DAHDI telephony interface - source code for kernel driver

 DAHDI (formly Zaptel) is an interface for telephony devices used by e.g.
 the Asterisk PBX software. The dahdi-* packages provide the kernel
 DAHDI kernel modules and their required setup environment, as well as
 basic headers for building DAHDI modules and utilities.
 .
 It is normally used to build kernel modules package: m-a a-i dahdi-source