isdn4linux is a set of kernel modules which are part of the Linux
kernel. It consists of the main module isdn and the
actual hardware driver that control some specific card.
In addition, the package isdn4k-utils contains utilities to
make use of ISDN specific features.
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 not make use of any devices connected via a serial or parallel interface (which are called 'terminal adaptors'). For more details on which cards are supported see section hardware.
Basically, isdn4linux can receive and transmit data via ISDN in many ways
(X.75, HDLC, raw ip, synchronous ppp, asynchronous ppp, V.110). Some of its
utilities offer additional features. Two examples are isdnlog, which
allows to log and react upon ISDN events (including calculating any charges);
and vbox which provides voice answering machine capabilities. For more
details see the section
feature.
At least all countries which use Euro-ISDN are supported, however some pecularities apply. To find more about your country, check section countries.
Besides this FAQ have a look at the various man pages and Readme's that come with the isdn4linux package. Then there is the isdn4linux website: http://www.isdn4linux.de. And there is also a news group and 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 docu.
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 distrib.
You can contact the isdn4linux developers through the www.isdn4linux.de website. Have a look at http://www.isdn4linux.de/contacts.