isdnexam 1.01.0 README

David Cutting (

You have downloaded and extracted isdnexam 1.01.0, for use with the isdn4linux tools to allow automation of state reading and/or line control.

The package comes with the pre-compiled binaries (gcc under RedHat Linux 6.2) as well as the source code. The binaries and source are contained in the code directory and the binaries will be overwritten if you recompile the source yourself.

If you wish to recompile (if for example the binaries are not working under your system) do:


If you are happy to go ahead and install (or wish to install your new binaries) do (as root):


This creates the /isdn directory and it's subsequent directory structure and installs the isdnexam script in /usr/local/sbin.

Assuming the kernel module for ISDN is loaded (so isdnctrl works) then you can now run isdnexam.

isdnexam provides four command line options:

exam : examines the linestate and displays states for both the 64kbps and 128kbps lines.

auto : examines the linestate and dials if it can (eg 64k down or 64k up and 128k down)

help : help on these commands

version : display version number

It is IMPORTANT to note that the /isdn/isdnres file will need to be edited for your configuration. I included the complete subsystem restart owing to kernel crashes under RedHat 6.1 and 6.2 when the line is remotely dropped and reconnected and the first packet is sent. On a fast system this will take barely any time. If you are happy with your setup and are not experiencing this then you can null the /isdn/isdnres file (though it MUST exist and be executable). Change your number and/or protocols in the file and away you go.

Please now read the enclosed documentation in the doc directory!!

David Cutting, August 2000.