FAQ for isdn4linux

Matthias Hessler ( hessler@isdn4linux.de)

1. general: General information about isdn4linux

• 1.1 general_i4l: What is isdn4linux?
• 1.2 general_hardware: What hardware is supported by isdn4linux?
• 1.3 general_features: What features are supported by isdn4linux?
• 1.4 general_countries: Which countries are supported by isdn4linux?
• 1.5 general_docu: Where do I find more documentation, how-to's, helpful tips & tricks?
• 1.6 general_getlatest: Where do I get the latest version of isdn4linux?
• 1.7 general_contacts: How can I get in contact with the developers?

2. distrib: Distribution

• 2.1 distrib_getlatest: How can I get the latest isdn4linux?
• 2.2 distrib_cvs: How can I access the source from the current development/what is the CVS tree all about?

3. Features

• 3.1 feature_not: Which ISDN features cannot be offered by isdn4linux?
• 3.2 feature_data: Which ISDN data transmission modes are supported?
• 3.3 feature_voice: Can I use isdn4linux as an answering machine?
• 3.4 feature_fax: Can I fax with isdn4linux?
• 3.5 feature_divert: Is it possible to initiate call forwarding with i4l?
• 3.6 feature_ipx: Can I route ipx/spx over ISDN with Linux?
• 3.7 feature_2channel: Does isdn4linux support channel bundling?
• 3.8 feature_diald: Can I combine isdn4linux with diald?
• 3.9 feature_dod: Does the driver support "dial on demand"?
• 3.10 feature_sms: Can I send SMS (short messages) to my handy via ISDN?
• 3.11 feature_btx: Is the German videotex/Btx/Datex-J possible with isdn4linux?
• 3.12 feature_clock: How can I set the clock of my computer with ISDN?
• 3.13 feature_dosemu: Can I use isdn4linux under dosemu?
• 3.14 feature_capi: Is there a CAPI interface available?
• 3.15 feature_uus: Is UUS (user to user signaling) supported?
• 3.16 feature_subaddressing: Is subaddressing supported?
• 3.17 feature_gmsv110: Can I connect from my PDA via GMS cellular phone to isdn4linux?
• 3.18 feature_future: Which features are planned for the future?

4. docu: Documentation, Howto's, Tips & Tricks, Mailing List/Newsgroup

• 4.1 docu_first: What documents should I read first?
• 4.2 docu_website: Where is the official website for isdn4linux?
• 4.3 docu_newsgroup: Where is the newsgroup for isdn4linux?
• 4.4 docu_mailinglist: Where is the mailing list for isdn4linux?
• 4.5 docu_maillistdigest: How can I get a digest of the mailing list for isdn4linux (only one message per day)?
• 4.6 docu_mailarchive: Is there an archive of the isdn4linux mailing list?

5. hardware: Supported hardware, its specialities, and hardware-related problems

• 5.1 hardware_support: Which hardware is supported?
• 5.2 hardware_activepassive: What is the difference between an active and a passive ISDN card?
• 5.3 hardware_recommend: Which card is recommended by the developers?
• 5.4 hardware_external: Does isdn4linux support external terminal adapters?
• 5.5 hardware_cabeling: How should I wire my ISDN cables?
• 5.6 hardware_irq: Why should I avoid IRQ 12 and 15 for my ISDN card?
• 5.7 hardware_s2m: Which S2M cards are supported?
• 5.8 hardware_smp: Can I run isdn4linux on my multi-CPU board?
• 5.9 hardware_alpha: Can I run isdn4linux on a DEC Alpha with Linux?
• 5.10 hardware_ppc: Can I run isdn4linux on a PowerPC with Linux?
• 5.11 hardware_maxcards: How many ISDN cards can I put into my computer?
• 5.12 hardware_elsa: What should I know about ISDN cards from ELSA?
• 5.13 hardware_teles: What should I know about before buying an ISDN card from Teles?
• 5.14 hardware_avmb1: What is special about the AVM B1 card?
• 5.15 hardware_icn: What is special about the ICN card?
• 5.16 hardware_crossedcable1: If i4l uses one B-channel then the other one will be blocked (incoming as well as outgoing)...
• 5.17 hardware_crossedcable2: How can I test whether a a/b cable pair has been crossed?
• 5.18 hardware_pbx: i4l is connected to the internal bus of a PBX. Any problem?
• 5.19 hardware_telestrouble: The PNP tools done work with my Teles 16.3 PNP card!
• 5.20 hardware_elsacabletrouble: On my ELSA card, the LED for the loss of the TEI often blinks. My connections are also often disrupted...
• 5.21 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?

6. config: General information about Configuration

• 6.1 config_msn: How should I set up isdn4linux with my MSNs?
• 6.2 config_hardware: How should I configure my hardware? Is there something special I should know about my ISDN card?
• 6.3 config_dialout: How should I configure dialout?
• 6.4 config_suse: I can not select my card in yast?
• 6.5 config_pnp: How do I configure a PNP (Plug and Play) card?
• 6.6 config_kerneld: Why shouldn't I use kerneld to load the ISDN modules in the kernel as needed?
• 6.7 config_runlevel: How can I boot Linux sometimes with ISDN, and sometimes without?
• 6.8 config_manycards: How do I configure more than 1 ISDN card?
• 6.9 config_manychannels: How can I increase i4l's maximum number of channels?
• 6.10 config_gsmv110: How do I connect my PalmPilot via GSM over V.110 to my computer?
• 6.11 config_links: What helpful links are there about isdn4linux?

7. trouble: Troubleshooting

• 7.1 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.".
• 7.2 trouble_strategy: My isdn4linux doesn't work! How do I best go about finding the problem?
• 7.3 trouble_boot: How can I tell whether my ISDN card has been corrected recognized?
• 7.4 trouble_isdncause: I get an error message like "cause: E1234" (or similar)?
• 7.5 trouble_notelrings: Neither my telephone nor my fax machine ring when I call them with isdn4linux?
• 7.6 trouble_guestaccess: Are there sites that offer guest access where I can test my isdn4linux setup?
• 7.7 trouble_unload: I can't unload my ISDN modules ("isdn: Device or resource busy"), even so I closed all ISDN applications?
• 7.8 trouble_tcpdump: Why does my tcpdump not work for ip packets going over ISDN? How can I get a tcpdump patched for ISDN?
• 7.9 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?
• 7.10 trouble_lotsdebug: My hard disk becomes very active when isdn4linux run. How can I turn this off?
• 7.11 trouble_outofbuffers: I get messages like "HSCX RME out of buffers", "HSCX RFP out of buffers", "HSCX B EXIR 10" in the syslog?
• 7.12 trouble_noresetinit: After a soft reset, my card does not initialize correctly.
• 7.13 trouble_xosview: xosview doesn't show any network activity since installing i4l.
• 7.14 trouble_unknownhost: When I for example from a W95 box call up a page with Netscape, I only get the answer "unknown host".
• 7.15 trouble_noroute: Addresses are now found, but now I get "no route to host".
• 7.16 trouble_nolocalnet: After booting, my local network can no longer be reached. I use the network interface ippp0 with ifconfig 0.0.0.0; the default route points to ippp0.

8. msn: Configuration/MSNs

• 8.1 msn_my1: What is my MSN? What if I don't have any?
• 8.2 msn_my2: How can I find out how my telephone number is transmitted to the calling party?
• 8.3 msn_config: How do I configure my MSN?
• 8.4 msn_mindialin: How can I minimize usage of MSNs for digital data dialin?
• 8.5 msn_onlyone: How can I use one MSN for everything?
• 8.6 msn_buendel: Can I have several NTBAs, all with the same MSN?

9. lan: ISDN4LINUX in a LAN

• 9.1 lan_config: How can I set up Linux so that other computers in my LAN can access the internet via my Linux computer?
• 9.2 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)?

10. dialout: Configuration of Dial-Out

• 10.1 dialout_config: How do I configure dialout properly?
• 10.2 dialout_dialmode: When an IP packet should go over the link (which usually triggers a dialout), all I see in the log is: "dial rejected: interface not in dialmode auto"?
• 10.3 dialout_advanced: What special dialout features are available?
• 10.4 dialout_permission: How can I allow a normal user to initiate dialouts?
• 10.5 dialout_manycards: How do I configure dialout with more than 1 ISDN card?

11. pap: Authenticate properly (especially with PAP)

• 11.1 pap_optionauth: When dialing out, I get the message "pppd: peer authentication required but no authentication files accessible." What does this mean?
• 11.2 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: "sent (0) (LCP ConfReq id=0x1 mru 1500 auth pap magic 0xcd12e9c4"
• 11.3 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: "sent (0) (LCP ConfRej id=0x1 auth pap"
• 11.4 pap_checkpwd: How can I check which password is actually sent to the remote side?
• 11.5 pap_passwd: I have problems with PAP or CHAP authentication. It does not work although I'm sure I entered passwords etc. correctly.

12. syncppp: Sync PPP

• 12.1 syncppp_whichppp: pppd, ipppd, syncPPP, asyncPPP .. what is they? Which should I use?
• 12.2 syncppp_compile: How do I compile isdn4linux with syncPPP?
• 12.3 syncppp_netinterface: How should I name my network interface?
• 12.4 syncppp_config: How do I configure isdn4linux with syncPPP?
• 12.5 syncppp_busy: How can I tell if a connection is unsuccessful (busy)?
• 12.6 syncppp_logindelay: How can I reduce login delay?
• 12.7 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.
• 12.8 syncppp_pppbind: How does the (little-documented) "pppbind" command in isdnctrl work?
• 12.9 syncppp_dynip: I want to use dynamic IP address assignment. How must I configure the network device?
• 12.10 syncppp_ipx: How can I do IPX over ipppd?
• 12.11 syncppp_faster: How can I increase my PPP data transfer rates?
• 12.12 syncppp_compression: Which compressions can I use with ipppd?
• 12.13 syncppp_strategy: I can't get a connect. How can I find out where the problem is?
• 12.14 syncppp_log: How can I get a log for ipppd?
• 12.15 syncppp_nopppsupport: Starting ipppd I get the error message "this systems lacks ppp support".
• 12.16 syncppp_nousabledevice: When I try to start ipppd it says "Can't find usable ippp device"
• 12.17 syncppp_starterror: When I start ipppd, I only get error messages from the i4l driver.
• 12.18 syncppp_framesdelayed: I get the message IP frames delayed - but no connection.
• 12.19 syncppp_noroute: I cannot dial out with isdnctrl dial ippp0. It seems as if the route to ipppd is missing although I did set it (network unreachable). With my old kernel 2.0 everything works fine!
• 12.20 syncppp_nodefaultroute: After ipppd dials out my default route is gone.
• 12.21 syncppp_packettoolarge: I often get the error message hscx_empty_fifo: incoming packet too large
• 12.22 syncppp_slow: The connection with ipppd seems to work, but eventually it crashes or is very slow.
• 12.23 syncppp_loadproblem: I only have problems with ipppd when the connection is being heavily burdened. Then everything stops. What could be causing this?
• 12.24 syncppp_mtu: My ipppd works, but I keep getting the message pppd(104): ioctl(SIOCSIFMTU): Invalid argument"?
• 12.25 syncppp_1stpacket: The first IP packet gets lost on automatic dialout with dynamic IP address allocation.
• 12.26 syncppp_droppacket: What does the message "No phone number, packet dropped" mean?
• 12.27 syncppp_leadingzero: Why does my ipppd dial one too many zeros ("ippp0: dialing 0 089XXXXXX...")? I don't have any extensions!
• 12.28 syncppp_ethfake: My ISDN device is shown with HWaddr and IRQ=0 and base address = 0 when I list it with ifconfig

13. asyncppp: Configuration Async PPP

• 13.1 asyncppp_whichppp: pppd, ipppd, async PPP, sync PPP - what are they? Which should I use?
• 13.2 asyncppp_config: How do I configure async PPP?
• 13.3 asyncppp_logindelay: How can I reduce login delay?
• 13.4 asyncppp_fast: How can I increase my transfer rates with PPP?
• 13.5 asyncppp_log: How can I get a log for pppd?
• 13.6 asyncppp_suddendeath: Establishing the connection works fine, but pppd crashes just after that (i.e. the first bytes gets through, but then everything stops)

14. rawip: Raw IP

• 14.1 rawip_whatis: What is Raw IP, when should I use it?

15. ttyI: Configuration of the ttyI* devices (`Modem emulation')

• 15.1 ttyI_nomodem: Don't the ttyI* devices emulate an analog modem?
• 15.2 ttyI_dev: Which devices should I use for calls out or calls in?
• 15.3 ttyI_hdlc: How to I switch the modem emulation from X.75 to HDLC?
• 15.4 ttyI_uucp: How can I poll with Taylor-UUCP using isdn4linux?
• 15.5 ttyI_speed: What speed should I set for the ttyI* devices?
• 15.6 ttyI_nocarrier: When I dial with "ATD....." I always get a "NO CARRIER".
• 15.7 ttyI_noincall: My ttyI* device/pppd does not recognize an incoming call.
• 15.8 ttyI_callphone: Why can't I dial my telephone or fax from the ttyI* devices?
• 15.9 ttyI_noconnect: I can't get a connection to my ISDN mailbox/BBS.
• 15.10 ttyI_forcehangup: My modem emulation hangs. How can I force my card to hang up?
• 15.11 ttyI_channelclosed: During a tty connection, I get a message from the kernel: "teles_writebuf: channel not open". Then no more input is accepted for this connection.
• 15.12 ttyI_uucp: When I use UUCP with X.75, I always get transfer errors!

16. dod: Unwanted dialout on demand

• 16.1 dod_how: How does dialout on demand work?
• 16.2 dod_disaster: What is a charge unit disaster?
• 16.3 dod_causes: What can cause a charge unit disaster?
• 16.4 dod_off: How can I safely turn off dialout on demand?
• 16.5 dod_strategy: How can I track down unexplainable dialouts?
• 16.6 dod_winclient: Can it be that the Win95 machine on my LAN is causing automatic dialouts?
• 16.7 dod_localdns: I have set up a local DNS name server. Why does it cause unwanted dialouts? How can I find the cause?
• 16.8 dod_sendmail: How can I get sendmail to not initiate any connections without local mail being left undelivered?
• 16.9 dod_samba: The samba package always triggers dialouts for me. How can I prevent this?
• 16.10 dod_netscape: How can I get Netscape to quit initiating dialouts when starting?
• 16.11 dod_closeipconnect: After closing the line, I discover with netstat -nt that IP connections are still open. How can I close these manually?
• 16.12 dod_onlineoncrash: Is it possible that even with a crashed computer a ISDN connection remains open (and the charge units accumulate)?

17. chargeint: Chargeint

• 17.1 chargeint_whatis: What does Chargeint?
• 17.2 chargeint_config: How should I configure Chargeint?
• 17.3 chargeint_whennot: When does it not make sense to use the chargeint?
• 17.4 chargeint_correcttime: How can I be sure that the chargeint patch is using the correct time?
• 17.5 chargeint_nohangup: The connection doesn't end with timeout.

18. 2channel: Channel bundling (MPPP, raw bundling)

• 18.1 2channel_whatis: What is channel bundling and how can I use it?
• 18.2 2channel_raw: What is raw bundling?
• 18.3 2channel_rawconfig: How do I configure raw bundling?
• 18.4 2channel_rawgoodbad: What are the advantages and disadvantages of raw bundling?
• 18.5 2channel_mppp: What is MPPP?
• 18.6 2channel_mpppconfig: How do I configure MPPP?
• 18.7 2channel_mpppgoodbad: What are the advantages and disadvantages of MPPP?
• 18.8 2channel_mpppcompile: I tried MPPP but it doesn't work. The ipppd writes in the debug log something like: " ... 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 ..."

19. remote: Pecularities of the remote ISDN device

• 19.1 remote_win95: How do I configure Windows95 to dial successfully into my isdn4linux computer?
• 19.2 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?
• 19.3 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?
• 19.4 remote_cisco: How does isdn4linux work with a Cisco (HDLC) on the other side?
• 19.5 remote_ispa: What settings does ISPA etc. (DOS, Windows) need to work with the standard settings of isdn4linux?

20. leased: Leased lines

• 20.1 leased_nosignal: How does establishing and ending a connection work with D64S without signaling?
• 20.2 leased_hisaxconfig: With i4l, how do I configure my card on a D64 leased line?
• 20.3 leased_x75: How do I configure X.75 on a D64 leased line?
• 20.4 leased_splitline: With ISDN, can I use one channel as a leased line and other as a dialup line?

21. dialin: Configuration of a Dial-In Server

• 21.1 dialin_config: How can I enable others to login via ISDN?
• 21.2 dialin_manyparallel: How can I allow several people to call in to me at the same time?
• 21.3 dialin_hdlc: Someone would like to dial in to my mgetty with HDLC. Is ttyI1 correct, or do I have to start with ttyI0?
• 21.4 dialin_autoppp: Is it possible with mgetty to automatically start pppd when LCP frames are received?
• 21.5 dialin_passwd: How can I have (i)pppd check passwords from /etc/passwd instead of /etc/ppp/pap-secrets when someone dials in?
• 21.6 dialin_ignored: I keep getting the message "isdn_tty: call from XXX - YYY ignored". Why does isdn4linux (syncPPP) ignore this dialin attempt?
• 21.7 dialin_async: A SunISDN tries to dial into my i4l system.

22. callback: Callback

• 22.1 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.
• 22.2 callback_cisco: Somehow i4l can not callback a Cisco?
• 22.3 callback_ascend: Callback from an Ascend works only when I set "Active=Yes" in the Ascend menu; but then the Ascend keeps calling me, even when my machine is off.
• 22.4 callback_banzai: How can I callback a Banzai!?

23. isdnlog: Isdnlog

• 23.1 isdnlog_rates: Where do I get the latest rate information?
• 23.2 isdnlog_servicetype: Can I see the service type from an incoming call in the output from isdnrep?
• 23.3 isdnlog_callerid1: Why don't I always receive from the German Telekom the number of a caller ("Caller ID")?
• 23.4 isdnlog_callerid2: Do I receive the Caller ID from foreign calls (German Telekom)?
• 23.5 isdnlog_spoofcallerid: I've heard that actually two Caller IDs are transmitted?
• 23.6 isdnlog_betterlogging: Why doesn't isdnlog record the number dialed by my other ISDN devices, since it records the charges?
• 23.7 isdnlog_reversedcard: How can I get isdnlog to also show the telephone numbers for other ISDN devices?
• 23.8 isdnlog_rategraphic: How can I display the data transfer rates graphically?
• 23.9 isdnlog_2callerid: Isdnlog (=2.52) shows for a caller two telephone numbers! Which one is correct?
• 23.10 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: Can't open output file '/dev/sound': Device or resource busy
• 23.11 isdnlog_noshell: Isdnlog should call a program with redirected output (e.g. play anruf.au 2/dev/null). Why does ISDN tell me Can't start '/usr/local/bin/play anruf.au 2/dev/null' with execvp()?
• 23.12 isdnlog_blankscreen: When dialing out, the screen goes momentarily black?

24. audio: Handling Voice with ISDN

• 24.1 audio_format: What is the format of the audio messages (.msg) vbox plays when it answers a call?
• 24.2 audio_recordmsg: How can I record my own messages for vboxgetty?
• 24.3 audio_play: How can I play audio messages locally using /dev/audio?
• 24.4 audio_convertto: How can I convert audio messages which where recorded by vbox to other formats (i.e. from uLaw to WAV)?
• 24.5 audio_convertfrom: How can I format WAV for uLaw (for my vbox announcement message)?
• 24.6 audio_noanswer: My vboxgetty does not answer any incoming calls.
• 24.7 audio_nocat: If vboxgetty has recorded a message in a format which can not be played using "cat xxx/dev/audio" how can I still hear the message?
• 24.8 audio_earlyrecording: At the beginning of a message recorded by vboxgetty, there's often a part of my own announcement?

25. Supported Countries

• 25.1 country_which: In which countries does isdn4linux work?
• 25.2 country_certified: Is isdn4linux approved for use by the telecommunications authorities?

26. 1tr6: German Pecularities for 1TR6

• 26.1 1tr6_eaz: Which EAZ should I use for i4l?
• 26.2 1tr6_extension: I use 1TR6 on an extension - the extension number has more than one digit (e.g. 206). What is my EAZ?
• 26.3 1tr6_spv: What is a SPV?
• 26.4 1tr6_spvavailable: How long will there still be SPVs?
• 26.5 1tr6_spv: Does isdn4linux support SPVs? How?

27. Other countries

• 27.1 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?
• 27.2 country_france: France: How does our MSN look like?
• 27.3 country_italy: Italy: What does our MSN look like?
• 27.4 country_netherland: Netherlands: What does our MSN look like?
• 27.5 country_northamerica: North America: Can we use isdn4linux in North America?
• 27.6 country_portugal: Portugal: What should we use as MSN?
• 27.7 country_switherland: Switzerland: We have neither an MSN nor an EAZ, just a plain telephone number. What do we have to use for i4l?
• 27.8 country_uk: UK: What should we use as MSN?

28. misc: Miscellaneous

• 28.1 misc_ntbadip: Where can I find information on the dip switches of my German NTBA?
• 28.2 misc_nonullcable: Can I connect two ISDN devices directly with a kind of "null modem cable"?
• 28.3 misc_uisdn: Can isdn4linux run in parallel to UISDN?

29. glossary: ISDN specific words which are used in this FAQ