CONFIG_ISDN_CAPI (not configurable)

modulename: kernelcapi.ko

configname: CONFIG_ISDN_CAPI

Linux Kernel Configuration
└─>Device Drivers
└─>ISDN support
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
This provides CAPI (the Common ISDN Application Programming
Interface) Version 2.0, a standard making it easy for programs to
access ISDN hardware in a device independent way. (For details see
<>.) CAPI supports making and accepting voice
and data connections, controlling call options and protocols,
as well as ISDN supplementary services like call forwarding or
three-party conferences (if supported by the specific hardware

This subsystem requires a hardware specific driver.
See CONFIG_BT_CMTP for the last remaining regular driver
in the kernel that uses the CAPI subsystem.