The Care and Feeding of ISDN4BSD
7.2 Analyzing an S0	The Care and Feeding	8.1 Setting the debug

8 The isdndebug Utility

Isdndebug is used for several purposes, it got its name from the fact that most of the time it is used to set the debug level for the four layers of isdn4bsd inside the kernel.

In general, this utility is only of use if you debug i4b's kernel part or are writing or debugging i4b hardware drivers.