net-dialup sbriesen@gentoo.org Stefan Briesenick isdndump is an analyzer for the ISDN D-channel data. It depends on the output of isdnlog, a tool of the isdn4linux package. isdndump decodes most of layer 2 and layer 3 messages on the D-channel. It was developed according to the ETSI (European Standard Telecommunication series) specification. So if in your country any country specific extensions of ISDN are existing, isdndump will be probably unable to fully decode the protocol.