Old ISDN4Linux (obsolete)

modulename: isdn.ko

configname: CONFIG_ISDN_I4L

Linux Kernel Configuration
└─>Device Drivers
└─>ISDN subsystem
└─>Old ISDN4Linux
└─>Old ISDN4Linux (obsolete)
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
This driver allows you to use an ISDN-card for networking
connections and as dialin/out device. The isdn-tty's have a built
in AT-compatible modem emulator. Network devices support autodial,
channel-bundling, callback and caller-authentication without having
a daemon running. A reduced T.70 protocol is supported with tty's
suitable for German BTX. On D-Channel, the protocols EDSS1
(Euro-ISDN) and 1TR6 (German style) are supported. See
Documentation/isdn/README for more information.

ISDN support in the linux kernel is moving towards a new API,
called CAPI (Common ISDN Application Programming Interface).
Therefore the old ISDN4Linux layer is becoming obsolete. It is
still usable, though, if you select this option.

source code: