It was tried to get the Fritz!Card DSL SL USB card to get going with a Novell/SuSE 9.1 with a custom Linux Kernel 2.6.7. It was hard...

First, read the following from the SuSE SDB(http://portal.suse.com/sdb/de/2004/04/DSL_SL.html) (in German). You do not need the mentioned RPM package if you have updated your installation via YOU recently. Make sure that every package which has the string "avm" or "capi" in its name is installed. Make sure that every CAPI option in the ISDN configuration of your kernel is somewhat activated. You have to install the drivers from AVM(ftp://ftp.avm.de/cardware/fritzcrd.dsl_sl_usb/linux/suse.91/fcdslslusb-suse9.1-3.11-04.tar.gz). The ISDN and the following DSL configuration via YAST should not be a problem. The LED called USB should be on. But alas, when trying to connect, this message was shown in the syslog:

capiplugin: CAPI_REGISTER failed CAPI not installed (0x1009) [No such device or address (6)]

Three things had to be done additionally to make it work.

1. SuSE seems to believe that /dev/capi20 should have major 192 and minor <I forgot>. This is wrong! It should be major 68, minor 0. Since SuSE replaces your custom /dev/capi20 with every boot you should recreate it in an init script.
   
   + copy a simple script like /etc/init.d/raw to /etc/init.d/devcapi
   + link from /etc/init.d/devcapi to /etc/init.d/rc5.d/S99devcapi
   + edit /etc/init.d/devcapi to do the following things in the start) section:

       rm /dev/capi20
       mknod /dev/capi20 c 68 0
       chown root.dialout /dev/capi20
       chmod 660 /dev/capi20
   

2. The installation process also fails to modify /etc/capi.conf, it should have a line like this in it:

     fcdslslusb fdlubase.frm - - - - -
   

   The firmware file should have already been put into /usr/lib/isdn/ by the installation scripts.
   Now the LED labelled DSL should start blinking, making a connection to the SLAM. Afterwards it should be lit steadyly. The CAPI_REGISTER message should disappear (it might be necessary to run capiinit start once), but a PPP connection is still not possible. The process writes a message with CONNECT <something I do not remember> into the syslog.
3. Run drdsl, it should print quite some stuff while setting up the modem. If it complains about some problems with CAPI, your configuration is still fucked up at some place.

From now on, these three steps are not necessary to be repeated. When connecting, the PPP LED starts blinking and stays lit when connected.