Chapter 9. ISDN Configuration

Revision History
Revision 0.22002-04-14EW
corrected and edited
Revision 0.12002-03-15EW
initial revision

Table of Contents

Step 1: Download and declare the isdn.lrp package
Step 2: download the isdn.o and the appropriate hisax.o modules
Step 3: declare the ISDN modules
Step 4: configure ISDN
Step 5: configure your interfaces file
Step 6: configure Shorewall


We assume here that you want to make a connection to the internet using synchroneous ppp and that you use an internal passive ISDN card. The isdn4linux driver is documented for Euro ISDN

The setup is tested with different providers ( T-online, MSN, and my own ppp Server) on 486er and Pentium machines using the AVM Fritz and an Elsa Microlink card.

Specific questions conserning the Hisax driver can be looked up at the i4l faq and the Readme for Hisax

Special cases like canal bundeling, callback etc are not yet tested but should be possible. Refer to the hisax guide. Although the use of active cards, like the avm b1, is possible,it is not tested, and should require some extra work.

Users with external ISDN modems should look at the ppp dial up page..

Comments on this section should be addressed to its maintainer: Eric Wolzak .


ISDN-cards connect quiet, and usually without any signs. If you have a wrongly configured machine on your network, you could experience a lot of undesired connections: you will not notice it until the next telephone bill!. So, especially for a start, check your messages file regulary. I use the beep.lrp which gives an audible signal on connecting. During the setup disconnect the ISDNline until you know that all other parts do function.

Step 1: Download and declare the isdn.lrp package

Download the isdn.lrp package from Eric's site and store it on your Bering disquette. If you need space to do that, refer to the installation guide to learn how to do that.

Boot your Bering floppy image. Once the LEAF menu appears get access to the linux shell by (q)uitting the menu. Edit the syslinux.cfg file and REPLACE the pump entry by isdn in the LRP= list of packages to be loaded at boot. Check the Bering installation guide to learn how to do that.

Your syslinux.cfg file will then look like (adjust to your tastes):

display syslinux.dpy
timeout 0
default linux initrd=initrd.lrp init=/linuxrc rw root=/dev/ram0 boot=/dev/fd0u1680:msdos
	PKGPATH=/dev/fd0u1680 LRP=root,etc,local,modules,iptables,keyboard,isdn,shorwall,ulogd,dnscache,weblet


The last two lines ("default linux ... dnscache,weblet") must be typed as a single one in syslinux.cfg

Step 2: download the isdn.o and the appropriate hisax.o modules

It's now time to download ISDN modules. You need both the isdn.o module and the hisax.o modules.

You can use the "normal" hisax.o module, with built-in support for every cards. But this module has a size of about 600K, so you will have a problem getting everything on a single disk. This is why I compiled "partial" hisax modules, each supporting a small group of cards. It will be a little be more work to select the correct one if you have an exotic card, but the size of less than 250 K will be worth the trouble. To see what Hisax module you need check the following table

Table 9.1. Available ISDN modules

Teles_16_0Teles S0-16.01irq, mem, io
Teles_16_0Teles S-8 en compatibele2irq, mem
Teles_16_3Teles S0-16.33irq, io
Teles_16_3 Teles/Creatix PNP4irq, io0 (ISAC), io1 (HSCX)
Teles PCMCIA Teles_PCMCIA8irq, io
TelesPCI Teles PCi21no parameter
S0_BoxTeles/Creatix parallel port S0Box25irq, io (of the used lpt port)
hisax_AVM_A1AVM A1 ( Fritz)5irq, io
hisax_AVM_A1Teledat 1505irq,io
hisax_FRITZ_PCI AVM Fritz!PnP27irq, io (from isapnp setup)
hisax_FRITZ_PCIAVM Fritz!PCI27no parameter
hisax_AVM_A1_PCMCIAAVM A1 "Fritz!PCMCIA"26irq, io (set with card manager)
hisax_ELSAElsa Microlink ISA6io or nothing for autodetect (the iobase is required only if you have more than one ELSA card in your PC)
hisax_ELSA Elsa Quickstep series isa7irq, io (from isapnp setup)
hisax_ELSAElsa Quickstep 1000 pci18none
hisax_ELSAElsa Quickstep 3000 pci18none
hisax_ELSA Elsa PCMCIA10irq, io (set with card manager)
hisax_IX1MICROR2 ITK ix1-micro Revision 2 card9irq, io
hisax_DIEHLDIVA Eicon Diehl Diva none Pro version11irq, io
hisax_ASUSCOMAsusCom ISA (isdnlink)12irq, io (from isapnp setup)
hisax_ASUSCOMDynalink IS64PH (oem)12irq, io (from isapnp setup)
hisax_ASUSCOMPCBit-DP (oem)12irq, io (from isapnp setup)
hisax_TELEINT TELEINT SA1 semiactiv13irq,io
hisax_HFCS HFC-S 2BDS0 based cards13irq, io
hisax_HFCS teles 16.3c pnp14irq, io
hisax_SEDLBAUERSedlbauer Speed Card15irq, io
hisax_SEDLBAUERSedlbauer PC/10415irq,io
hisax_SEDLBAUERSedlbbauer pci15none
?Acer30irq, io (from isapnp setup)
hisax_SPORTSTERStollmann tina-pp V316irq,io
hisax_SPORTSTER USR Sportster internal TA16irq, io
hisax_MIC ITH MIC Card17irq, io
hisax_NETJETOvislink ISDN sc100-p card20none
hisax_NETJET Traverse Technologies Netjet20none
hisax_NETJET_U Traverse Technologies Netspider U38none
hisax_NICCY Dr. Neuhaus Niccy PNP24irq, io0, io1 (from isapnp setup)
hisax_NICCYDr. Neuhaus Niccy PCI24no parameter
hisax_ISURFSiemens I_Talk (IsAR chip)29 ?irq, io, memory (from isapnp setup)
hisax_ISURF Siemens I-Surf (ISAR chip) 1.029irq, io, memory (from isapnp setup)
hisax_ASUSCOM Siemens I-Surf (IPAC chip) 2.012irq, io (from isapnp setup)
hisax_HSTSAPHIR HST Saphir card31irq, io
hisax_BKM_A4TBerkom Telekom A4T Card32none
hisax_SCT_QUADRO Scitel Quadro card33subcontroller (4*S0, subctrl 1...4)
hisax_GAZEL Gazel card isa34irq,io
hisax_GAZELGazel card pci34none
hisax_HFC_PCI HFC-S PCI 2BDS035none
hisax_W6692 Winbond W6692 based PCI cards36none
hisax_HFC_SX HFC-S+37irq, io
hisax_HFC_SXHFC-SP37irq, io
hisax_HFC_SX HFC-SP/PCMCIA39irq,io (set with cardmgr)

Once you have downloaded the appropriate module rename it to hisax.o and copy it to the /lib/modules directory.

Step 3: declare the ISDN modules

In order to have an ISDN connection working, you need to have ISDN support enabled through the appropriate kernel modules. You also need to declare the driver(s) module(s) of your internal network card(s). In the following example, we assume that your internal network card is a NE2000 PCI.

To declare your modules, go to the LEAF Packages configuration menu and choose modules. Enter 1) to edit the /etc/modules file and enter the following information:

# 8390 based ethernet cards

# Modules needed for ISDN
# Look for type, io and irq settings at help page of isdn.lrp documentation
hisax type=   io= irq=

# Masquerading 'helper' modules

the paramater you have to give for a certain card are listed in the table above

as an example: to use Fritz card from AVM(A1) download the module hisax_AVM_A1. rename it to hisax.o. if you fritzcard is configured with irq 7 and ioport 330 you enter hisax type=5 irq=7 io=0x330

Backup the modules.lrp package.

Step 4: configure ISDN

Most options are already defined with reasonable default values. But some settings must be defined in every case. If you have a static ip number you should also change the according parameter.

Through the LEAF Package configuration menu choose isdn. The following menu will appear:

                       isdn configuration files

        1) ipppd options
        2) password und userid
        3) ipppd scipts to startup the ipppd interfaces

select 1 now you edit the User setting and enter here the name or number that you need to identify yourself

#  USER Dependent options
# your MSN depending on your country without areaprefix
# Provider MSN
# Hangup after idletime in seconds 0 for no hangup

What your MSN is, is depending on the country you live in.If you are in doubt, ask your local telco.For a few countries you can find the answer here. The remote MSN (REMMSN) is the nummer you have to dial from the connection the router is attached to, including extra digits exactly as you would dial it.

You might want to change the time set to keep the line up if there is no activity. As a default it is set to 60 (sec),which is relatively short. You change this with the parameter TIMEOUT

now use the password and userid from the isdn configuration menu set your login name (eric@foobar).I can login with this name on any computer (*). I have to identify me with the password ("this_is_a_secret")

# This is a pap-secrets file
#papname * papsecret *  "this_is_a_secret"


If you have ppp installed, the pap-secrets file is shared and this could give problems with the backup. You don't need ppp for isdn.lrp

backup the isdn package

Step 5: configure your interfaces file

Through the LEAF configuration menu type 1 to access to the network configuration menu and 1 again to edit your /etc/network/interfaces file. Enter the following information:

auto lo eth0

iface lo inet loopback

iface eth0 inet static
	masklen 24


attention the internal interface is now eth0 assuming you have only one interface!

your external interface is now ippp0, but this interface is not setup in the interfaces file

Step 6: configure Shorewall

Through the LEAF packages configuration menu, choose shorwall and check the two following files:

A/ The interfaces file (entry 3) defines your interfaces. Here connection to the net goes through ippp0 and the connection to the internal network through eth0. So we must set:

net     ippp0           -	        dhcp,routefilter,norfc1918
loc     eth0            detect          routestopped


Do not forget the "-" under the BROADCAST heading for the net/ippp0 entry.

B/ The masq file (entry 7). In this type of setting it should look like:

#INTERFACE              SUBNET
ippp0                   eth0

Backup the shorwall.lrp package.