory, and may require some tweaking before they run on very old hardware. Have a look at question <ref id="trouble_outofbuffers" name="trouble_outofbuffers"> when running out of buffers. See question <ref id="trouble_littlememory" name="trouble_littlememory"> on how to reduce the amount of memory needed. <sect1> trouble_outofbuffers: I get messages like &dquot;HSCX RME out of buffers&dquot;, &dquot;HSCX RFP out of buffers&dquot;, &dquot;HSCX B EXIR 10&dquot; in the syslog? <label id="trouble_outofbuffers"> <p> These errors happen when i4l is not able to process its buffers fast enough. They are often caused by bad sound cards or their drivers when they disable the interrupts too long! It may also happen on old hardware (happened to the author of this FAQ when using <tt/vbox/ on an old 386-25 with only 4MB RAM). You may be able to work around it by increasing the number and size of the buffers. Check the source code header files for definitions like: <code> #define HSCX_RBUF_ORDER 1 #define HSCX_RBUF_BPPS 2 #define HSCX_RBUF_MAXPAGES 3 </code> The first two influence the size, the last one the maximum number of buffers. <sect1> trouble_noresetinit: After a soft reset, my card does not initialize correctly. <label id="trouble_noresetinit"> <p> After you stopped your system with the <tt/reboot/ command or with <tt/Ctrl-Alt-Del/, press the reset button (=hard reset). Sometimes the card needs to receive a hardware signal to reinitialize properly. <sect1> trouble_noisdnctrl: When attempting to use isdnctrl, I get the error &dquot;/dev/isdnctrl: No such file or directory&dquot;? <label id="trouble_noisdnctrl"> <p> First check whether there is a device /dev/isdnctrl0. If there is, just create a symbolic link by executing <code> ln -s /dev/isdnctrl0 /dev/isdnctrl </code> If the device is not there, run the script <tt>scripts/makedev.sh</tt>, which is part of the isdn4k-utils. <sect1> trouble_noisdnctrl2: When attempting to use isdnctrl, I get the error &dquot;/dev/isdnctrl: No such device&dquot;? <label id="trouble_noisdnctrl2"> <p> In contrast to &dquot;/dev/isdnctrl: No such file or directory&dquot; the message &dquot;/dev/isdnctrl: No such device&dquot; indicates that the device /dev/isdnctrl exists, but no ISDN device driver is available. To fix, load the ISDN modules (verify with &dquot;cat /proc/modules&dquot; that they are loaded) or compile the ISDN drivers into the kernel. <sect1> trouble_xosview: xosview doesn't show any network activity since installing i4l. <label id="trouble_xosview"> <p> Peter Hettkamp <tt><htmlurl url="mailto:Peter.Hettkamp@kassel.netsurf.de" name="Peter.Hettkamp@kassel.netsurf.de"></tt> wrote: <quote> xosview reacts, at least for me with version 1.4, to the IP accounting in the kernel. So, configure, if necessary build a new kernel, then couple with: ipfwadm -A -a -S your-ip-address-here -D ipfwadm -A -a -D your-ip-address-here -S (I don't know who it works with variable IP addresses. I have a fixed address.) </quote> <sect1> trouble_unknownhost: When I for example from a W95 box call up a page with Netscape, I only get the answer &dquot;unknown host&dquot;. <label id="trouble_unknownhost"> <p> What is entered on the &dquot;Win95 box&dquot; for the name server? As long as the router has no name server of its own, then the provider's name server of course has to be entered on all computers on the LAN. <sect1> trouble_noroute: Addresses are now found, but now I get &dquot;no route to host&dquot;. <label id="trouble_noroute"> <p> Please check: <itemize> <item>Is the Linux computer entered as the gateway? (Some 'operating systems' have to be restarted before changes to the networking take effect)? <item>Does the router have a default route to the prepared interface to the provide (e.g. ippp0 with syncPPP or sl0 for diald (even when the real connection is over ppp0, diald uses a slip interface as a &dquot;doorknob&dquot;) <item>Does the provider require the use of proxies? Then the addresses of the proxies have to the entered in the appropriate clients on the LAN computers <item>Maybe your route was removed when using syncppp? Check the questions <ref id="syncppp_noroute" name="syncppp_noroute"> and <ref id="syncppp_nodefaultroute" name="syncppp_nodefaultroute">. </itemize> <sect1> trouble_nolocalnet: After booting, my local network can no longer be reached. I use the network interface ippp0 with ifconfig; the default route points to ippp0. <label id="trouble_nolocalnet"> <p> Wolfgang Barth wrote on 5 Jan 1997: <quote> I've noticed that after the first connection via ippp0 that the local network can again be reached. Then the address is no longer listed in ifconfig for ippp0, but instead the address assigned from the pool by the PPP partner. This was already discussed in de.comp.os.linux.networking, along this possible solution: Simply set ippp0 to a dummy IP number from the pool. Then the local network will have problems after booting, even with the default route, and the IP number in ifconfig will be overwritten anyway. </quote> <sect1> trouble_unauthorizedcodechange: When HiSax starts, I get the error messages 'Approval certification failed, unauthorized source code changes'? <label id="trouble_unauthorizedcodechange"> <p> Since the certification of the HiSax driver is only valid for unchanged source code, the source code is protected by a checksum. When you get this message, then either you have changed the source code yourself, or the author did not update the checksum when changing the source code (reason could be that the complete certification tests have not yet been run on the changed code). <sect1> trouble_crcerror: How can I see the number of packets for HiSax with invalid CRC? <label id="trouble_crcerror"> <p> With HiSax you can view the accumulated number of hardware CRC errors with: <code> hisaxctrl <id> 0 0 </code> and reset them with: <code> hisaxctrl <id> 0 99 </code> It is ok if you have the occasional CRC error, but if you see a lot of errors then check your cable termination & connectivity. <sect1> trouble_amproglibtool: When compiling isdn4k-utils I get the error 'AM_PROG_LIBTOOL not found'? <label id="trouble_amproglibtool"> <p> You have to regenerate the files from automake/autoconf with your version of automake/autoconf. You can do it with the following shell script (assuming you stored the source code for the isdn4k-utils under ~/isdn/isdn4k-util): <code> cd ~/isdn/isdn4k-utils for i in capi20 capiinfo capifax capiinit rcapid ; do cd $i rm -f lt* aclocal libtoolize --force --automake --copy automake --add-missing --copy autoconf cd .. done for i in eicon isdnlog ipppd ; do cd $i autoconf cd .. done </code> <!-- Config MSN --> <sect> msn: Configuration/MSNs <label id="msn"> <sect1> msn_my1: What is my MSN? What if I don't have any? <label id="msn_my1"> <p> Your telephone company will tell you your MSN. It is your own telephone number. Please note that you <bf/have/ to provide i4l with at least one MSN. If you don't have any you can use `0', which is assumed if no MSN is transmitted from your telephone company. Check section <ref id="countries" name="countries">, together with the following questions, on how to configure your MSN(s). <sect1> msn_my2: How can I find out how my telephone number is transmitted to the calling party? <label id="msn_my2"> <p> The transmitted MSN can simply be determined by calling yourself (for example by telephone). In the log files you will find the entry that looks like: &dquot;isdn_tty: call from XXX - YYY ignored&dquot; (in order for this to work, you must of course already have the ISDN drivers in your kernel and active). <sect1> msn_config: How do I configure my MSN? <label id="msn_config"> <p> If your telephone number were 56789, then it would be configured as follows: <itemize> <item>Modem emulation: <tt>&dquot;AT&e56789&dquot;</tt> <item>Network interfaces: <tt>&dquot;isdnctrl msn interface 56789&dquot;</tt> <item>For test calls to yourself add the area code (e.g. 01234): <code> &dquot;isdnctrl addphone interface in 123456789&dquot; (without leading zero) &dquot;isdnctrl addphone interface out 0123456789&dquot; (with leading zero) </code> </itemize> You may find national differences here (check section <ref id="countries" name="countries">). <sect1> msn_max: How many MSNs as a maximum can I use for an isdn card? <label id="msn_max"> <p> For outgoing calls, at maximum one MSN can be used. Only incoming calls may be configured to allow multiple MSNs. For ttyI* devices, at a maximum you can listen to EVERY incoming MSN by using the * as a wildcard: <code> at&l* </code> When you have a point-to-point connection you should rather specify the length of your number area with as many times &dquot;?&dquot; as you have digits, otherwise your number may be accepted too early on overlapping receiving. I.e. for 3 digits use: <code> at&l??? </code> For network devices, you can also use a '*' as a wildcard at the end of the number for incoming calls (e.g. <tt>isdnctrl msn interface 123*</tt>). However, this will create problems for outgoing calls. To handle such a situation properly, please use the isdnctrl mapping feature (see question <ref id="dialout_manycards" name="dialout_manycards">). <sect1> msn_mindialin: How can I minimize usage of MSNs for digital data dialin? <label id="msn_mindialin"> <p> i4l gives priority to net interfaces. Therefore, you can get away with only one MSN when you set it up like this: <enum> <item>Set up net interfaces (sync ppp, rawip) for all users that will want to use them (ipppd or rawip), with their incoming phone number (precondition is that it is transmitted). <item>Set up ttyI* for all other users (X.75, async ppp). <item>Set option `secure on'. </enum> i4l gives priority to net interfaces. `secure on' ensures that only users that have been set up will be connected to a net interface. Users that want to choose between both will have to use different outgoing MSNs to call you. <sect1> msn_onlyone: How can I use one MSN for everything? <label id="msn_onlyone"> <p> In Germany, this is not much of an issue any more since you can get 10 MSN for free with Deutsche Telekom (<url url="http://www.dtag.de/english/">). Other phone providers may offer less MSN for free. In general, you can get at least 3 MSN. However, minimizing MSN usage may still be very interesting for other countries or if you have a large demand for numbers. On a normal ISDN bus with MSNs, 10 MSN per bus are the maximum. To get more numbers, your only alternative would be to get a usually more expensive point-to-point ISDN connection. Digital data dialin can easily be distinguished from voice/analog modem dialin by the 'Service Recognition' code (&dquot;digital, data&dquot;). For the differentiation between net interfaces (ipppd, rawip) and ttyI* (X.75) see last question. To get voice/analog modem to work in parallel, use mgetty for the analog modem. Mgetty can handle analog data calls, faxes, and even voice calls as answering machine if the modem supports it. Configure it for 10 rings. If you take the phone and hear a fax or modem, send mgetty a USR1 signal (kill -USR1 mgetty-pid). If your phone socket is correctly wired, the modem will take over the connection, cutting off the phone. If you have an ISDN PBX then you can forward the call to a different analog port when you picked up a fax/modem call. If your analog modem can not handle voice calls, then you have to choose since incoming voice calls can not be distinguished from analog fax/data calls. Use either VBOX to take your voice calls as an answering machine. Or forget about voice calls and set up your modem to handle only faxes and/or analog data calls. <sect1> msn_buendel: Can I have several NTBAs, all with the same MSN? <label id="msn_buendel"> <p> Yes, but you need the cooperation of your telecommunication company. They can set up several BRIs in Point-to-point mode that have the same MSN. In Germany it is called a bundled line (`Bündelanschluß'). Please note that in such a case the MSN may not be transmitted to you. Just use the default MSN 0 then. <sect> lan: ISDN4LINUX in a LAN <label id="lan"> <sect1> lan_config: How can I set up Linux so that other computers in my LAN can access the internet via my Linux computer? <label id="lan_config"> <p> There are several possibilities: <enum> <item>Your LAN is an official Class C net with IP addresses valid on the Internet. This case is the easiest of configure. You give each network card on your network one of these addresses and set a default route on the ISDN card that goes to your provider. <item>You'd only like to do http in Internet from your LAN. In this case you can make up IP addresses for your LAN; the only official IP address is that for your ISDN card. Then install a proxy server on your Linux router, and enter it in all of your browsers. In this case you do not need a default route. <item>From your LAN you only want to log in to your Linux ISDN router and FROM THERE do your work on the Internet. This is even simpler, then you don't even need a proxy server. <item>Use ip masquerading. This is the most comfortable one to use, but more difficult to set up. The Linux computer acts as a gateway. The trick is that it hides the ip addresses of the LAN, by giving its own internet address as response address. When receiving the response, it will forward it to the correct computer on the LAN. You can also use masquerading with dynamic ip addresses. If you don't want to start the ISDN connection from the Linux computer to your internet provider manually, then you can set up dial on demand functionality (see section <ref id="dod" name="dod">). </enum> <sect1> lan_modemserver: How can I allow the users in my LAN to dial out via the ISDN card(s) in my Linux PC (like a modem server)? <label id="lan_modemserver"> <p> On the Linux side use modemd, which is a very short perl script (also see Linux Modem sharing mini-HOWTO at <tt><url url="http://www.linuxdoc.org/HOWTO/mini/Linux-Modem-Sharing.html"></tt>): <code> #!/usr/bin/perl select((select(STDOUT), $| = 1)[$[]); select((select(STDIN), $| = 1)[$[]); exec &dquot;cu&dquot;,&dquot;-E&dquot;,&dquot;''&dquot;, &dquot;-l&dquot;, &dquot;$ARGV[0]&dquot;; die &dquot;$0: Cannot exec cu: $!\n&dquot;; </code> It has to be started by inetd, therefore this has to be added to <tt>/etc/services</tt>: <code> modem 20006/tcp modemd # Modem service via TCP isdn 20007/tcp modemd # ISDN service via TCP </code> And this has to be added to <tt>/etc/inet.conf</tt>: <code> modemd stream tcp nowait root /usr/sbin/tcpd /usr/sbin/modemd ttyI5 </code> Instead of modemd you can also use the program mserver, which has some additional functionality (e.g. rights based on ip address): <tt><url url="ftp://ftp.innet.be/pub/staff/carl/"></tt> Additionally, you need some software on your non-ISDN computer which emulates a serial port, but redirects it via telnet to the Linux ISDN computer. Some telnet clients allow this functionality (e.g. some uucicos). If you generally want to offer all applications a kind of &dquot;remote COM port&dquot;, then there is COMT for Windows (95), and &dquot;telser.device&dquot; for Amigas. Disadvantage of COMT: it is only visible to ancient 16bit Win applications, and not even working in the DOS box. Another program is DialOut/IP, but it's fairly expensive ($70). COMT may be found on Simtel: <tt><url url="http://educom.sce.fct.unl.pt/ftp/pub/shareware/win-utils/comt2.zip"></tt> DialOut/IP can be found on: <tt><url url="http://tacticalsoftware.com"></tt> Those who just want to save their CrossPoint installation should be aware that it now offers tcp modem support, such that it will run without additional software. Check out: <tt><url url="http://www.openxp.de"></tt> <!-- Dialout --> <sect> dialout: Configuration of Dial-Out <label id="dialout"> <sect1> dialout_config: How do I configure dialout properly? <label id="dialout_config"> <p> First you have to decide on how you want to dial out. You will have to use whatever your counterpart requires. These are your main options: <itemize> <item> Sync PPP: This is what most Internet Service Provider expect from you. See section <ref id="syncppp" name="syncppp">. <item> Async PPP: May also be handled by your Internet Service Provider. Use when Sync PPP does not work for you. See section <ref id="asyncppp" name="asyncppp">. <item> Raw IP: Most efficient for TCP/IP over ISDN. It has very quick dialouts, but is not as common. See section <ref id="rawip" name="rawip">. <item> X.75: This is what you need to dial into an ISDN mailbox. See section <ref id="ttyI" name="ttyI">. <item> Leased line: For this special case, see section <ref id="leased" name="leased">. </itemize> Have a look on section <ref id="dod" name="dod"> on how to configure dial on demand - and on the dangers attached to it. For more advanced dialout features see question <ref id="dialout_advanced" name="dialout_advanced">. Also you may have a look at section <ref id="remote" name="remote"> when you try to connect to a special remote ISDN device. <sect1> dialout_dialmode: When an IP packet should go over the link (which usually triggers a dialout), all I see in the log is: &dquot;dial rejected: interface not in dialmode <tt/auto/&dquot;? <label id="dialout_dialmode"> <p> The new ISDN drivers in 2.0.36 defaults to manual dialmode, not autodial. This is done to prevent unexpected (and unnoticed) dialouts. (See the big section about those and their dangers: <ref id="dod" name="dod">). To enable autodial for a given interface e.g. ippp0, use <code>isdnctrl dialmode ippp0 auto</code> The meaning of the values for dialmode is: <descrip> <tag/off/ means that you (or the system) cannot make any connection (neither incoming nor outgoing connections are possible). Use this if you want to be sure that no connections will be made. <tag/auto/ means that the interface is in auto-dial mode, and will attempt to make a connection whenever a network data packet needs the interface's link. Note that this can cause unexpected dialouts, and lead to a high phone bill! Some daemons or other pc's that use this interface can cause this. Incoming connections are also possible. <tag/manual/ (DEFAULT) is a dial mode created to prevent the unexpected dialouts. In this mode, the interface will never make any connections on its own. You must explicitly initiate a connection with: <code>isdnctrl dial ippp0</code> To end the connection, use: <code>isdnctrl hangup ippp0</code> Please note that the <tt/huptimeout/ may still end the connection automatically! To ensure that you have to hang up manually, you have to switch this off: <code>isdnctrl huptimeout ippp0 0</code> </descrip> To allow a normal user to initiate a dialout, have a look at question <ref id="dialout_permission" name="dialout_permission">. <sect1> dialout_advanced: What special dialout features are available? <label id="dialout_advanced"> <p> Check out these special dialout features: <itemize> <item> Save money by hanging up just before a charge unit: see section <ref id="chargeint" name="chargeint">. <item> Dialout on more than 1 channel at the same time: see section <ref id="2channel" name="2channel">. <item> Dialout on one specific channel: see question <ref id="dialout_fixedchannel" name="dialout_fixedchannel">. <item> Callback: see section <ref id="callback" name="callback">. </itemize> <sect1> dialout_permission: How can I allow a normal user to initiate dialouts? <label id="dialout_permission"> <p> ISDN usage depends on the permissions to the devices <tt>/dev/ttyI*</tt> and <tt>/dev/cui*</tt>. You have several choices to selectively allow users to do ISDN transactions. <enum> <item>You can establish the group `isdn' in <tt>/etc/group</tt>, and do: <code> chgrp isdn /dev/ttyI* /dev/cui* chmod o-rw /dev/ttyI* /dev/cui* </code> It has been reported that you also may have to change group and permissions on the programs <tt/ipppd/ and <tt/isdnctrl/ to 'isdn'. Then all users not in the group 'isdn' have no reading or writing privileges for the ISDN ttys. Those allowed to use ISDN have to be explicitly added to the group 'isdn'. <item>You can allow only root to log out, but set up exceptions for other users with the su1 functionality (see man su1). As root edit <tt>/etc/su1.priv</tt>. Add these lines if they (or similar ones) are not yet there, to allow users XXXX and YYYY to initiate dialups/hangups: <code> # log all dialouts in syslog syslog all define PPPUSER XXXX YYYY alias dial /sbin/isdnctrl dial ippp0 alias hangup /sbin/isdnctrl hangup ippp0 ask never allow PPPUSER prefix dial allow PPPUSER prefix hangup </code> Then create two links for dial and hangup: <code> ln -s /usr/bin/su1 /usr/local/bin/dial ln -s /usr/bin/su1 /usr/local/bin/hangup </code> Now the users XXXX and YYYY can dial out by typing <tt/dial/, and hangup with <tt/hangup/. <item>If you only have one user that you use for ISDN interactions, you can make him owner of the ISDN interface. </enum> <sect1> dialout_manycards: How do I configure dialout with more than 1 ISDN card? <label id="dialout_manycards"> <p> There are several possibilities to configure dialout. <itemize> <item>Dialout anywhere (default: all available cards are a pool, dialout on one MSN): just configure your cards in the order in which you want them to be dialed out. First all channels on the first card are used, then all on the second card, and so on. Please note that the net interface or ttyI device will try to dial out using the MSN it was configured for - on all cards. Even on those that do not have this MSN! In such a case, the telco will replace that invalid MSN with the correct one. Use <tt/isdnctrl mapping/ to configure the correct MSNs (see item 'dialout on one specific card'). <item>Dialout on one specific channel: Use the <tt/isdnctrl bind/ (not pppbind) command to specify which channel should be used. Please use this command after all other configuration with isdnctrl has been done! Check with <tt/isdnctrl list/ that the binding actually works. <item> Dialout with different MSN on each card: You can configure this by using the <tt/isdnctrl mappping/ functionality. Just map MSNs on the letters 0 to 9, like this: <code> isdnctrl mapping <carddriver1> 111,222,333,, isdnctrl mapping <carddriver2> 999,888,,777 </code> Now, you could configure for telephone number 0 when you really want to use MSN 111 on <carddriver1> or 999 on <carddriver2> (however, since 0 has a special meaning, try to avoid using number 0). Configure to use number 1 when you really want to use MSN 222 on <carddriver1> or 888 on <carddriver2>. Configure to use telephone number 2 when you really want to use only MSN 333 on <carddriver1> (<carddriver2> will use the default MSN when used). Configure to use telephone number 3 when you really want to use only MSN 777 on <carddriver2> (<carddriver1> will use the default MSN when used). <item>Dialout on one specific card: After installing a patch that was posted by Karsten Keil on the mailing list against 2.2.12, you can disallow calls on some cards by using the <tt/isdnctrl mapping/ functionality. <code> isdnctrl mapping <carddriver1> 111,222,333,-, isdnctrl mapping <carddriver2> 999,888,-,777 </code> It works as discribed for "Dialout with different MSN on each card", except that the "-" means dialing is disallowed. Dialout on telephone number 2 will now only dial out with MSN 333 on <carddriver1>, while dialout on 3 will now only dial out with MSN 777 on <carddriver2>. </itemize> <sect1> dialout_fixedchannel: How can I force HiSax to always dial out on a specific B channel? <label id="dialout_fixedchannel"> <p> HiSax has an undocumented feature for this. Add 'P1' in front of the dialout phone number for the first B channel, or 'P2' for the second B channel, like this: <code> isdnctrl addphone <device> out P1<your_out_number> </code> This will indicate the preferred B channel in the outgoing SETUP message. Please note that some PBX may not like this. Obviously, a dialout will fail when another device already uses the second B channel. <sect1> dialout_dynip: On dynamic ip assignment, how do I find out which ip address is being used for dialout? <label id="dialout_dynip"> <p> Create a script called <tt>ip-up</tt>. It will be called by the ipppd whenever the connection is established with several parameters. The ip address is passed in as the fourth parameter (access it as <tt>$4</tt>). <sect1> dialout_bind: A dns query causes bind to dial out. Why does it take about a minute before it is answered? How do I work around it? <label id="dialout_bind"> <p> You are probably using the name server in 'forward' mode, and your ISP works with dynamic ip addresses. The initial UDP query will be lost since it carries the wrong source address. Unfortunately, bind will wait a whole minute before retransmitting the query again if you have only one forwarder. As a workaround, you can enter 4 times the same forwarder in named.conf to adjust retransmission timing (in 'forward' mode, bind retransmits its queries after the following period of time: 60 seconds divided by the number of nameservers given in the section "forwarders" of named.conf). <code> forwarders {;;;; } </code> Bind will then retransmit the query every 15 seconds to your forwarder (here the forwarder is The same principle applies to two or more forwarders. Another option are the programs <tt/ip_resend/ and <tt/ip_resend_wakeup/ which you can find on: <url url="http://www.baty.hanse.de/ip_resend/"> <!-- Authenticate properly --> <sect> pap: Authenticate properly (especially with PAP) <label id="pap"> <sect1> pap_optionauth: When dialing out, I get the message &dquot;pppd: peer authentication required but no authentication files accessible.&dquot; What does this mean? <label id="pap_optionauth"> <p> Most likely the option &dquot;auth&dquot; was set by mistake. Then the <em>other</em> side is required to be authorized. <sect1> pap_requestauth: I cannot establish a connection - it's rejected by the other side. In the log file I find a message that's something like: &dquot;sent (0) (LCP ConfReq id=0x1 mru 1500 auth pap magic 0xcd12e9c4&dquot; <label id="pap_requestauth"> <p> Like in the last question, an option has been set that requires the <em>other</em> side to be authorized. These options shouldn't be set. Possible candidates are: &dquot;+pap&dquot; as well as &dquot;+chap&dquot;. <sect1> pap_rejectauth: I cannot establish a connection - it's rejected by the other side. In the log file I find a message that's something like: &dquot;sent (0) (LCP ConfRej id=0x1 auth pap&dquot; <label id="pap_rejectauth"> <p> Your computer is refusing to identify itself with user name (e.g. XXX) and password (e.g. YYY). That only works with the authorization options &dquot;user XXX&dquot; and &dquot;remotename YYY&dquot; for ipppd or pppd together with a correct (!) /etc/ppp/pap-secrets. With a password of ZZZ it should ideally look like this: <code> XXX YYY ZZZ * </code> If you have special characters in XXX, YYY, or ZZZ, try to use quotes around them. If that doesn't work for getting XXX or YYY correct, you can use wild cards, something like: <code> * * ZZZ * </code> Then <em>every</em> partner has the password ZZZ. If chap is required for authorization, then /etc/ppp/chap-secrets must be set up correctly. Important: the format is different from that of pap-secrets! One important point is to use only the tabulator instead of space to separate username, computer, password. Make sure to consult the README's, or check out: <tt><url url="http://www.lrz-muenchen.de/˜ui161ab/www/isdn/"></tt> Also have a look at the next question: <ref id="pap_passwd" name="pap_passwd">. <sect1> pap_checkpwd: How can I check which password is actually sent to the remote side? <label id="pap_checkpwd"> <p> Use the options <tt/debug/ and <tt/+pwlog/ for ipppd or pppd. Then you can see your password in the log file. <sect1> pap_passwd: I have problems with PAP or CHAP authentication. It does not work although I'm sure I entered passwords etc. correctly. <label id="pap_passwd"> <p> Stefan A. Muehlenweg <tt><htmlurl url="mailto:Stefan.A.Muehlenweg@samhh.hanse.de" name="Stefan.A.Muehlenweg@samhh.hanse.de"></tt> wrote on 4 Oct 1996: <quote> I had exactly the same problem/the same error message. The cause for it was that I had three entries in chap-secrets/pap-secrets (for client, server, secret), but not a fourth one (IP addresses). BUT: after the third entry were some BLANKs. After removing the trailing BLANKs and/or TABs (i)pppd is now very satisfied with my auth-files. </quote> A further source of problems can be the password itself. If it contains the &dquot;#&dquot; character, then everything after than is understood as a comment. Spaces or tabs can cause similar problems. Solution: put the password in quotes! <!-- Config Sync PPP --> <sect> syncppp: Sync PPP <label id="syncppp"> <sect1> syncppp_whichppp: pppd, ipppd, syncPPP, asyncPPP .. what is they? Which should I use? <label id="syncppp_whichppp"> <p> See this question in the <em/asnyc PPP/; section: <ref id="asyncppp_whichppp" name="asyncppp_whichppp">. <sect1> syncppp_compile: How do I compile isdn4linux with syncPPP? <label id="syncppp_compile"> <p> To compile the kernel with syncPPP included in ISDN4Linux, you have to answer the appropriate questions with &dquot;yes&dquot;. Don't forget to load the module slhc.o before isdn.o, if VJ compression is not compiled into the kernel e.g. if you have no PPP and no CSLIP in the kernel. (Note that the use of VJ is problematic for elder kernels and does not work reliably - however, the support should still be included in the kernel, since there can otherwise be side effects.) <sect1> syncppp_netinterface: How should I name my network interface? <label id="syncppp_netinterface"> <p> The name of the network interface should <em>always</em> begin with &dquot;ippp&dquot;, <em>not</em> with &dquot;syncppp&dquot; or &dquot;isdn&dquot;; otherwise the communication with ipppd will not work correctly. Please note that at least one of the interfaces has to be &dquot;ippp0&dquot;, otherwise ipppd will not start. Check your interfaces with the command <tt>ifconfig</tt>. <sect1> syncppp_config: How do I configure isdn4linux with syncPPP? <label id="syncppp_config"> <p> Synchronous PPP is simply another encapsulation for ISDN4Linux. This encapsulation is called &dquot;syncppp&dquot;. Here is an example to configure the link level device ippp0: <code> /sbin/isdnctrl addif ippp0 /sbin/isdnctrl encap ippp0 syncppp </code> Please note that syncppp is very peculiar about the names of the device. Only devices starting with &dquot;ippp&dquot; will work, at least one interface has to be named ippp0 (see question <ref id="syncppp_netinterface" name="syncppp_netinterface"> for details). All ippp* devices in use must be configured separately. Each ippp* device should be assigned to its own IP address (routing!). Several ippp* devices can be assigned to a single MSN. Several callers can then simultaneously use this MSN. To use these devices you need the program <tt/ipppd/, which you have to configure. You have to start ipppd once after the modules are installed. ipppd needs to be constantly running to allow dialout/dialin. It communicates with the isdn4linux link level devices through <tt>/dev/ippp0</tt> to <tt>/dev/ippp63</tt>. A single ipppd can handle all devices at once. If you want two PPP connections at the same time, you need to bind ipppd to two devices, etc. As a result, <tt/ipppd/ provides the network device <tt>ippp0</tt>, which can be checked with ifconfig (even so it has the same name, the network device <tt/ippp0/ is not to be confused with <tt>/dev/ippp0</tt> which is used for communication between ipppd and link level. ipppd has an additional option: &dquot;useifip&dquot; uses the IP address of the connected network interface (if it is not (Even then, ipppd tries to use the pointopoint address as the remote IP.) For the beginning, disable all compression (lzs/stac, bsd, van jacobson), later you can try to enable it (see question <ref id="syncppp_compression" name="syncppp_compression">). It is very important to set up the authentication information properly. Improper authentication is probably the most frequently reported problem on the mailing list. Please, work through section <ref id="pap" name="pap"> completely yourself, before asking others for help. You can find an example configuration in the file <tt>etc/rc.isdn.syncppp</tt> in the isdn4kernel-util package. You can also run several ipppds to allow for different configurations, in such a case use the <tt>&dquot;isdnctrl pppbind"</tt> functionality. However, normally one ipppd is meant to handle all traffic, so it is highly recommended to only set up several ipppds if their configuration has to be different. <sect1> syncppp_busy: How can I tell if a connection is unsuccessful (busy)? <label id="syncppp_busy"> <p> When giving the option <tt/defaultroute/, then you can wait a few seconds, then check whether the default route exists. Another way, when giving option <tt>useifip</tt> is to check whether you find entries like <tt>&dquot;Local IP: x.y.z.a&dquot;</tt> and/or <tt>&dquot;Remote IP: x.y.z.a&dquot;</tt> in syslog. In either case, the connection is up. <sect1> syncppp_logindelay: How can I reduce login delay? <label id="syncppp_logindelay"> <p> You can write out a login session with (&dquot;Debug-Log&dquot;), and see which options the other computer is refusing. Next time, configure ipppd without these unused options. A further side effect is that such unused options increase the redundance (e.g. when the other computer has bugs and refuses the options incorrectly). To create a log file, see &dquot;How to I create a log for ipppd&dquot;. <sect1> syncppp_2configs: I want to talk to remote machines which needs different configurations. The only way I found to do this is to kill the ipppd and start a new one with another config to connect to the second machine. <label id="syncppp_2configs"> <p> You must bind a network interface explicitly to an ippp device, where you can connect a (for this interface) individually configured ipppd. With the (unfortunately poorly documented) command <code> isdnctrl pppbind interface Number </code> you can link the interface interface to the device ipppNummer. You can release the link with &dquot;pppunbind&dquot;. <sect1> syncppp_pppbind: How does the (little-documented) &dquot;pppbind&dquot; command in isdnctrl work? <label id="syncppp_pppbind"> <p> You have to first know how ipppd gets its data. All data that come in over the ISDN line is received by the network devices (these are set up with isdnctrl). Then the data given to one of the /dev/ippp* devices - to one where a ipppd daemon is waiting for data. To the network interfaces, all ipppd's appear to be able to handle the just-received data - therefore it is normally impossible to predict which ipppd will receive data from which network interface. In practice, you usually install several ipppd's with differing configurations. Each of these should receive data <em>exclusively</em> from a certain network interface (that has also be specially configured). The &dquot;pppdbind&dquot; command serves just this purpose. With: <code> &dquot;isdnctrl pppbind interface number&dquot; </code> attaches the interface interface to the device /dev/ipppnumber. Example: To attach the interface &dquot;ippp5&dquot; to /dev/ippp2, the following configuration should be used: <code> &dquot;isdnctrl pppbind ippp5 2&dquot; </code> Similarly, the command &dquot;pppunbind&dquot; will undo this attachment. <sect1> syncppp_dynip: I want to use dynamic IP address assignment. How must I configure the network device? <label id="syncppp_dynip"> <p> At least you must have a route, which forwards a packet to the ippp network interface to trigger dialing. A default route to the ippp interface will work. Now you must choose a dummy IP address for your interface. If for some reason you can't set the default route to the ippp interface, you may take any address of the subnet from which you expect your dynamic IP number and set a 'network route' for this subnet to the ippp interface. To allow overriding of the dummy address you must call the ipppd with the 'ipcp-accept-local' option. You must know how the ipppd gets the addresses it has to configure. If you don't give any option, the ipppd tries to negotiate the local host address! With the option 'noipdefault' it requests an address from the remote machine. With 'useifip' it gets the addresses from the net interface. You also can set the addresses in the option line with the a.b.c.d:e.f.g.h option. Note: the IP address of the remote machine must be configured locally, or the remote machine must send it in an IPCP request. If your side doesn't know the IP address after negotiation, it will close the connection! You must allow overriding of addresses with the 'ipcp-accept-*' options, if you have set your own or the remote address explicitly. Try these options, e.g.: <code> /sbin/ipppd :$REMOTE noipdefault /dev/ippp0 </code> where REMOTE must be the address of the remote machine (the machine giving your address to you) <sect1> syncppp_msgetdns: How do I configure ipppd to obtain or provide the nameserver address at dial in? <label id="syncppp_msgetdns"> <p> Use the configuration option <tt/ms-get-dns/ to obtain the nameserver ip address when you dial up your internet provider. Use <tt/ms-dns/ to publish the nameserver ip address when someone dials up your ipppd. <sect1> syncppp_ipx: How can I do IPX over ipppd? <label id="syncppp_ipx"> <p> Give the option <tt/+ipx-protocol/ to the ipppd. <sect1> syncppp_faster: How can I increase my PPP data transfer rates? <label id="syncppp_faster"> <p> You can establish more channels with MPPP (see the MPPP section). Another way is to use compression, see question <ref id="syncppp_compression" name="syncppp_compression">. <sect1> syncppp_compression: Which compressions can I use with ipppd? <label id="syncppp_compression"> <p> Several compressions can now be used with ipppd. However, if in doubt and it does not work: disable it. <itemize> <item><em>Van Jacobson compression</em> (header compression). Should work fine now for current kernels (later than 2.2.14). To use it you have to compile it into the kernel. To get around some problems with automatic loading of the VJ module try to also compile SLIP and CSLIP into the kernel. Disable with options <tt>&dquot;-vj -vjccomp&dquot;</tt>. <item><em>BSD compression</em>. Seems to work quite well if your peer supports it. It is independent of Van Jacobson compression, so you can use them both together. <item><em>LZS compression</em> (sometimes also called <em>Stac compression</em>). Also works quite well. To enable it, some manual work has to be done to add the code to the ipppd (see the isdn4k-util package). </itemize> <!-- Trouble ipppd --> <sect1> syncppp_strategy: I can't get a connect. How can I find out where the problem is? <label id="syncppp_strategy"> <p> The output of ipppd is very helpful... (see next question: <ref id="syncppp_log" name="syncppp_log">) <itemize> <item>Have a look at the error messages and see the following questions... <item>Check whether you can find a few &dquot;LCP-conf-req SENT&dquot; messages (less than ten) and then a &dquot;TERM-REF&dquot;. <item>Check whether the ISDN card was configured properly. It seems the computer doesn't dial (IRQ, IO, protocol wrong?) <item>At least a few &dquot;RECV&dquot; messages: good! The card is dialing and your dialin computer tries to communicate. Maybe the pap/chap authentication doesn't work (see question <ref id="pap" name="pap">). Check the ipppd configuration! <item>The message that ipppd was exited for some reason: not so good! Check <tt>/var/log/messages</tt>, <tt>/var/log/debug</tt>, and <tt>/var/adm/daemon</tt> (if existing). Could be a bug in ipppd. <item>The error/cause E0010 is <bf/NOT/ an error! It is just the informal message that the call has ended. </itemize> <sect1> syncppp_log: How can I get a log for ipppd? <label id="syncppp_log"> <p> Normally when giving the option "debug" to ipppd, the debbuging output may be logged in <tt>/var/log/messages</tt>, <tt>/var/log/debug</tt>, or <tt>/var/adm/daemon</tt> (depends on your distribution, look around). For debugging purposes you can redirect the PPP log into a separate file. Just edit <tt>/etc/syslog.conf</tt> and add the following line (caution: do NOT use blanks or tabs - check "man syslog.conf(5)" for more details): <code> daemon.* /var/log/ppp-log </code> then every information from PPP demon will be logged to /var/log/ppp-log. Emil Stephan <tt><htmlurl url="mailto:ste@esqhen.su.eunet.de" name="ste@esqhen.su.eunet.de"></tt> also wrote: <verb> Remove the comment sign in front of this line in /etc/syslog.conf: #*.=debug /tmp/debug After changing this file you can restart syslogd with &dquot;kill -1 pid of syslogd&dquot;. The output in /tmp/debug can be used to optimize the handshaking of PPP options. </verb> <sect1> syncppp_nopppsupport: Starting ipppd I get the error message &dquot;this systems lacks ppp support&dquot; or &dquot;isdn driver is out of date. maybe ippp0 has no syncppp0 encapsulation&dquot;. <label id="syncppp_nopppsupport"> <p> Check whether the device &dquot;ippp0&dquot; exists (i.e. with the program &dquot;ifconfig&dquot;). See question <ref id="syncppp_netinterface" name="syncppp_netinterface"> for details on the naming conventions for net interfaces. The ipppd *needs* this device with exactly *that* name and *syncppp* encapsulation. If it doesn't exist then you have to define it: <code> isdnctrl addif ippp0 isdnctrl encap ippp0 syncppp (see i4l documentation or question <ref id="syncppp_config" name="syncppp_config"> for more information...) </code> Maybe you compiled ipppd with the source of another kernel that you are not using... <sect1> syncppp_nousabledevice: When I try to start ipppd it says &dquot;Can't find usable ippp device&dquot; <label id="syncppp_nousabledevice"> <p> This message occurs when the linklevel interface is told to dial out, but ipppd is not running, or not available. <sect1> syncppp_starterror: When I start ipppd, I only get error messages from the i4l driver. <label id="syncppp_starterror"> <p> When ipppd is started, it calls functions that can trigger a network packet (e.g. gethostbyname()). Without ipppd (since at this time, ipppd it has not been fully started), this network access cannot be processed, You should try to put the needed hostnames in the local /etc/hosts or in some way define the name so that it can be resolved without having the access the ISDN/ippp interface. <sect1> syncppp_framesdelayed: I get the message <tt>IP frames delayed</tt> - but no connection. <label id="syncppp_framesdelayed"> <p> Have you really dialed out? Check question <ref id="dialout_dialmode" name="dialout_dialmode"> and your configuration on the different dialmodes. <sect1> syncppp_noroute: I cannot dial out with <tt>isdnctrl dial ippp0</tt>. It seems as if the route to ipppd is missing although I <bf/did/ set it (<tt>network unreachable</tt>). With my old kernel 2.0 everything works fine! <label id="syncppp_noroute"> <p> In the newer kernels you have to place <tt>route</tt> as the very last command before the dialout command. Otherwise the kernel will delete the route. <sect1> syncppp_nodefaultroute: After ipppd dials out my default route is gone. <label id="syncppp_nodefaultroute"> <p> It's the kernel's fault. Newer kernels (= 2.0.x) have some changes in the routing. Workaround: install a script /etc/ppp/ip-up like this: <code> #!/bin/sh /sbin/route add default ippp* </code> Please note, that for 2.2.x kernel, you should NOT do this (routing has changed yet again). Instead, give the "defaultroute" option to ipppd. If you make your connections manually, can use something like this script: <code> /sbin/isdn #! /bin/sh case $1 in on) /sbin/isdnctrl dial ippp0 # build up connection sleep 5 # wait until line open /sbin/route add default ippp0 # set route ;; off) /sbin/isdnctrl hangup ippp0 # hangup connection /sbin/route del default # and delete route again ;; *) echo -e &dquot;\a Usage: 'isdn on' or 'isdn off'&dquot; ;; esac </code> Please note, that for 2.2.x kernel, you should NOT use the <tt>route add default</tt>, and <tt>route del default</tt> commands. Instead, give the "defaultroute" option to ipppd. <sect1> syncppp_packettoolarge: I often get the error message <tt>hscx_empty_fifo: incoming packet too large</tt> <label id="syncppp_packettoolarge"> <p> Probably one of the compressions is activated (i4l can't handle those very well). See also next question. Another possible reason could be an IRQ problem - see question &dquot;Why should I avoid IRQ 12 and 15 for my ISDN card?&dquot;. Another problem can be `#' characters in your pap-secrets file. In this case you have to surround user name and/or password with quotation marks (depending on which one is affected). <sect1> syncppp_slow: The connection with ipppd seems to work, but eventually it crashes or is very slow. <label id="syncppp_slow"> <p> It could be that some compression is activated (that i4l can't handle properly). Common error: &dquot;-vj&dquot; has to be used *additionally* to &dquot;-vjccomp&dquot; (to completely switch off the VJ compression) - the example scripts coming with ipppd don't have that option included already. Other compression modes (bsd, pccomp) can cause trouble, too. Therefore, you should switch off all compression options (see also question <ref id="syncppp_compression" name="syncppp_compression">). Also giving the option &dquot;noccp&dquot; can help. <sect1> syncppp_loadproblem: I only have problems with ipppd when the connection is being heavily burdened. Then everything stops. What could be causing this? <label id="syncppp_loadproblem"> <p> Sven Engelhardt <tt><htmlurl url="mailto:sven@sik.de" name="sven@sik.de"></tt> wrote on 12 Dec 1996: <quote> We are an ISP here in Dresden and use Linux (among other systems) for our access (with I4L as well as with external terminal adapters). We have this problem mostly with Windows 95 and NT customers who are using the &dquot;included&dquot; (modem network) software. It doesn't make any difference whether the customer is dialing with async or sync PPP. It also doesn't matter which modem emulation he is using on his side. What they have in common is that the connection is made with Microsoft modem adapter + Microsoft PPP (although a colleague recently told me about a similar problem with a Macintosh customer). Since it doesn't matter to PPP who is the server and who is the client, ask your ISP what kind of hardware you are dialing into (we have had no problems with Linux customers and Trumpet Winsock users, therefore I suspect a bug in MS-PPP). The following workaround usually works for us: (it's not a cure, but helps to reduce the pain...) * Reduce the Max MTU to 576 or even (296) * Reduce the DefaultRcvWindow to 2144 On the Windows 95 side these are 2 Registry entries; on the Linux side you can set &dquot;mtu 576&dquot; and &dquot;mru 576&dquot; in the PPP options. (See also: <tt><url url="http://www.winfiles.com/connect/trouble.html"></tt>) </quote> Erik Corry <tt><htmlurl url="mailto:ec@sign-tronic.dk" name="ec@sign-tronic.dk"></tt> added on 16 Dec 1996: <quote> For me, neither PPP compression option nor mru/mtu 296 helped. What did help was the AT command: AT&B512 that limits the sent packets to 512 bytes. </quote> <sect1> syncppp_mtu: My ipppd works, but I keep getting the message pppd(104): ioctl(SIOCSIFMTU): Invalid argument&dquot;? <label id="syncppp_mtu"> <p> If mtu is not set, then a default value is assumed - possibly &dquot;0&dquot; (which of course cannot be correct). Add <tt>&dquot;mtu 1024&dquot;</tt> to your ipppd options (1500 could also be ok). <sect1> syncppp_1stpacket: The first IP packet gets lost on automatic dialout with dynamic IP address allocation. <label id="syncppp_1stpacket"> <p> There are some dialout problems in connection with syncPPP and dynamic IP address allocation. In this case your IP address will change while packets are waiting to be sent. All packets that should be sent before the change in IP address have the wrong response ip address and will therefore never receive an answer. The problem is that this may cause multiple dialouts (see section <ref id="dod" name="dod">). Possible solutions: <itemize> <item>Dial out manually with &dquot;isdnctrl dial ippp*&dquot; <item>Use diald to control when the connection goes up or down. <item>Get a permanent IP address <item>A workaround is included in the newest kernels, which can be activated like this: <code> echo 7 > /proc/sys/net/ipv4/ip_dynaddr </code> (use 5 instad of 7 to not get warnings into /var/log/messages) If you have a SuSE distribution, this workaround can also be configured by setting <tt/IP_DYNIP=&dquot;yes&dquot;/ in <tt>/etc/rc.config</tt>. <item>Increase the number of retries on your Windows machine for setting up the connection. Change the registry entry <tt>Hkey_Local_Machine\\System\\CurrentControlSet\\Services\\VxD\\MSTCP\\MaxConnectRetries</tt> from 3 to a larger value (e.g. 5 or 7). </itemize> <sect1> syncppp_droppacket: What does the message &dquot;No phone number, packet dropped&dquot; mean? <label id="syncppp_droppacket"> <p> Michael Engert <tt><htmlurl url="mailto:michi@bello.wor.de" name="michi@bello.wor.de"></tt> wrote in Nov/Dec 1996: That means that your computer has an IP packet from somewhat who was logged on a few seconds before, but has since broken the connection. Your computer tries to send this packet on and finds an appropriate route. But the interface isdn(0|1|...) can't reach the other computer, since it has no telephone number to dial. <sect1> syncppp_leadingzero: Why does my ipppd dial one too many zeros (<tt>&dquot;ippp0: dialing 0 089XXXXXX...&dquot;</tt>)? I don't have any extensions! <label id="syncppp_leadingzero"> <p> The first zero is not dialed. It only shows the retry counter, which is related to the <tt/isdnctrl dialmax/ parameter. <sect1> syncppp_ethfake: My ISDN device is shown with HWaddr and IRQ=0 and base address = 0 when I list it with ifconfig <label id="syncppp_ethfake"> <p> The ISDN device fakes an Ethernet device. It ignores IRQ and baseaddr and just needs the HWaddr for the Ethernet encapsulation. <sect1> syncppp_lzsproblem: I get an error message like <tt>kernel check for lzs failed</tt>? <label id="syncppp_lzsproblem"> <p> This means that ipppd tries to use lzs compression, but can't find a compiled module which contains the code. The error message is only cosmetic, since the system will still work fine. Either disable lzs compression by providing <tt>noccp</tt> as an option for ipppd, or compile and load the lzs module. <!-- Config Async PPP --> <sect> asyncppp: Configuration Async PPP <label id="asyncppp"> <sect1> asyncppp_whichppp: pppd, ipppd, async PPP, sync PPP - what are they? Which should I use? <label id="asyncppp_whichppp"> <p> <bf>async PPP</bf> is a character-based protocol which is usually used over analog serial lines (async = asynchronous). You have to use the program <tt/pppd/ for it, and use it with the ttyI* devices. In contrast, <bf>Sync PPP</bf> is a bit-oriented protocol (sync = synchronous), for which the original <tt/pppd/ cannot be used. Michael Hipp has written an adapted version called <tt/ipppd/ which will use ipppd* net devices. With i4l you can have both. It all depends on what your ISDN counterpart supports. If it immediately begins to send frames, then you've probably reached an sync PPP machine. If you can log in via same terminal screen, and then can start <tt/pppd/, this can be an indication of async PPP. Usually using <bf/sync PPP/ works fine, and it is slightly more efficient. To take advantage of newer features of the <tt/pppd/, use <bf/async PPP/. <sect1> asyncppp_config: How do I configure async PPP? <label id="asyncppp_config"> <p> Just set up a normal pppd, but tell it to use one of the ttyI* devices, e.g. /dev/ttyI0. You can set up several pppd's with different configuration on different ttyI* devices. It is very important to set up the authentication information properly. Improper authentication is probably the most frequently reported problem on the mailing list. Please, work through section <ref id="pap" name="pap"> completely yourself, before asking others for help. On problems also check out the section about the syncppp problems, since many configuration problems are common for pppd (async PPP) and ipppd (sync PPP). <sect1> asyncppp_logindelay: How can I reduce login delay? <label id="asyncppp_logindelay"> <p> You can write out a login session with (&dquot;Debug-Log&dquot;), and see which options the other computer is refusing. Next time, configure ipppd without these unused options. A further side effect is that such unused options increase the redundance (e.g. when the other computer has bugs and refuses the options incorrectly). To create a log file, see &dquot;How to I create a log for ipppd&dquot;. <sect1> asyncppp_fast: How can I increase my transfer rates with PPP? <label id="asyncppp_fast"> <p> You can add more channels with MPPP (see question <ref id="2channel_mppp" name="2channel_mppp">). For everyone for whom that's to expensive and who use <em>async PPP</em>, there's a little trick. With the option &dquot;asyncmap 0&dquot; you can avoid escaping all control characters (ASCII32). If the other side goes along with this, you can increase the transfer rate by about 12%. <sect1> asyncppp_log: How can I get a log for pppd? <label id="asyncppp_log"> <p> See this question for Sync PPP, it works the same way for pppd. <sect1> asyncppp_suddendeath: Establishing the connection works fine, but pppd crashes just after that (i.e. the first bytes gets through, but then everything stops) <label id="asyncppp_suddendeath"> <p> This is probably due to an incorrect block size on your side. Initialize your ttyI* device with <tt/AT&B512/ or even smaller block sizes. <!-- Raw IP --> <sect> rawip: Raw IP <label id="rawip"> <sect1> rawip_whatis: What is Raw IP, when should I use it? <label id="rawip_whatis"> <p> Raw IP does without the use of a protocol such as X.75 or HDLC (for modem emulation, etc.) or PPP. TCP/IP packets are directly exchanged. Raw IP has both advantages and disadvantages. Advantages: <itemize> <item> No handshaking (= faster connections) <item> Authorization by Caller ID (= fast, safe, no password) <item> Fixed IP address (= a broken connection can be continued by redialing) <item> Higher data transfer rates <item> Better stability (smaller driver = almost no bugs) </itemize> Disadvantages: <itemize> <item> No handshaking => Configuration must occur beforehand (IP addresses,...) => sensible to use for only for one provider at a time <item> Authorization only by Caller ID => Dialin only possible from one's own number <item> Fixed IP address => must be known ahead of time, more IP addresses required, no dynamic assignment of addresses possible. </itemize> From this summary it should be clear under what conditions it makes sense to use raw IP. <!-- ttyI* devices --> <sect> ttyI: Configuration of the ttyI* devices (`Modem emulation') <label id="ttyI"> <sect1> ttyI_nomodem: Don't the ttyI* devices emulate an analog modem? <label id="ttyI_nomodem"> <p> No! The ttyI* devices just offer a similar communication interface, where all commands are started with <em/AT/. This makes it easy to reuse software that was written to communicate with a modem. <bf>Communication with a remote analog modem is not possible via the ttyI* devices!</bf> The real communication happens in digital, not analog form. <sect1> ttyI_dev: Which devices should I use for calls out or calls in? <label id="ttyI_dev"> <p> Only the ttyI* devices should be used. The cui* devices are created only for reasons of compatibility. Now that there is mgetty, there is not reason to use the cui* devices any longer. If they are used, locking will not work correctly (several programs could simultaneously attempt to use the same device). <sect1> ttyI_hdlc: How to I switch the modem emulation from X.75 to HDLC? <label id="ttyI_hdlc"> <p> With the option S14=3; for example &dquot;ATS14=3&dquot;. <sect1> ttyI_uucp: How can I poll with Taylor-UUCP using isdn4linux? <label id="ttyI_uucp"> <p> As usual, the same as with serial interfaces. Simply use /dev/ttyI* as the device, as the init string for the modem emulation you have to set the correct MSN or EAZ with &dquot;AT&Emsn/eaz&dquot;. <sect1> ttyI_speed: What speed should I set for the ttyI* devices? <label id="ttyI_speed"> <p> It doesn't matter. The driver internally always uses the full speed that ISDN offers. This is also given in the connect string. <sect1> ttyI_max: How many devices are the maximum supported number? <label id="ttyI_max"> <p> The maximum can be set by configuring ISDN_MAX at compile time. Currently, it is set to 64 by default, which means that up to 64 ttyI devices are supported. <!-- Trouble ttyI* devices --> <sect1> ttyI_nocarrier: When I dial with &dquot;ATD.....&dquot; I always get a &dquot;NO CARRIER&dquot;. <label id="ttyI_nocarrier"> <p> Before dialing, you have to enter &dquot;AT&E123456&dquot; (if 123456 is your own MSN; with 1TR6 give the one-digit EAZ). <sect1> ttyI_noincall: My ttyI* device/pppd does not recognize an incoming call. <label id="ttyI_noincall"> <p> Probably you did not tell the modem emulation with <tt>AT&E</tt> which MSN to use. For example, use <tt>AT&E123456</tt>; if your MSN is 123456. Please also note that only one application using the ttyI* devices will receive a ring for a particular MSN. Which will ring is selected by a loop over all ttyI* devices. A device is selected based on whether its parameters match (protocol, MSN) and whether it is currently not involved with another call. Therefore it does not make sense for multiple applications to register for the same MSN via the ttyI* devices, unless you want to have load sharing between the applications. <sect1> ttyI_callphone: Why can't I dial my telephone or fax from the ttyI* devices? <label id="ttyI_callphone"> <p> You can. However, ISDN differentiates different services. All outgoing calls with the ttyI* devices use the service &dquot;Digital Data&dquot;, which is incompatible with telephone or fax, so the call never gets through. Change the service recognition with the <tt>ATS18=1</tt> command to audio, then you can dial your telephone or fax. <sect1> ttyI_noconnect: I can't get a connection to my ISDN mailbox/BBS. <label id="ttyI_noconnect"> <p> There are several possible protocol parameters. There is HDLC, there is X.75 and there are several possible block sizes with X.75. You can tell the modem emulation about the block size with <tt>AT&</tt>. Mostly used is a block size of 2048 byte: <tt>AT&B2048</tt>. <sect1> ttyI_forcehangup: My modem emulation hangs. How can I force my card to hang up? <label id="ttyI_forcehangup"> <p> If there is really no process using your modem emulation any more, try: <code> cu -l /dev/ttyI0 dir +++ ath0 ˜. </code> Before and after &dquot;+++&dquot; you have to wait for a second, otherwise the modem emulation won't recognize it as the escape sequence (like a normal modem). Watch out for processes that (with &dquot;ps -ax&dquot;) have something like &dquot;I0&dquot; or &dquot;I1&dquot; in the second column, they have an ISDN terminal as their controlling terminal. You may have to kill them with kill. <sect1> ttyI_channelclosed: During a tty connection, I get a message from the kernel: &dquot;teles_writebuf: channel not open&dquot;. Then no more input is accepted for this connection. <label id="ttyI_channelclosed"> <p> Can happen when the partner cannot handle the large frames from i4l and simply closes the B channel during the transfer. Try making the frames smaller with AT&B512. <sect1> ttyI_x75uucp: When I use UUCP with X.75, I always get transfer errors! <label id="ttyI_x75uucp"> <p> Andreas Gutzwiller <tt><htmlurl url="mailto:andy@hippo.proxyon.imp.com" name="andy@hippo.proxyon.imp.com"></tt> wrote on 5 Dec 1996: <quote> I had to use the following settings, otherwise I only had errors. # Prot protocol-parameter g packet-size 512 protocol-parameter g short-packets y protocol-parameter g window 7 protocol-parameter g remote-window 7 protocol-parameter v packet-size 512 Now with large packets I can get ca 7300 cps. </quote> Holger Burbach <tt><htmlurl url="mailto:holly@cthulhu.pfalz.de" name="holly@cthulhu.pfalz.de"></tt> on 5 Feb 1997 had another solution: <quote> I have several XP users who poll without any problems. I did the following: First I set the send packet size for ttyI? to 1024 (&dquot;AT&B1024&dquot;) and then set the packet size for the g protocol in UUCP: protocol-parameter g packet-size 2048 protocol-parameter g remote-packet-size 0 As I said, it works fine.. </quote> <!-- Dial on demand = Unwanted dialouts --> <sect> dod: Unwanted dialout on demand <label id="dod"> <sect1> dod_how: How does dialout on demand work? <label id="dod_how"> <p> After you habe set up a network interface, and defined a route to it, then all ip packages will be routed to this interface. If the <tt/autodial/ mode has been enabled (see question <ref id="dialout_dialmode" name="dialout_dialmode"> on the dialmodes) then the interface will automatically trigger a dialout when it receives ip packages. (This means that <bf>any</bf> user can trigger a dialout.) Example: You open a browser with no or a local homepage. Nothing happens. You enter some url to connect to, this will send ip packages to the network interface - thereby triggering a dialout. Using dial on demand is a potentially dangerous (means expensive) feature: see question <ref id="dod_disaster" name="dod_disaster">. <sect1> dod_disaster: What is a charge unit disaster? <label id="dod_disaster"> <p> The charge unit disaster can happen for many reasons (see question <ref id="dod_causes" name="dod_causes"> for more details). However the results are identical: your computer dials out to your Internet Provider more often than you want, thereby increasing your telephone bill by a large amount (especially when you are not only charged for time online, but also a minimum amount/charge unit for every dialin). The term 'large amount' is rather flexible. Anything is possible: <itemize> <item>"Cheap": any DNS request opens the line, causing several dialouts per day (depending on your programs). If this happens 10 times a day, this makes up about 300 unneeded dialouts per month. <item>"Not so cheap": Some Windows 95 computer in your LAN triggers a dialout every 15 minutes for one of its silly broadcasts (see question <ref id="dod_winclient" name="dod_win95">). Makes up 96 dialouts per day, or 2880 per month. <item>"Medium": Your email client is configured to check every 5 minutes whether you have new emails at your Internet Service Provider. Makes up 288 dialouts per day, 8640 per month. <item>"Expensive": Keep alive packets prevent that your line ever hangs up. Your line is always on. Note: THIS IS NOT THE WORST CASE! <item>"More Expensive": Something goes wrong with dynamic addresses, leaving sockets open when hanging up. The sockets trigger another dialout when they try to resolve this, but since now you have a new ip address, the issue can't be resolved. The line will eventually hang up (when depends on your timeouts), but then re-open - since the sockets trigger another dialout. If you are unlucky, you never get the same ip address back, so this repeats continuously. Your line is almost always on, but on top of it you have to pay for many dialouts: if your timeout is 30 seconds, this makes up 2880 dialouts per day, 86400 per month. <item>"Most Expensive - Worst Case": You misconfigure dialout/callback, so that when your (the initiating) computer dials out to your Internet Provider, who then hangs up on you (e.g. authorization failed - maybe he also has some misconfiguration or unhooks despite being down), your computer immediately dials out again. This is only limited by the amount of time needed to dial out. If we assume 2 seconds for each attempt (conservative estimate), this makes up 43200 dialouts per day, or 1296000 per month! </itemize> This is no joke, and all these things have actually happened, even to real isdn4linux experts! See question <ref id="dod_off" name="dod_off"> on how to avoid any risk of this happening to you. <sect1> dod_causes: What can cause a charge unit disaster? <label id="dod_causes"> <p> There are many possibilities. See question <ref id="dod_strategy" name="dod_strategy"> on how to track down what is happening to you. See question <ref id="dod_disaster" name="dod_disaster"> on how expensive that could be. Here a non-comprehensive list of causes: <enum> <item>You compiled your kernel with the option Bridging by mistake. <item>ARP requests or broadcasts? You should run ifconfig with the options <tt>-arp</tt> and <tt>-broadcast</tt> to keep from opening connections in this way. You can recognize this one when you have a dialout, but <em/no/ data is transferred. <item>Other Broadcasts from the interfaces were being forwarded by ISDN. <item>If IP connections are still open with the line is disconnected and IP addresses are dynamically assigned, then the disaster is inevitable. Then a new connection is started to bring down the open IP connections, which fails because the IP address is now different. The line is hung up, but the IP connections are still open, the line is dialed again, and so on... This can only be avoided with the RST-provoking mode (see question <ref id="dod_rstprovoking" name="dod_rstprovoking">. A patch for it may be needed if it is not included in your distribution. The patch had found its way into the 2.0.x kernels, but not into 2.1/2.2/2.3. However, you can get an adjusted patch for 2.2.x kernels and some background information about it from: <url url="http://www.another.de/linux/router/">. See also question <ref id="syncppp_1stpacket" name="syncppp_1stpacket">. Also make sure to use ipppd's "defaultroute" option rather than <tt>route add/del default</tt> in ip-up/ip-down with it. <item>TCP retries trigger dialout: when the kernel tries to send tcp packets and does not receive any answer, then it will retry to send them (usually every 120 seconds). Check out whether you want to adjust the following parameters: <itemize> <item>/proc/sys/net/ipv4/tcp_syn_retries <item>/proc/sys/net/ipv4/tcp_retries1 <item>/proc/sys/net/ipv4/tcp_retries2 </itemize> Documentation can be found in <tt>/usr/src/linux/Documentation/proc.txt</tt>. <item>Requests from your local DNS trigger a dialout: see question <ref id="dod_localdns" name="dod_localdns">. <item>Sendmail triggers the dialout: see question <ref id="dod_sendmail" name="dod_sendmail">. <item>Windows 95 clients trigger the dialout: see questions <ref id="dod_winclient" name="dod_win95">, <ref id="dod_localdns" name="dod_localdns">, and <ref id="dod_winclient" name="dod_win95b">. <item>Samba triggers the dialout: see question <ref id="dod_samba" name="dod_samba">. <item>Netscape triggers a dialout when started: see question <ref id="dod_netscape" name="dod_netscape">. <item>dhcpd triggers dialouts: switch it off, and verify your configuration... <item>Manually close IP connections which are still open when the line goes down: see question <ref id="dod_closeipconnect" name="dod_closeipconnect">. <item>Your computer is crashed, but still processes interrupts: see question <ref id="dod_onlineoncrash" name="dod_onlineoncrash">. </enum> <sect1> dod_off: How can I safely turn off dialout on demand? <label id="dod_off"> <p> <enum> <item>To always dial out manually, set your dialmode to <tt/manual/ (see question <ref id="dialout_dialmode" name="dialout_dialmode">). Then use <tt>isdnctrl dial <device></tt> to dial out, and <tt>isdnctrl hangup <device></tt> to hangup. <item>Set your dialmode properly (see question <ref id="dialout_dialmode" name="dialout_dialmode">). For example, set dialmode to <tt/manual/ in <tt/ip-down/. Then dialouts will only be possible once after setting dialmode to <tt/auto/. <item>Delete the telephone number of the interface, or set an invalid one. Then you can see from the complaints in the syslog whether a process wants to send packets out to the world. <item>Switch the system off. <item>Delete your route to the ISDN device. For example, to disable any automatic dialouts: <code> /sbin/route del default /sbin/isdnctrl system off /sbin/ifconfig ippp0 down </code> To get things running again: <code> /sbin/isdnctrl system on /sbin/ifconfig ippp0 up /sbin/route add $GATE-IP dev ippp0 /sbin/route add default ippp0 </code> The latter method has the disadvantage that dialin is then no longer possible. </enum> <sect1> dod_strategy: How can I track down unexplainable dialouts? <label id="dod_strategy"> <p> Finding the reason of unexpected dialouts is the first step to stopping it. However, finding is usually more difficult than fixing the problem. This is what you can do to track it down: <itemize> <item> First disconnect your dialout server from your LAN to find out who is responsible for the dialouts: the dialout server himself, or some clients in your LAN. For Windows clients, see question <ref id="dod_winclient" name="dod_winclient">. <item> Try to find out which TCP/IP packet triggers the connection with &dquot;isdnctrl verbose 3&dquot;. A message should appear in the kernel message queue (visible with <tt>dmesg</tt>), like: <tt>OPEN: - TCP, port: 1686 - 540</tt> In this example, our computer is trying to pick up mail on port 540 (UUCP over TCP/IP over ISDN) - the port number can be looked up in <tt>/etc/services</tt>. Please note: only the triggering packet will be logged. <item> If you are using ipppd: get a tcpdump which can show data with the syncPPP encapsulation (this may require a patch - see question <ref id="trouble_tcpdump" name="trouble_tcpdump">). <item> Try to turn off one daemon after the other and see if things have finally quieted down. named, sendmail, and also smbd (Samba) are likely candidates to open connections (see questions <ref id="dod_localdns" name="dod_localdns">, <ref id="dod_sendmail" name="dod_sendmail">, <ref id="dod_samba" name="dod_samba">). <item> If broadcasts are your problem, you can also redirect the broadcast address to the dummy0 interface. It's not clean, but it works. </itemize> <sect1> dod_winclient: Can it be that the Win95 machine on my LAN is causing automatic dialouts? <label id="dod_winclient"> <p> Yes. When Windows 3.11/95 is started, then it tries to talks to the name server of your provider (if known), trying to look up some domains (e.g. WORKGROUP.xxx). To avoid this, these are your options: <itemize> <item> Switch off the feature <tt>Use DNS for Windows Names Resolution</tt> on all Windows computers on your LAN. <item> Set up a local DNS name server such that it will answer all requests. See question <ref id="dod_localdns" name="dod_localdns">. </itemize> <sect1> dod_localdns: I have set up a local DNS name server. Why does it cause unwanted dialouts? How can I find the cause? <label id="dod_localdns"> <p> Turn on debug level 1 in named and look at the logfile in <tt>/var/tmp</tt>. Often, you can find regular DNS requests from Windows machines. The problem is that names like "WORKGROUP.domain.de" are requested, i.e. names that the DNS could not know. Windows seems to be looking for its master browser or a domain controller (if you are fluent in German, see ct 12/99, page 224: "Schnitzeljagd - Netzwerkumgebung und Browserdienst im Windows-Netzwerk" for more details). To work around this problem, you can set up your domain name server with cname = "WORKGROUP.domain.de" (other domain names are also possible). Or set up a Primary Domain Controller within your LAN. You can also use diald to control dialouts for DNS request. <sect1> dod_forwarddns: I have set up my name server in 'forward' mode, with one forward address. Now it dials out about every minute? <label id="dod_forwarddns"> <p> From time to time, the name server will query its forwarder, which will trigger a dialout. Since your ISP uses dynamic ip addresses, the request is sent out with the wrong ip address at startup of the dial-in connection. Therefore, no answer will be received. Bind waits for one minute before resubmitting. If your line has come down in the mean time, this will trigger a new dialout, resulting in a different ip address, and so on... For a workaround to this problem you can shorten the retransmission time as described in question <ref id="dialout_bind" name="dialout_bind">. Alternatively, you can set the option &dquot;dialup yes;&dquot; in the options block of named.conf. This will cause named to do only one interaction with a forwarder (triggering a dod) at startup. After that it will wait for some very long interval (24h?) before another query with the forwarder. Only during actual lookup it will do negotiations with the forwarder (this is usually when you have already dialed out anyway). <sect1> dod_sendmail: How can I get sendmail to not initiate any connections without local mail being left undelivered? <label id="dod_sendmail"> <p> First you have to get sendmail to no long open any DNS connections. You need to activate the following features: &dquot;nodns&dquot;, &dquot;nocanonify&dquot;. If you have a smarthost, you need to make sure that this name does not call the name server. You can either set it directly as an IP address, or add the name to /etc/hosts (/etc/host.conf should then contain &dquot;order hosts bind&dquot;) You should set all non-local mailers as &dquot;expensive&dquot; (&dquot;define(SMTP_MAILER_FLAGS, e)&dquot;), and then forbid sendmail with &dquot;define(`confCON_EXPENSIVE', `True')&dquot; from automatically connection to expensive mailers. The call to sendmail should no longer include a time for the &dquot;-q&dquot; option (e.g. only &dquot;-bd -os -q&dquot;). &dquot;-os&dquot; means that all mail will be queued (which won't prevent local mail from being delivered immediately). The only catch is that when booting, mail that might still be in the queue will be sent by sendmail, even though the network is not yet up. Therefore, when booting you should remove all mail from /var/mqueue before starting sendmail, and then return it once sendmail has been started. Mail to expensive mailers will now only be send with the explicit call &dquot;sendmail -q&dquot;. <sect1> dod_samba: The samba package always triggers dialouts for me. How can I prevent this? <label id="dod_samba"> <p> When nmbd starts up it tries to bind to or all interfaces, which is what triggers the ISDN dialup. The best way to solve this is to set "bind interfaces only = yes" and "interfaces = eth0" in smb.conf (in case you want to use Samba only in your LAN). Alternatively, you can give the samba daemon an internal ip address upon startup. First find out which ip address samba is trying to connect to (e.g. with netstat or tcpdump). Then start samba with: <code> nmdb -S -B -I </code> if your Linux computer has as ip address, and all users are in the same subnet ( See also the above question: set -broadcast and possibly -arp when defining the interfaces! Check out the help pages for the Samba configuration file for further possibilities on preventing dialout (I was told there should be some explicit dialup parameter which prevents it to cause many dialouts). <sect1> dod_netscape: How can I get Netscape to quit initiating dialouts when starting? <label id="dod_netscape"> <p> Most likely in the preferences a non-local home page has been listed. Only a home page that Netscape is able to load immediately (e.g. &dquot;file://localhost/xxx&dquot;) won't cause an immediate dialout. Alternatively you can also set up a cache daemon that saves pages that are often needed. Second check your proxy settings. When giving a complete name instead of an ip address, Netscape may try to do a DNS lookup to resolve the name to an ip address on startup. In this case provide Netscape with an ip address. Another thing is that Netscape tries to contact its news server. If you don't want to use this feature then you can enter the name Netscape uses for lookup (probably 'news') in your local DNS or in your /etc/hosts, and let it point to localhost. <sect1> dod_rstprovoking: Why should I use the RST-provoking mode/patch? <label id="dod_rstprovoking"> <p> If on every dialup (in auto dialout mode) you get a different ip address (dynamic ip), and the dialup connection gets terminated (e.g due to inactivity) while some ip connections have not yet been closed, then the following problem will occur: when the program tries to close the connection this will trigger a new dialout. Since this will yield in a new ip address, the closing attempt will fail. After the timeout period another dialout will be attempted, with the same result, leading to a dial on demand disaster. To prevent this problem the RST-provoking mode has been invented. If on the closing attempt a new dialout is opened and the ip address changes, then the kernel will send a ip packet with the reset flag on. This will close down the open connection, preventing the dial on demand disaster. To activate the RST-provoking mode use the command <code> echo 7 > /proc/sys/net/ipv4/ip_dynaddr </code> Use 5 instead of 7 to prevent syslog warnings. Check the current status with: <code> cat /proc/sys/net/ipv4/ip_dynaddr </code> Your distribution may or may not have the patch for this rst-provoking mode included, it was not liked in the kernel code for kernels newer than 2.0.x. <sect1> dod_closeipconnect: After closing the line, I discover with <tt>netstat -nt</tt> that IP connections are still open. How can I close these manually? <label id="dod_closeipconnect"> <p> This may only work with the RST-provoking mode (mentioned in question <ref id="dod_causes" name="dod_causes">): You can bring the interface &dquot;down&dquot; then back &dquot;up&dquot;. When you do this, it will try to dial out. But if you have removed the outgoing telephone number, then &dquot;no outgoing number...&dquot; appears in the syslog, and as soon as the interface is &dquot;up&dquot;, all connections will be closed. You can prevent those open IP connections to trigger new dialouts if you add a special firewall rule in <tt>/etc/ppp/ip-down</tt>, and remove it in <tt>/etc/ppp/ip-up</tt>. This firewall rule drops all tcp packets which are not in SYNSENT state. Add this in <tt>/etc/ppp/ip-down</tt> for a 2.2.x kernel: <code> ipchains -A output -j DENY -p tcp -i <interface> ! -y </code> Add this in <tt>/etc/ppp/ip-up</tt>: <code> ipchains -A output -j DENY -p tcp -i <interface> ! -y </code> (As is the case for all firewall rules: it is best to put this into a separate script which is called with either a start or a stop parameter.) Please note that this firewall rule only matches whole packets, no fragments. A fragment will always bypass the firewall and trigger a dialout. <sect1> dod_onlineoncrash: Is it possible that even with a crashed computer a ISDN connection remains open (and the charge units accumulate)? <label id="dod_onlineoncrash"> <p> The ISAC chipset, which is in use on many ISDN cards, can be run in either auto mode, or in non-auto mode. When run in auto mode, the connection could be up when the computer is crashed (the card keeps it up and running). Since the HiSax driver uses nonauto mode, this should not happen with ISDN4LINUX. Once no interrupt is processed on your machine, the connection will stop at maximum half a minute later. Only in the unlikely event that your machine is crashed, while interrupts are still processed normally, this could happen. <!-- Chargeint --> <sect> chargeint: Chargeint <label id="chargeint"> <sect1> chargeint_whatis: What does Chargeint? <label id="chargeint_whatis"> <p> Chargeint is a way to reduce your costs when you have charges based on your <bf/time online/, and the interval between two charges (the Charge Interval) is relatively large (e.g. per minute). Chargeint only hangs up two seconds before the end of a charge unit. isdnlog can be used to set the length of the charge unit (i.e. Charge Interval) according to the time of day and the date. <sect1> chargeint_config: How should I configure Chargeint? <label id="chargeint_config"> <p> You can set the length of a charge unit manually via the isdnctrl parameter <tt/chargeset/, or set up isdnlog to do this automatically for you: <enum> <item>Set up isdnlog, so that it has all the information about your location and your telephone company (so that it knows your rates). <item>Start isdnlog with the options <tt>-h0</tt> and <tt>-w</tt>. <item>Set your huptimeout as you like (idle time needed before i4l will consider a hangup). E.g.: <code> /sbin/isdnctrl huptimeout ippp0 5 </code> Then i4l will hang up 2 seconds before the end of your charge unit, if the 5 seconds before (huptimeout) no activity has happened on the line. </enum> <sect1> chargeint_whennot: When does it <bf/not/ make sense to use the chargeint? <label id="chargeint_whennot"> <p> <enum> <item>It does not make sense to use Chargeint when you are charged <bf/per data volume/, or per <bf/flat fee/. Chargeint can only reduce your costs when you are charged <bf/per time online/. <item>Also it makes no sense if you are charged in small units (e.g. per second rather than per minute). <item>Chargeint may or may not make sense when every new dialup costs you fixed amount on top of the variable charges (depending on the rates). <item>There are problems when the ip address is assigned dynamically. A broken connection cannot simply be restarted (since the IP address has changed). The interrupted FTP, telnet or WWW connection must then be newly established. </enum> <sect1> chargeint_correcttime: How can I be sure that the chargeint patch is using the correct time? <label id="chargeint_correcttime"> <p> It's best to synchronize the clock in your own computer with that of the switching station by calling isdnlog with option <tt>-t2</tt>. <sect1> chargeint_nohangup: The connection doesn't end with timeout. <label id="chargeint_nohangup"> <p> Chargeint will only hangup if there was no activity on the line. Possibly your service provider uses a router (e.g. Cisco) which sends a &dquot;keep alive&dquot; packets every ten seconds. If the Cisco doesn't get an answer for its keep alive packets then it will stop routing. This normally happens after the 4. or 5. keep alive packet. Very recently (begin of 2001), support for Cisco's keep alive packages has been corrected, so you can either use it, or tell the provider not to use keep alive packets (<tt>&dquot;no keepalive&dquot;</tt> in the Cisco configuration). It could also be that it's not the keep alive packets that are keeping the connection open, but rather OSPF routing updates. The sending of these updates can only be switched off on the Cisco. You can configure &dquot;snapshot server&dquot; on the BRI interface. That means it will send out routing updates only when they are received through this interface. However, nowadays the most likely cause for open connection is that connection requests looking for a backdoor or a file sharing application cause issues like this. You can use the <tt>active-filter</tt> option of ipppd to indicate which packets should be regarded as link activity. See the man page for more details. A configuration could be like this: <code> active-filter 'outbound and not icmp[0] == 3 and not tcp[13] & 4 != 0' </code> <!-- 2 and more channels: MPPP, raw bundling --> <sect> 2channel: Channel bundling (MPPP, raw bundling) <label id="2channel"> <sect1> 2channel_whatis: What is channel bundling and how can I use it? <label id="2channel_whatis"> <p> Channel bundling is currently supported by isdn4Linux in two variations: <itemize> <item><bf>Raw Bundling</bf> (configuration of so-called slave channels) <item><bf>MPPP</bf> (based on syncPPP) </itemize> Both variations have their own advantages and disadvantages. See the following questions. Dynamic adjustment is supported for MPPP by the program <tt>ibod</tt> - see question <ref id="2channel_mpppconfig" name="2channel_mpppconfig"> for more details. <sect1> 2channel_raw: What is raw bundling? <label id="2channel_raw"> <p> Raw bundling works similarly to raw IP, only with several channels. Therefore, it has the theoretical advantages and disadvantages of raw IP. Raw bundling requires a network interface for each channel that is used. One network interface, the so-called master interface, controls the establishment and breaking of connections. For each further channel, an additional so-called slave interface is configured, that is automatically switched on by the master interface. <sect1> 2channel_rawconfig: How do I configure raw bundling? <label id="2channel_rawconfig"> <p> The master interface is created as usual with <code> isdnctrl addif master interface </code> and configured. For all required slave channels, slave interfaces are created with the command: <code> isdnctrl addslave master interface slave interface </code> and configured as usual (e.g. &dquot;isdnctrl sdelay slave interface delay&dquot;). <sect1> 2channel_rawgoodbad: What are the advantages and disadvantages of raw bundling? <label id="2channel_rawgoodbad"> <p> Raw bundling has all the advantages and disadvantages of raw IP. Compared to MPPP, raw bundling has the advantage that isdn4linux itself can open and close the needed slave channels. Unfortunately raw bundling still has problems with transfer rates. See the further questions below. <sect1> 2channel_mppp: What is MPPP? <label id="2channel_mppp"> <p> MPPP or MP or MPP (Warning: MP is also an acronym for 'Multi Processor') stands for Multi Point to Point and means bundling of several channels to one logical stream. It's a variation of the normal syncPPP. Accordingly, it inherits all its advantages and disadvantages. Just for your information: ipppd does MPPP according to RFC 1717, instead of the newer RFC 1990 (MLP). In contrast to raw bundling only one net interface is needed as interface to the ipppd, since the ipppd handles all its channels by itself. Incoming data is distributed round-robin by the ipppd on all available channels. These channels do not necessarily have to be ISDN channels. In theory, modem connections could be mixed with ISDN channels. However, here we only cover ISDN channels. <sect1> 2channel_mpppgoodbad: What are the advantages and disadvantages of MPPP? <label id="2channel_mpppgoodbad"> <p> A disadvantage is that the slave channel has to be activated &dquot;manually&dquot;. ipppd cannot by itself turn the slave channel on and off as it needs to. The normal automatic functions of ipppd are either unreliable (auto hangup) don't work at all (auto dial). This is not true for the other encapsulations. The transfers rates are very good (ca. 30 KB/s with 4 channels). <sect1> 2channel_mpppconfig: How do I configure MPPP? <label id="2channel_mpppconfig"> <p> First ensure that support for MPPP has been switched on for compilation of your ISDN modules. Then define a (normal) interface for ipppd (e.g. &dquot;isdnctrl addif ippp0&dquot;, etc). This interface will be used as your master interface. Then you must configure a slave device for every additional channel (e.g. &dquot;isdnctrl addslave ippp0 <slave_interface>&dquot;, configure slave_interface, etc - see the i4l manual for more). To enable MPPP negotiation, ipppd must be called with the &dquot;+mp&dquot; option and both devices have to be given to ipppd. Please note that the name of both devices has to start with &dquot;ippp&dquot;. To use channel bundling you must first activate the 'master' or initial call. Now you can add the slave channels with the command: <code> isdnctrl addlink device </code> and close them with the command: <code> isdnctrl removelink device </code> This is different to other encapsulations of isdn4linux! If addlink gives you error -2, then this means that there are no slave devices configured. Error -5 means that ippp0 is not connected. Please also note, that the slave device has to be in dialmode <tt/auto/ for this to work. For manual control, use <code> isdnctrl dial slave </code> and <code> isdnctrl hangup slave </code> When using manual control please ensure that the slave device is shut down before the master device. Currently (August 2002) there is a hard-to-fix bug in the MPPP code which will cause a crash on the next dialout. A patch exists which cures the symptoms to prevent the crash (see mailing list). However, since the dialout will fail in any case it is best to avoid this situation altogether by using the proper shutdown sequence. With syncPPP, there is no automatic activation of slave devices, they have to be added and removed. However, there is the program <tt>ibod</tt> available, which can do this automatically. Have a look at: <url url="http://www.compound.se/ibod.html"> or (for a version extended by Karsten Keil): <url url="http://www.suse.de/~kkeil/xibod/"> In the file <tt>etc/rc.isdn.syncppp.MPPP</tt> in the isdn4k-utils package you can find a sample script (unfortunately missing in some i4l versions). Please note that your Internet Provider has to allow you to make use of these features. Also, there may be a limit on how many channels you are allowed to open at the same time. It could be that all links are dropped when you exceed this limit. <sect1> 2channel_mpppcompile: I tried MPPP but it doesn't work. The ipppd writes in the debug log something like: &dquot; ... rcvd (0)(proto=0x3d) c0 00 00 00 80 fd 01 01 00 0a ... sent (0)(LCP ProtRej id=0x2 00 3d c0 00 00 00 80 fd 01 ...&dquot; <label id="2channel_mpppcompile"> <p> You forgot to compile MPPP/RFC1717 support into the ISDN Subsystem. Recompile with this option enabled. <sect1> 2channel_cantlocateippp1: When trying to use MPPP I get the error message &dquot;modprobe: Can't locate module ippp1&dquot; and &dquot;ipppd: ioctl(SIOCSIFMTU): No such device...&dquot;? <label id="2channel_cantlocateippp1"> <p> This is a pecularity of ipppd. It tries to set MTU even for slave devices, and the kernel can not find a corresponding network device. You can safely ignore this information message, MPPP should work nevertheless. <sect1> 2channel_multiplenumbers: How can I set up multiple number when using MPPP? <label id="2channel_multiplenumbers"> <p> Master and slave device are fully independent of each other, except for using the same network device to deliver packets. Setting up multiple number for master and slave devices will result in synchronized dialout (to the same number). Therefore it is best to give the slave device no number by default and set up the slave with the same number as the master in some ip-up script. <sect1> 2channel_freebchannel: How could I set up isdn4linux to free the second B-channel if a phone call comes in? <label id="2channel_freebchannel"> <p> Well, this is a tough one, due to technical limits. Even if isdn4linux freed a B-channel, the exchange would not repeat the setup call. Therefore, the phone would not ring. The phone only signals a second incoming phone call if you are on the phone with another call that could be suspended. One option would be that isdn4linux frees one B-channel, then takes the call, and transfers it to the phone via ECT (explicit call transfer); however, this feature requires proprietary (unknown) protocol extensions, and is usually only available behind large private exchanges - therefore not implemented in isdn4linux. Another option is that isdn4linux frees one B-channel, takes the call, then suspends it. However, the user would have to know to resume it without any phone ringing. The most sensible option is that you handle it will a phone application making use of isdn4linux. Possibly ant-phone could be used for such a purpose: <tt><url url="http://www.antcom.de/"></tt> <!-- Pecularities of your counterpart (remote device) --> <sect> remote: Pecularities of the remote ISDN device <label id="remote"> <sect1> remote_win95: How do I configure Windows95 to dial successfully into my isdn4linux computer? <label id="remote_win95"> <p> Configure your dialout network like this: <itemize> <item>Type of server: PPP:Windows 95, Windows NT 3.5, Internet <item>Extended options: unselect all options <item>Network protocolls: only select TCP/IP <item>Standard gateway <item>Switch off IP header compression for the beginning (for more details on compression with ipppd see question <ref id="syncppp_compression" name="syncppp_compression">). <item>Remainder of TCP/IP stuff (ip address, nameserver,...) as applies to you. </itemize> <sect1> remote_mac: I'd like to exchange data with a Macintosh (Leonardo card), what do I or the Mac user have to watch out for? <label id="remote_mac"> <p> Currently, the Leonardo protocol is not supported by i4l. When you call the Mac, he should set the protocol to X.75 or HDLC. When he calls you, he must explicitly set the protocol (e.g. by inserting an &dquot;X&dquot; for X.75) in the called number. <sect1> remote_macpap: A Macintosh with a Leonardo card tries to call in, and wants to negotiate chap md5. How can I switch it to CHAP/PAP? <label id="remote_macpap"> <p> You can't. The user should use LeoPort (always included with the card) and switch the CTB port to the ISDN card. Then with FreePPP 2.5v2 <tt><url url="http://www.rockstar.com"></tt> set the Leo as the modem and configure FreePPP as usual. Then PAP/CHAP can be set. <sect1> remote_cisco: How does isdn4linux work with a Cisco (HDLC) on the other side? <label id="remote_cisco"> <p> On the Cisco router the &dquot;keep alive&dquot; packets have to be turned off. isdn4linux has to be configured with HDLC, transparent, with Cisco encapsulation: <code> isdnctrl l2_prot <interface> hdlc isdnctrl l3_prot <interface> trans isdnctrl encap <interface> cisco-h </code> <sect1> remote_ispa: What settings does ISPA etc. (DOS, Windows) need to work with the standard settings of isdn4linux? <label id="remote_ispa"> <p> The following configurations are possible (these also apply to the other drivers from H. Hanewinkel, i.e. CINDI, CANDI, WISPA...) that can be found via <tt><url url="http://www.informatik.uni-bremen.de/˜henker/dank"></tt> <verb> i4l side ISPA side ==================================================== isdnctrl l2_prot isdn0 hdlc \ isdnctrl l3_prot isdn0 trans -h0 isdnctrl encap isdn0 rawip / ---------------------------------------------------- isdnctrl l2_prot isdn0 hdlc \ isdnctrl l3_prot isdn0 trans -h1 isdnctrl encap isdn0 uihdlc / ---------------------------------------------------- isdnctrl l2_prot isdn0 x75i \ isdnctrl l3_prot isdn0 trans -l0 isdnctrl encap isdn0 rawip / ---------------------------------------------------- isdnctrl l2_prot isdn0 x75i \ isdnctrl l3_prot isdn0 trans -l1 isdnctrl encap isdn0 uihdlc / ---------------------------------------------------- </verb> The parameter with the least problems is -h0. <sect> leased: Leased lines <label id="leased"> <!-- Config Leased line/D64S --> <sect1> leased_flatrate: What's the difference between a leased line and a flat rate? <label id="leased_flatrate"> <p> A leased line requires a special setup of your S0 interface. After that, you can not reach any other destination than the one the leased line is set up for. It's also rather expensive. A flat rate is still a normal dialup, therefore the setup should be done like any dialup connection. The only difference from a normal dialup is the pricing. See section <ref id="dialout" name="dialout">. Also please note that the connection on a flat rate will usually be stopped by your internet provider if you stay on for too long - so you can not rely on being online all the time, if this is what you desire. <sect1> leased_nosignal: How does establishing and ending a connection work with D64S without signaling? <label id="leased_nosignal"> <p> The data is simply sent out! Other than a ping, there is no way to find out whether the D64S or 2MB line is up or not. Only S01 or S02 lines have a D channel and have something to use with signaling, however the best known solutions also use this 16kb for data transfers to get 144kb instead of 128kb (i4l can only to 128kb). <sect1> leased_hisaxconfig: With i4l, how do I configure my card on a D64 leased line? <label id="leased_hisaxconfig"> <p> A later version of the new HiSax driver supports D64. Configuration is normal with the following specialities. HiSax has to be run in leased mode: <code> /sbin/hisaxctrl HiSax 5 <channel> </code> in case HiSax was loaded with &dquot;id=HiSax&dquot;, where <channel> can be 0 or 1. Additionally to the normal configuration, the following commands are important: <code> /sbin/isdnctrl bind HiSax,<channel> /sbin/isdnctrl eaz isdn0 1 /sbin/isdnctrl addphone isdn0 out 2 /sbin/isdnctrl addphone isdn0 in 3 </code> if &dquot;isdn0&dquot; was used as interface name. The interface has to be set to &dquot;up&dquot; and a route associated with it. See the Readme's in the HiSax package. <sect1> leased_x75: How do I configure X.75 on a D64 leased line? <label id="leased_x75"> <p> Use a later HiSax version. First initialize the ttyI* device you want to use with &dquot;AT&E0&dquot; (set usage of first B-channel) and &dquot;ATS0=1&dquot; (autoanswer on first ring). Then set HiSax in leased mode: <code> /sbin/hisaxctrl HiSax 5 <channel> </code> This will simulate a call for MSN1 on the configured channel (0 or 1) (incoming number = LEASED0). <sect1> leased_splitline: With i4l, can I use one channel as a leased line and the other as a dialup line? <label id="leased_splitline"> <p> Yes and no. You can configure HiSax for both at the same time, however you can only use one of them at any point in time (you have to switch off the leased line before dialing out). It may work occasionally simultaneously, however the driver has not been written for it so the results are not deterministic. Also make sure that you use the correct channel. <!-- Dialin --> <sect> dialin: Configuration of a Dial-In Server <label id="dialin"> <sect1> dialin_config: How can I enable others to login via ISDN? <label id="dialin_config"> <p> Some configuration examples can be found at: <url url="http://www.rosat.mpe-garching.mpg.de/~web/ISDN.html">. If you have trouble setting it up, try to obtain the latest packages for isdn4linux (see question <ref id="distrib_getlatest" name="distrib_getlatest">). As usual, you can also ask in the mailing list. In general, there are several ways to configure dialin, depending on how you want others to dial in. <itemize> <item>Set up networking devices for dialin via syncppp, or rawip. Set option <tt/secure off/ to allow everybody to dial in, or set option <tt/secure on/ to only allow dialin by the isdn numbers you configure, which you set up with <tt>isdnctrl addphone <device> in <phonenumber></tt>. It has been reported that you need to set option <tt/ms-dns/ for ipppd to have successful IPCP negotion. <item>Use the ttyI* devices for asyncppp or X.75. </itemize> Here some more details for setting up the ttyI* devices. The setup is like for a serial port. Start a getty (mgetty from Gert Doering is highly recommended) on one of the ISDN devices (/dev/ttyI*). The entry in /etc/inittab looks like this: <code> I0:56:respawn:/usr/local/sbin/mgetty ttyI0 I1:56:respawn:/usr/local/sbin/mgetty ttyI1 </code> The init string needs to be entered in the <tt>mgetty.config</tt>, since mgetty needs to know which MSN or EAZ to listen to. For example, if your MSN is 123456: <code> port ttyI0 modem-type data speed 38400 init-chat &dquot;&dquot; ATZ OK AT&E123456 OK AT&B512 OK </code> For X.75 the block size was set to 512 bytes. Alternatively you can enter the entire configuration onto a single line in <tt>/etc/inittab</tt> (here printed on two lines!): <code> i0:45:respawn:/sbin/mgetty -D -m '&dquot;&dquot; ATZ OK AT&E123456 OK AT&B512 OK' -s 38400 ttyI0 </code> The most elegant way is to use iprofd. This daemon takes advantage of the <tt>AT&W0</tt> command in the i4l modem emulation. You start iprofd with a path as parameter, e.g. <tt>&dquot;iprofd /etc/i4lprofile&dquot;</tt> Then with minicom or another terminal program, open an ISDN tty device and enter the necessary AT command by hand. When finished, enter the command <tt>AT&W0</tt>, then the kernel notifies iprofd to write the current configuration to the file. From now on it is enough to start iprofd in you isdn init script, and to initialize the appropriate ISDN tty devices with <tt>ATZ</tt>. <sect1> dialin_manyparallel: How can I allow several people to call in to me at the same time? <label id="dialin_manyparallel"> <p> You have to configure exactly as many gettys or network interfaces as the number of people allowed to call in at one time. These gettys or network interfaces can be set to the same MSN, since several people can be connected to a MSN at the same time (as long as there are B channels free). However, not more than one getty can be assigned to a single ttyI* device. <sect1> dialin_manycards: When using several ISDN cards, how can I react upon on a call received via a specific ISDN card? <label id="dialin_manycards"> <p> You can use the EAZ mapping feature for this to map incoming MSN numbers to new internal MSN numbers, in the same way as described for question <ref id="dialout_manycards" name="dialout_manycards">. Usage of a card can be prevented by using the dash during the mapping. Please note that it is not possible to have any limitations based upon the B channel, since channel assignment is normally done by the exchange. <sect1> dialin_analogditalsamettyi: Can I configure a ttyI* device to accept both digital and analog modem dialins? <label id="dialin_analogditalsamettyi"> <p> Since the digital mode requires different register settings than the analog mode, this is not possible. Therefore you have to set up a two dedicated devices for this purpose. Please note that analog modem dialins are only possible if card and isdn4linux driver support it, which is only the case for a few cards. <sect1> dialin_fixedip: How can I assign fixed ip addresses per user who dials in via ipppd? <label id="dialin_fixedip"> <p> Just specify the fixed ip address with the user name and password in the pap/chap-secrets file (see man ipppd). <sect1> dialin_hdlc: Someone would like to dial in to my mgetty with HDLC. Is ttyI1 correct, or do I have to start with ttyI0? <label id="dialin_hdlc"> <p> No, it doesn't matter. It also has nothing to do with the number of the B channel (0 or 1). You just have to activate HDLC in the init string (ATS14=3). <sect1> dialin_autoppp: Is it possible with mgetty to automatically start pppd when LCP frames are received? <label id="dialin_autoppp"> <p> Yes, it is. This feature is called `AutoPPP'. See the configuration for mgetty. <sect1> dialin_passwd: How can I have (i)pppd check passwords from /etc/passwd instead of /etc/ppp/pap-secrets when someone dials in? <label id="dialin_passwd"> <p> ipppd needs to be started with the options &dquot;login&dquot; and &dquot;auth&dquot;. In /etc/ppp/pap-secrets, each user must have the following line to allow only certain users: <code> login-name * &dquot;&dquot; * </code> To allow all users simply: <code> * * &dquot;&dquot; * </code> The latter can also be achieved when the file pap-secrets does not exist. <sect1> dialin_ignored: I keep getting the message &dquot;isdn_tty: call from XXX - YYY ignored&dquot;. Why does isdn4linux (syncPPP) ignore this dialin attempt? <label id="dialin_ignored"> <p> There are two possible explanations. Either your own MSN (here: YYY) is not correctly set with &dquot;isdnctrl eaz interface YYY&dquot;. Or &dquot;isdnctrl secure interface on&dquot; was set, without allowing calls from the incoming number (here: XXX) with &dquot;isdnctrl addphone interface in XXX&dquot;. <sect1> dialin_async: A SunISDN tries to dial into my i4l system. <label id="dialin_async"> <p> The Sun tries to communicate with asyncPPP. ipppd can't handle this, you have to use the ttyI* devices and the standard pppd. <!-- Callback --> <sect> callback: Callback <label id="callback"> <sect1> callback_delay: An incoming call is rejected by i4l. i4l then calls back. The reject is not recognized by the other side which keeps on dialing to i4l. <label id="callback_delay"> <p> Most problems with callback can be solved by adjusting the callback delay with <tt>isdnctrl cbdelay</tt>. One second on the triggering side A (set callback mode to out) and two seconds on the triggered side B (set callback mode to in) has been successful in most cases. <p> The reason for the problem is a design bug in the link level driver. A calls B to trigger a callback. B rejects the call and calls back to A, establishing a working connection within less than 4 seconds. However, the triggering call from A to B will need 4 seconds to be terminated by the ISDN provider (giving other devices on B's side a chance to take the call). When it is finally terminated, the working connection from B to A is unfortunately also terminated. <sect1> callback_cisco: Somehow i4l can not callback a Cisco? <label id="callback_cisco"> <p> Torsten Hentschel <tt><htmlurl url="mailto:Torsten.Hentschel@DInet.de" name="Torsten.Hentschel@DInet.de"></tt> wrote on 3 Oct 1996: <quote> A Cisco may dial so heavily that the ipppd has no chance to callback. That's how they are programmed (firm statement of a Cisco developer): If a Cisco receives a packet that should be routed through a &dquot;dial on demand&dquot; telephone connection, and there is a D-channel available for dialing out, it dials out immediately. If in such a situation (which has be the case with Delta Internet for half a year now) a Cisco with 8 D-channels is on the other side and somebody does a simple &dquot;ping RemoteIP&dquot; then the Cisco will use (worst case) all 8 D-channels to dial out. Of course it can't dial the same telephone number with two D-channels in parallel (would be immediately busy). Its programming is not so stupid, but it sets up the next D-channel for dialout before it assumes the previous D-channel as failed. Such a Cisco works like a machine gun in respect to dialout. And i4l won't get a free D-channel for dialin if the Cisco doesn't want. The bad thing: a Cisco always expects (even when configured on &dquot;callback client&dquot; = i4l dials back) that the other side unhooks the line, then both hang up and then comes the callback. Username and password always have to be exchanged before the callback is allowed when using PPP, to be sure that the person requesting callback is allowed to do so. (Cisco seems to obey the rules of the (German) Telekom that no information are to be ex- changed without a B-channel connection. A callback request just by caller id could in doubt be considered as a transmission of information). </quote> Torsten Hentschel <tt><htmlurl url="mailto:Torsten.Hentschel@DInet.de" name="Torsten.Hentschel@DInet.de"></tt> additionally wrote on 20. Nov 1996: <quote> I've often tried callback over PPP with two CISCOs. From my experience, trials in the combination CISCO - Linux will not be successful. A CISCO always handshakes a callback request via PPP. To do this, the other side has to first unhook and then do all the handshaking (authentication,...). Then both hang up and the callback is placed. isdnctrl commands of Linux influence only the kernels net devices and have no or hardly any influence on how the ipppd handles callbacks. He does not recognize that he is supposed to expect that the remote side calls back. Accordingly he rejects the offer of the CISCO via PPP, that the CISCO is ready to call back. Then the CISCO assumes that it should not call back (it wants to see an explicit callback request during the PPP handshaking). The CISCO will confirm this when you log onto it and check with these commands: deb ppp chap deb ppp negotiotion deb ppp error term mon its debug messages about the dial in trials of your Linux computer. You have to do this via telnet instead of on the console - otherwise the CISCO won't be able to handle the logging via the serial interface. </quote> <sect1> callback_ascend: Callback from an Ascend works only when I set &dquot;Active=Yes&dquot; in the Ascend menu; but then the Ascend keeps calling me, even when my machine is off. <label id="callback_ascend"> <p> Ulrich Klein <tt><htmlurl url="mailto:ulik@hprc.tandem.com" name="ulik@hprc.tandem.com"></tt> wrote on 14 Dec 1996: Somewhere in the Ascend menus you can set &dquot;dial broadcast&dquot; to &dquot;no&dquot; or &dquot;off&dquot;. Otherwise the thing will dial with every broadcast. At least that helped me. In case anyone from the network on which the Ascend is attached really wants to establish a connection, then you have to use the strange filters. I believe there's one that will dial out only for callback. <sect1> callback_banzai: How can I callback a Banzai!? <label id="callback_banzai"> <p> Jan-Olaf Droese <tt><htmlurl url="mailto:jano@layla.RoBIN.de" name="jano@layla.RoBIN.de"></tt> wrote on 31 Jan 1997: On the Banzai side, a "c" should be added to the outgoing number, so it will be ready for the return call. Just to be safe, you can the dialout attempts on the Banzai to 1, so there won't be any call collisions. On the i4l I've set the following: <code> isdnctrl callback isdn0 in isdnctrl cbdelay isdn0 1 </code> <sect1> callback_microsoft: Does isdn4linux support Microsoft Callback (CBCP)? <label id="callback_microsoft"> <p> Yes, this is implemented in ipppd. To enable it you have to set the parameter &dquot;callback 6&dquot; as an ipppd option on the client side for an admin managed callback. This means the server will call back on the number it has been configured for. More interesting is a user managed callback, since the number to be called back can be provided by the user. Set the paramter &dquot;callback 123456&dquot; if you want to be dialed back on number 123456. To start the callback trigger it from the client via: <code> isdnctrl cbdelay <device> 5 isdnctrl callback <device> out </code> Please remember that using the CBCP callback always requires both parties to connect and exchange data, so telephone charges will be incurred. Please note that the man page may be confusing about the callback parameter for ipppd. Please note these hints from NOTES.IPPPD: <verb> - 'callback type[,message]' enables the callback feature also UNTESTED! ie: 'callback 0' -> simple callback (info via auth. etc.) 'callback 3,12346' -> us E.164 (tel) number 123456 for callback 'callback 6' is different. This value means, that the whole negotiation is done with a seperate protocol after the authentification phase. Currently it's not possible to set any options in this case. The ipppd accepts everything from the remote side. </verb> The server side is not tested so far - please let me know if you have some feedback on using CBCP as a server). If you have a Red Hat distribution, setting the following parameters in ifcfg-ippp0 might do the trick for an admin managed callback: <code> CALLBACK=out CBDELAY=5 CBCP=on </code> For user managed callback please follow the hints on: <url url="https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=125710">. <!-- Isdnlog --> <sect> isdnlog: Isdnlog <label id="isdnlog"> <sect1> isdnlog_rates: Where do I get the latest rate information? <label id="isdnlog_rates"> <p> This is the homepage of the rate data crew: <tt><url url="http://sourceforge.net/projects/rates4linux"></tt>. There you can download the latest rate files (which change very frequently), or have a look at the latest rate news. There is also a mailing list available for this kind of stuff. Subscribe by sending an email with subject "subscribe" to: <tt><htmlurl url="mailto:rates4linux-users-request@lists.sourceforge.net" name="rates4linux-users-request@lists.sourceforge.net"></tt> (send "help" in your subject to get instructions). To write to the mailing list, send an email to: <tt><htmlurl url="mailto:rates4linux-users@lists.sourceforge.net" name="rates4linux-users@lists.sourceforge.net"></tt>. <sect1> isdnlog_servicetype: Can I see the service type from an incoming call in the output from isdnrep? <label id="isdnlog_servicetype"> <p> Andreas Kool <tt><htmlurl url="mailto:akool@Kool.f.EUnet.de" name="akool@Kool.f.EUnet.de"></tt> wrote on 3 Dec 1996: Indirectly in isdnrep, yes -- as soon as you enter an alias for the decoded service types in your &dquot;isdnlog.conf&dquot; ... <sect1> isdnlog_callerid1: Why don't I always receive from the German Telekom the number of a caller (&dquot;Caller ID&dquot;)? <label id="isdnlog_callerid1"> <p> For data privacy reasons, telephone numbers from the analog network are not transmitted unless the caller has explicitly allowed the Telekom to do so (costs nothing). Those with an ISDN connection, on the other hand, must explicitly deny permission for the Telekom to transmit the number, or apply to be able to do this on a call-by-call basis (CLIR). Call-by-call denial is free; call-by-call transmission costs extra. However, it seems to be <em>very</em> difficult for the Telekom to configure this correctly on the first try. If you depend on the transmission of Caller ID, you should check closely that everything is configured correctly. <sect1> isdnlog_callerid2: Do I receive the Caller ID from foreign calls (German Telekom)? <label id="isdnlog_callerid2"> <p> Yes, with calls from countries that don't view Caller ID quite as strictly as does Germany (e.g. USA, Canada). <sect1> isdnlog_spoofcallerid: I've heard that actually two Caller IDs are transmitted? <label id="isdnlog_spoofcallerid"> <p> That's right, there's one that is &dquot;User-Provided, not screened&dquot;, and the other is &dquot;Network-Provided&dquot; (from the telephone company). As the name says, the first one is provided by the user, whereas the second one is transmitted by the network. Providing a caller ID is only possible for a PBX connected in Point-to-point configuration with the feature &dquot;CLIP no screening&dquot;. <sect1> isdnlog_betterlogging: Why doesn't isdnlog record the number dialed by my other ISDN devices, since it records the charges? <label id="isdnlog_betterlogging"> <p> Because the ISDN card, like all ISDN device, has separate lines for sending and receiving (RX and TX lines). Isdnlog has to read data from the receiving line to learn the number dialed. This isn't possible, at least for the Teles cards, as Karsten Keil <tt><htmlurl url="mailto:keil@isdn4linux.de" name="keil@isdn4linux.de"></tt> wrote on 12 Feb 1997: <quote> This is the case for all cards with 1 Siemens ISAX; it has (and needs) only 1 sender and 1 receiver. Theoretically, it's possible to read the entire D channel with just one receiver (even with the ISAC); the D bits from the RX line are copied (somewhat delayed) to the TX line, over which the access control (collision recognition) of the SO bus takes place. Unfortunately with the ISAC it's not possible to read the echo bits in TA mode from a register. </quote> See the next questions for a possible solution. <sect1> isdnlog_reversedcard: How can I get isdnlog to also show the telephone numbers for other ISDN devices? <label id="isdnlog_reversedcard"> <p> There are several possibilities. <itemize> <item> COLP: First, the German Telekom offers the service COLP (Connected Line Identification Presentation, ca. DM 10 per month per basic line) that returns all data sent. This can then be read by isdnlog (=2.52) from the TX line. <item> Reversed card/dual mode: Alternatively, isdnlog offers the possibility to work with a second &dquot;re-poled&dquot; ISDN card. &dquot;re-poled&dquot; means that the RX line is connected to the TX connection of the card; the RX line of the card should not be connected to any line! (even if other documents might tell you something else). Because of this setup, this ISDN card cannot be used for anything else. This is called a reversed card, or the dual mode. The whole thing looks something like this: <verb> 3 -- RX+ 2a ---------------\ ISDN 4 -- TX+ 1a -- open ------------ ISDN bus 5 -- TX- 1b -- open ------------ card 6 -- RX- 2b ---------------/ </verb> Please note that this only works when the second card is an ISAC based cards (e.g. old Teles cards, Fritz! classic), since it requires a special bug/feature of that chip. All other cards, like IPAC based cards (e.g. ELSA QS1000pro) will not work in the role of a re-poled card. Please note that this will only work on the standard BRI interface, since for the more expensive PRI interface no card is available which can be used (PRI is a point-to-point connection anyway). <item> HFC cards: some HFC-PCI based cards allow a special feature where one of the B channels can be sacrificed in exchange for reading the complete D channel protocol - with just one single card. This is also supported by isdn4linux. Set the HFC card in the following way: <code> hisaxctrl <driver_id> 1 4 hisaxctrl <driver_id> 10 1 hisaxctrl <driver_id> 12 1 </code> You have to give isdnlog the command line option '-1' so that it makes use of the HFC option. Please note that a plain HFC-S does not work for hardware reasons, it has to be a newer one. If your card works with Hisax type 35 or 37, then it should work. Please also note that there is no known card for logging on a PRI interface in this way (also, the PRI interface is point-to-point, therefore only one device can be connected). <item> PBX: A third (theoretical) possibility exists for those who have their own PBX to which the other devices are connected. If the PBX can protocol all outgoing calls, this can be read (usually over a serial port). There is a reason why isdnlog has not support for this until now. To evaluate this data, isdnlog has to be able to access the date immediately after the RELEASE COMPLETE, before any new data is sent on the D channel. The PBXs tested up to now have all been too slow (in particular the widely used ISTEC). The only possibility is to combine the data afterwards. But then there are problems with synchronizing the different times. Whoever want to attempt to do this is welcome (I'll make the logs from my Ackermann Euracom available - Matthias Hessler <tt><htmlurl url="mailto:hessler@wi-inf.uni-essen.de" name="hessler@wi-inf.uni-essen.de"></tt>). </itemize> <sect1> isdnlog_rategraphic: How can I display the data transfer rates graphically? <label id="isdnlog_rategraphic"> <p> You can use &dquot;xisdnload&dquot;. Clemens Perz <tt><htmlurl url="mailto:listperz@gwsnet.ttt.de" name="listperz@gwsnet.ttt.de"></tt> on 6 Feb 1997 knew of another possibility: On Sunsite I found a little tool for the console called netload, and apapted it for the ISDN interfaces. With it you can quite easily see the current traffic on the line. It can be found at: <tt><url url="ftp://ftp.region.trier.de/pub/unix/linux/sources/network/isdn/netload-0.92.isdn.tar.gz"></tt> Simply start with <tt>netload isdnxx</tt>. <sect1> isdnlog_2callerid: Isdnlog (=2.52) shows for a caller <em>two</em> telephone numbers! Which one is correct? <label id="isdnlog_2callerid"> <p> The caller has most likely activated the (costly) feature CLIP (= Calling Line Identification Presentation, no screening), which means any telephone number can be transmitted. See the question &dquot;I've heard that actually two Caller IDs are transmitted?&dquot;. Andreas Kool <tt><htmlurl url="mailto:akool@Kool.f.EUnet.de" name="akool@Kool.f.EUnet.de"></tt> wrote on 26 Jan 1997: In any case, you can only fool software/PBXs that do not evaluate the screening indicator - isdnlog with version 2.52 shows both the correct *and* the faked telephone number. 'CLIP, no screening' was actually designed for transmitting internal company numbers in the public network. <sect1> isdnlog_soundbusy: I've set up a script to play sound per cat on /dev/sound or some other device. When several events occur, then there is an error: <tt>Can't open output file '/dev/sound': Device or resource busy</tt> <label id="isdnlog_soundbusy"> <p> Only one process at a time can access the sound device. You need an upper instance that coordinates access to the sound device. NAS (network audio system), and rplay can be used for this. <sect1> isdnlog_noshell: Isdnlog should call a program with redirected output (e.g. <tt>play anruf.au 2/dev/null</tt>). Why does ISDN tell me <tt>Can't start '/usr/local/bin/play anruf.au 2/dev/null' with execvp()</tt>? <label id="isdnlog_noshell"> <p> Because isdnlog is not a (Bourne) shell ;-) Isdnlog can only start <bf>real</bf> programs. Just write a little script for it and make it executable (chmod +x): <code> #!/bin/sh /usr/local/bin/play anruf.au 2/dev/null </code> <sect1> isdnlog_blankscreen: When dialing out, the screen goes momentarily black? <label id="isdnlog_blankscreen"> <p> This may happen when you start isdnlog with the options <tt>-t1</tt> or <tt>-t2</tt>, then the time is synchronized with the digital switching station. The screen saver thinks that more than x minutes have passed, which causes a short blackout of the screen. <sect1> isdnlog_nologging: Isdnlog does not log any incoming call for me? <label id="isdnlog_nologging"> <p> Please verify whether your setup complies with the restrictions given in the isdnlog man page: Isdnlog only works with the HiSax isdn driver. Other cards with their own driver are not supported. Additionally you need to enable d-channel logging (you can use "hisaxctrl <DriverId> 1 4" to do that, e.g. "hisaxctrl line0 1 4"). Isdnlog can only log outgoing calls that originate from your isdn card, and incoming calls. To get information about outgoing calls from other isdn devices (e.g. telephones), you need a second Teles isdn card, with crossed lines. Such a card is not usable for communicating, but can log outgoing calls from any device. See also question <ref id="isdnlog_reversedcard" name="isdnlog_reversedcard"> for using two ISDN cards for logging. <!-- Audio --> <sect> audio: Handling Voice with ISDN <label id="audio"> <p> (Most of the answers you will find here are taken from the - now unfortunately outdated - vbox manual by Matthias Hessler <tt><htmlurl url="mailto:hessler@isdn4linux.de" name="hessler@isdn4linux.de"></tt> and Bernhard Hailer <tt><htmlurl url="mailto:dl4mhk@lrz.uni-muenchen.de" name="dl4mhk@lrz.uni-muenchen.de"></tt>; you can get the manual at: <tt><url url="http://www.lrz-muenchen.de/˜ui161ab/www/isdn/"></tt> - click on &dquot;Audio!&dquot; (still in German we're afraid - sorry...) They are currently very outdated, but may give you a few hints? A newer place has now come up as a place for further vbox development. Please check it out: <tt><url url="http://innominate.org/projects/vbox/index.php3"></tt> <sect1> audio_links: Where can I find helpful links regarding vbox? <label id="audio_links"> <p> There are several scripts available to be used in connection to vbox, but the author is not up to date. Here is the latest one I received information about: <tt><url url="http://innominate.org/projects/vbox/index.php3"></tt> Please send me information if you know more helpful links, or howtos, or whatever useful... Also please note the documentation in the kernel source package: <tt>/usr/src/linux/Documentation/isdn/README.audio</tt> <sect1> audio_format: What is the format of the audio messages (.msg) vbox plays when it answers a call? <label id="audio_format"> <p> You can get the format from the messages with rmdgetheader. The samples messages in the packages are recorded using format 4 (the latest Zyxel-Compression) <sect1> audio_recordmsg: How can I record my own messages for vboxgetty? <label id="audio_recordmsg"> <p> First call yourself on the number you configured vboxgetty to answer and leave a message. Then rename the message to *.msg (standard.msg for the main answering message) and copy it to the directory where all the messages are kept (usually /var/spool/vbox/user/messages where user is the user for which vboxgetty is configured). You can also record a message using a microphone and the soundcard. <sect1> audio_play: How can I play audio messages locally using /dev/audio? <label id="audio_play"> <p> This is best achieved with vbox using format 6 (uLaw - must be compiled in). You can then easily play the messages using: <code> cat xxx /dev/audio </code> where xxx is the message-file. <sect1> audio_convertto: How can I convert audio messages which where recorded by vbox to other formats (i.e. from uLaw to WAV)? <label id="audio_convertto"> <p> The standard tool for converting all sound formats is SOX. SOX is available as source code for both UNIX and DOS. You can get it at: <tt><url url="http://www.powerweb.de/mpeg/util/msdos/sox10c.zip"></tt> (including sources that compile under Linux). <sect1> audio_convertfrom: How can I format WAV for uLaw (for my vbox announcement message)? <label id="audio_convertfrom"> <p> We receive the following tip form Christian Stueble <tt><htmlurl url="mailto:stueble@ls6.informatik.uni-dortmund.de" name="stueble@ls6.informatik.uni-dortmund.de"></tt> on 15 Jan 1997: For me, the following (somewhat indirect) method works: <code> sox file.wav -r 8000 file.ul rate rmdcatheader -u file.ul file.msg cat file.ul file.msg </code> It could be that you have to give different parameters to sox. As a first test you can try file.msg /dev/audio, you should be able to hear something. <sect1> audio_dtmf: How can I improve the recognition of (DTMF) dial tones? <label id="audio_dtmf"> <p> You can adjust the parameters DTMF_TRESH, SILENCE_TRESH, and H2_TRESH in file <tt>linux/drivers/isdn/isdn_audio.c</tt>. A DTMF tone is recognized if the amplitude of the correct frequency is larger than DTMF_TRESH and the amplitude of the second harmonian frequency is smaller than H2_TRESH. If a dial tone is recognized when no dialing took place, try to increase DTMF_TRESH and/or decrease H2_TRESH. However, test with many telephones - the current parameters were already set after some tuning. <!-- Audio Troubleshooting --> <sect1> audio_e0265: My vboxgetty gets a modem timeout, and reports error E0265. <label id="audio_e0265"> <p> Probably you need a patch that has been posted recently (8th December 1999) on the mailing list. <sect1> audio_noanswer: My vboxgetty does not answer any incoming calls. <label id="audio_noanswer"> <p> vboxgetty needs &dquot;.vboxrc&dquot; in the home directory of the user for which vboxgetty is configured. The number of rings is taken from this file. <sect1> audio_nocat: If vboxgetty has recorded a message in a format which can not be played using &dquot;cat xxx/dev/audio&dquot; how can I still hear the message? <label id="audio_nocat"> <p> Vboxgetty can play all formats. You can copy the message as the standard message (standard.msg in the messages directory) and call yourself, the message will be played then. (Don't forget to copy back the original message when you are done :-) ). See question <ref id="audio_recordmsg" name="audio_recordmsg">. <sect1> audio_earlyrecording: At the beginning of a message recorded by vboxgetty, there's often a part of my own announcement? <label id="audio_earlyrecording"> <p> This is a known bug that occurs when switching between the playing of the announcement and recording the message. Up to now there is no known workaround. <!-- Countryspecific pecularities --> <sect> Supported Countries <label id="countries"> <sect1> country_which: In which countries does isdn4linux work? <label id="country_which"> <p> We are aware of at least the following countries: <itemize> <item>Austria (see question <ref id="country_austria" name="country_austria">) <item>Australia <item>Brazil (see question <ref id="country_brazil" name="country_brazil">) <item>Belgium <item>Denmark <item>Finland <item>France (see question <ref id="country_france" name="country_france">) <item>Germany <item>Hungary <item>India <item>Ireland <item>Israel <item>Italy (see question <ref id="country_italy" name="country_italy">) <item>Japan <item>Luxemburg <item>Norway <item>Pakistan (see question <ref id="country_pakistan" name="country_pakistan">) <item>Peru <item>Poland <item>Portugal (see question <ref id="country_portugal" name="country_portugal">) <item>Singapore <item>Spain <item>Sweden <item>Switzerland (see question <ref id="country_switzerland" name="country_switzerland">) <item>The Netherlands (see question <ref id="country_netherlands" name="country_netherlands">) <item>United Arab Emirates <item>United Kingdom (see question <ref id="country_uk" name="country_uk">) <item>USA (see question <ref id="country_northamerica" name="country_northamerica">) </itemize> If your country is not on this list does not mean it is not supported. It just means we have not seen a confirmation about its usage there. Check the mailing list for other users from your country. <sect1> country_certified: Is isdn4linux approved for use by the telecommunications authorities? <label id="country_certified"> <p> That depends on the driver used, and your country. We only have information about Germany (send me information if you have information about other countries). However, that covers most other European countries as well, since a certification in one EC country has to be accepted in all others. These drivers are certified for use in Germany: <itemize> <item>Active cards: the approval covers the entire card including its firmware. Thus the approval also covers the use of these cards with isdn4linux. <item>Elsa Quickstep series cards (new name Microlink PCI) <item>Eicon Diva 2.01 PCI <item>Teles 16.3 ISA (with Siemens chipset) <item>Sedlbauer Speedfax+ PCI <item>Passive cards: all cards based on the HFC-S chipset. </itemize> Actually, since April 2000 the rules for certification have changed. Now the producer of an ISDN card has to do only hardware tests, the driver is not part of the certification anymore. This applies to the whole European Community. <sect> 1tr6: German Pecularities for 1TR6 <label id="1tr6"> <sect1> 1tr6_eaz: Which EAZ should I use for i4l? <label id="1tr6_eaz"> <p> You can use all available EAZ. However, two EAZ have a special meaning and can cause problems: <verb> EAZ 0: global call (all telephones ring) EAZ 9: global call (no telephone rings) </verb> Gernot Zander <tt><htmlurl url="mailto:hifi@scorpio.in-berlin.de" name="hifi@scorpio.in-berlin.de"></tt> wrote about this on 6. Jan 1997: <quote> I would not use 0, for my taste it is too likely that i4l will steal all voice connections. </quote> <sect1> 1tr6_extension: I use 1TR6 on an extension - the extension number has more than one digit (e.g. 206). What is my EAZ? <label id="1tr6_extension"> <p> Jens Ey <tt><htmlurl url="mailto:jens@jeyhh.shnet.org" name="jens@jeyhh.shnet.org"></tt> wrote on 10 Jan 1997: The EAZ for extensions is usuAlly the last digit of the extension number. As EAZ for the Linux computer you should then enter a '6'. <sect1> 1tr6_spv: What is a SPV? <label id="1tr6_spv"> <p> SPV stands for &dquot;semipermanente Verbindung&dquot; (semipermanent connection) and is a (soon to be obsolete) speciality of the German Telekom. Like a leased line, the calling partner is fixed, however the connection is only established as needed (which occurs very quickly, much quicker that a dial connection). Since the Telekom can use the line for other things when it's not needed, the SPV is cheaper than a leased line. This SPV is not to be confused with the Austrian understanding of SPV. The Austrian `SPV' has one channel leased line, and one channel for dialing. <sect1> 1tr6_spvdial: Does isdn4linux support SPVs? How? <label id="1tr6_spvdial"> <p> To switch on the support for SPVs, add an &dquot;S&dquot; before the number to be dialed. This works (quite well) for modem emulations as well as for defined network interfaces. <sect> Other countries <sect1> country_austria: Austria: We have neither an MSN nor an EAZ, only a normal plain telephone number. What do we have to use for i4l? <label id="country_austria"> <p> In Austria ISDN lines are by standard installed <em>without</em> MSN (which is different from Germany). That means when somebody calls the installed ISDN number the called party gets signalled a &dquot;global call&dquot;. i4l then says &dquot;incoming call without CPN&dquot; - &dquot;CPN&dquot; means called party number. Solution: Set the incoming &dquot;MSN&dquot; (in reality: none) to &dquot;0&dquot;, then i4l responds to the global call. Otherwise it waits for the signalling of the number you told i4l, and that won't happen (happens only for *additional* MSN). The same applies to the setup of your getty. On the other hand you should set the outgoing MSN correctly (without area code) -- however, a wrong MSN will be replaced with the correct one by your telecommunications provider. <sect1> country_brazil: Brazil: How does our MSN look like? <label id="country_brazil"> <p> For use with Telemar you have to configure your MSN as your phone number without the leading area code. Brazil is using EuroISDN. The ISDN service DVI which was launched by Telemar is based on a hardware solution from Teles (BRI PCI card), which has to be configured as NETjet card. However, since this card is very incompatible to the motherboards sold in Brazil, Telemar also offers the option of a Teles 16.3c ISA. You may be able to find some configuration help on <url url="http://www.olinux.com.br"> for this card. <sect1> country_france: France: How does our MSN look like? <label id="country_france"> <p> If you don't have MSN, you need to specify as local number only the last 4 digits of you phone number. A good thing is that you can also use sub-addressing. If your phone number is 01 41 33 67 87, and you want to use sub-address 02, then configure the local phone number of the HiSax driver as 6787.02 . <sect1> country_italy: Italy: What does our MSN look like? <label id="country_italy"> <p> isdn4linux also works in Italy (ICN card). The MSN must be the phone number with the Italian area code, and since middle of 2001 includes the leading 0. For example, if my phone number is 72004681 and my area code is 045, my MSN is 04572004681. Now with the setting AT&E04572004681 isdn4linux works fine. <sect1> country_netherlands: Netherlands: What does our MSN look like? <label id="country_netherlands"> <p> In The Netherlands the MSN includes (as opposed to the German Telekom) <em>also the area code</em> - but without the leading zero. <sect1> country_northamerica: North America: Can we use isdn4linux in North America? <label id="country_northamerica"> <p> Yes, you can use isdn4linux in North America. However, some specialties apply. In North America the telephone company will only provide a U instead of an S interface. This means that the customer rather than the telephone company has to supply the network terminator (NT-1). Your easiest solution is a card which has an integrated NT-1 and supports the U interface. Alternatively buy an external NT which translates between U and S interface, and connect your ISDN card with S interface (without NT-1) to it. In North America the channel protocol NI-1 is being used. NI-1 is related to DSS1 (both are Q.931 Protocols), but both have totally different groups of functions. Support for NI-1 has recently been added to HiSax, the driver for passive cards, with great help from Traverse Technologies: <tt><url url="http://www.ttcomms.com"></tt>. Since they helped to implement and verify NI-1 usability, we would recommend you buy their card NETspider-U (with integrated NT-1), as a thank-you for their contribution to isdn4linux open source development. See Documentation/isdn/README.HiSax for details on how to set up your system with HiSax (protocol type is 4, give SPID together with your own number in the form of <OWNNUMBER>:<SPID>). Quite some time ago, the firm &dquot;Spellcaster&dquot; has written their own isdn4linux driver for their (active) cards. Both BRI and PRI cards are available. More information is available on: <tt><url url="http://www.spellcast.com"></tt> Also, the active Eicon DIVA cards work fine in North America and have 5ESS and NI drivers, which are currently ported to UltraSparc. <sect1> country_pakistan: Pakistan: What should we use as MSN? <label id="country_pakistan"> <p> It seems that no MSN functionality is supported. Therefore the MSN should be set to &dquot;0&dquot;. <sect1> country_portugal: Portugal: What should we use as MSN? <label id="country_portugal"> <p> As long as only one telephone number or MSN was applied for, the telephone company sends no caller ID. Therefore the MSN should be set to &dquot;0&dquot;. If more than one MSNs was applied for, then these should be set as usual. <sect1> country_switzerland: Switzerland: We have neither an MSN nor an EAZ, just a plain telephone number. What do we have to use for i4l? <label id="country_switzerland"> <p> In Switzerland usually you have to use the telephone number without area code. For old ISDN numbers where you have been assigned ten numbers in a row this may be different; in that case use the <em>last digit</em> of your telephone number as your MSN/EAZ (&dquot;6&dquot; if you have the telephone number &dquot;123456&dquot;). <sect1> country_uk: UK: What should we use as MSN? <label id="country_uk"> <p> It depends on your ISDN option. <itemize> <item> ISDN: Does not allow normal MSNs in UK. Each MSN is actually a single digit, 0 - 9, corresponding to the last digit of the actual phone number. You either have *no* MSNs (then configure isdn4linux to use '0' as MSN, e.g. with <tt>AT&E0</tt>), or 10 MSNs; you then always get a block of 10 sequential telephone numbers (xxx0-xxx9), of which the last digit (0-9) is your MSN (0 is used in case you use an invalid number). <item> ISDN2e: Seems to be normal EuroISDN. You are assigned MSNs which you can use and configure for isdn4linux. The MSN is reported to consist of the last 6 digits of your telephone number (try to add digits from your area code, if the local number part is shorter than 6 digits). <item> BTHH (BT HomeHighway): additionally to 2 ISDN ports it includes two analog lines with separate telephone number - but calls to and fro for those won't be signalled on the ISDN line, even so they use up a B-channel. Additional MSN are NOT available (therefore use '0' as MSN to configure isdn4linux). Charge info is possible for extra cost. Configure isdn4linux only with your 'digital number' as MSN. <item> BTBH (BT BusinessHighway): The additional paperwork including a credit-check enables you to get MSNs and other extras for extra cost. Otherwise pretty much like BTHH. Configure isdn4linux to use your 'digital number' and/or your MSNs. </itemize> Please note that BT offers an unexpected special "feature" on international calls. For international data calls you have to dial 000<country_code> (three zeros), rather than the 00<country_code> (two zeros) for international voice calls. By the way: for a BT Speedway card try to select AVM Fritz card (either ISA or PCI - depends on what you got; see question <ref id="hardware_fritz" name="hardware_fritz">). Since about November 2001, all BT home highway and possibly Business Highway NTE boxes come with a built in USB terminal adapter. This terminal adapter is based on the ST-5481 chipset. Load the module st5481 for this device, then set up your isdn configuration with isdnctrl. Also, check out <url url="http://www.wurtel.cistron.nl/i4l-howto-uk.html">. <sect> misc: Miscellaneous <label id="misc"> <sect1> misc_standards: Which standards apply to the ISDN protocol layers? <label id="misc_standards"> <p> These are the main standards: <itemize> <item> Layer 1: ITU I.430 and ETSI 300 012-1 <item> Layer 2: ITU Q.921 and ETSI 300 125-1 <item> Layer 3: ITU Q.931 and ETSI 300 102-1 (plus some changes and clarifications in ETSI 300 403) </itemize> All layers are also described in TBR3. For study, the standards are freely available from <url url="http://www.etsi.org">. <sect1> misc_nonullcable: Can I connect two ISDN devices directly with a kind of &dquot;null modem cable&dquot;? <label id="misc_nonullcable"> <p> This is only possible if one of the cable can run in NT mode (see glossary on what this is: <ref id="glossary_ntmode" name="glossary_ntmode">). Only a few cards allow it, all others need an NTBA or PBX with an internal bus to communicate with each other. See question <ref id="feature_crossedcable" name="feature_crossedcable">. <sect1> misc_uisdn: Can isdn4linux run in parallel to UISDN? <label id="misc_uisdn"> <p> Yes. Both ISDN packages load the module isdn.o, otherwise the naming conventions are different. Tip: rename Urlichs isdn.o to uisdn.o, and change lib/modules/modules.isdn (or whatever the file is called that lists the modules and is read by the script) accordingly. Happily the default names of the ISDN devices are also different. <!-- Glossary --> <sect> glossary: ISDN specific words which are used in this FAQ <label id="glossary"> <p> <descrip> <tag/active card/ <label id="glossary_active"> Cards can come in different versions: passive, semi-active, active. Active cards handle the D-channel and B-channel protocol in their hardware. The extra hardware makes them more expensive, but better suited to use where a low CPU usage is needed (e.g. when having many ISDN cards in one computer). Because of their special hardware, a special driver is required. Depending on the hardware/driver, special tasks like sending/receiving analog G3 faxes may be very easy to implement - if you need these features, get one of them. <tag/AOC-D/ &dquot;Advice Of Charge During the Call&dquot;. <tag/AOC-E/ &dquot;Advice of Charge at the End of the Call&dquot;. In Germany, this service is included in the &dquot;Komfort&dquot; connection. <tag/BRI/ BRI means basic rate interface and is the most commonly used interface. In Europe, a BRI includes 2 B-channels for data communication, and 1 D-channel for administration of the data communication. The alternative is a PRI interface. <tag/CLIP/ CLIP (Calling Line Identification Presentation) can be offered by the ISDN provider. When you call somebody, then your telephone number will be transmitted to the other phone. The opposite of CLIP is CLIR. In Germany, CLIP is the default. <tag/CLIR/ CLIR (Calling Line Identification Restriction) can be offered by the ISDN provider: one can (from call to call) restrict the identification of one's own caller ID to the other party. The opposite of CLIR is CLIP. In Germany, this must be applied for but is without charge (however call by call transmission of the caller ID costs extra). <tag/COLP/ COLP (Connected Line Identification Presentation) can also be offered by the ISDN provider. If you've applied for COLP, you get an extended dialing protocol. You will receive feedback from your telecommunication company who picked up your outgoing call. Normally, you will get the same number as you dialed beforehand; however, with call diversion this could also be a different number. In Germany, it must be applied for, and costs extra. More information than COLP can be obtained with the help of a reverse-connected ISDN card. <tag/CVS Tree/ The i4l developers have formed a team. The tool CVS allows the members to easily make patches. The history of the project is also thereby documented, and it is also not difficult to reproduce older versions. <tag/EAZ/ This is a German name for an MSN. In Germany, EAZ and MSN are used as synonyms, though in theory one ought to differentiate according to the protocol used. That which is called MSN in the Euro-ISDN protocol was called EAZ in the German 1TR6-ISDN protocol (a German predecessor to Euro-ISDN). <tag/HDLC/ A widely used low-level protocol, usually used to connect your computer with your internet provider. To connect to a computer mailbox, usually X.75 is being used. <tag/HSCX/ A Siemens chip which is, similar to ISAC, on many passive cards. It takes over the serial bus from ISAC and demultiplexes when receiving or multiplexes (i.e. inserts the bits in the correct position) the B channels. <tag/ISAC/ A Siemens chip which is, similar to HSCX, on many passive cards. It is responsible for Level 1, so it sits (almost) directly on the line. It handles the D channel protocol and sends the S0 data to a special serial bus (IOM). When sending it does the opposite. <tag/leased line/ <label id="glossary_leased"> Your telecommunication company can hardwire the connection between two of their ISDN users. Then these users are always connected to each other without dialing and can not dial out to someone else any more. <tag/MSN/ Unlike a normal telephone connection, an ISDN connection can have more than one telephone number - each of these is called an MSN (Multiple Subscriber Number). <tag/NT/ NT is the abbreviation of network terminator. This is the interface between an ISDN user and the ISDN provider. It is a small hardware box to which the user has to connect his ISDN devices via a so called S0 interface. In most European countries, the ISDN provider supplies the NT. A user in North America usually has to buy one, therefore the NT is often integrated into the ISDN card there. <tag/NT mode/ <label id="glossary_ntmode"> When multiple devices are connected to the ISDN connection, then all user device behave as slaves, where the network terminator (NT) behaves as master and synchronizes the communication on the S0 bus. The special behavior of the network terminator is called NT mode. User devices are normally not capable of running in NT mode. As a result, user devices can not communicate with each other even when they are connected via a crossed cable. Only some special ISDN cards (HFC chipset) are capable of running in NT mode, and can directly communicate with other ISDN user devices via a crossed cable. <tag/multi-device mode/ <label id="glossary_multidevicemode"> Your ISDN interface can be configured either in multi-device mode (in German: Mehrgeraeteanschluss), or in point-to-point mode (in German: Anlagenanschluss). The multi-device mode is the normal connection mode for private ISDN users or very small business users. The user can attach multiple devices to the ISDN connection. The ISDN provider will assign a small number of fixed telephone numbers (usually up to 10 MSN), if any, to the ISDN connection. <tag/passive card/ <label id="glossary_passive"> Cards can come in different versions: passive, semi-active, active. Passive cards handle the D-channel and B-channel protocol in software. This makes them least expensive, but only suitable where the CPU is able to do the additional work (for normal data communication any computer starting from a 486 or even a 386 should be able to handle one or two cards). Since only a few hardware chips are in wide usage, a generic driver, HiSax, can handle almost all passive cards. <tag/PBX/ A PBX (Private Branch eXchange) is used to connect different internal devices to the ISDN network. This is usually for analog devices that cannot be directly connected to an ISDN network. The PBX can also make an internal digital S0 bus available, on which ISDN devices can be connected. This allows for local calls without using the switching station (thereby avoiding the charges from your telephone company). <tag/point-to-point mode/ <label id="glossary_pointtopointmode"> Your ISDN interface can be configured either in multi-device mode (in German: Mehrgeraeteanschluss), or in point-to-point mode (in German: Anlagenanschluss). The point-to-point mode is the normal connection mode for business ISDN users. The user can attach only one single devices to the ISDN connection which will have to handle all calls (typically a PBX will be used). The ISDN provider will assign a range of numbers to the ISDN connection. Any call within this number range will be sent to the user. The ISDN provider will leave assignment of the last digits of the telephone number to the ISDN user. This setup usually allows for additional features, but is also more expensive. <tag/PRI/ PRI means primary rate interface and is the used when a single or multiple BRI are not sufficient in bandwidth. In Europe, a PRI includes 30 B-channels for data communication, and 1 D-channel for administration of the data communication. <tag/semi-active card/ <label id="glossary_semiactive"> Cards can come in different versions: passive, semi-active, active. For semi-active cards there is no fixed definition, so here is what we think: semi-active cards handle the B-channel protocol in their hardware with special DSP (digital signal processor) support, but they leave the D-channel protocol to the software. This makes them better suitable to special tasks like sending/receiving analog G3 faxes. Because of their special hardware, a special driver is required. Be aware, that for marketing reasons some cards are called semi-active when in fact they are passive (e.g.: Teleint). <tag/subaddressing/ When dialing, it is possible to provide an additional number, the subaddresss. The subaddress is transmitted to the remote side, and allows it to react on it. This feature may not be available, at least not for free (with the exception of France). <tag/TEI/ TEI stands for Terminal End Identifier. The local switching station, or with an internal S0 the PBX, automatically or permanently assigns each end device a TEI. This simply allows the addressing of the D channels. TEIs have the following values: 0-63 = permanent TEIs (e.g. 0 is used for point to point connections) 64-126 = automatically assigned 127 = broadcast to all devices (e.g. an incoming call) <tag/UUS/ UUS is user to user signalling. It means, that when placing a call, a few bytes of user-specific data can be transmitted along with the call setup frame. This feature has been abused in the past in Germany, causing the local exchanges to run out of available channels (the call setup causes them to reserve a B-channel). Since then, this feature usually costs extra and there is a data limit on it (depends on your ISDN provider). Have a look at the usage condition, in short it's only allowed to use this feature, if indeed you want to setup a call. Please note that it has been reported that some buggy PBX (like ISTEC 1003) may refuse a connection when support of UUS is signalled to them. <tag/X.75/ A widely used low-level protocol, usually used to connect your computer with a computer mailbox. For connections to the internet, HDLC is usually used. </descrip> </article>