DCT3-GSMTAP is a command line utility to capture the GSM Um and SIM-ME interfaces from a Nokia DCT3 phone (eg. 3310) and forward via GSMTAP to the Wireshark protocol analyzer. It is released under GNU GPL version 2.
It is heavily based on Gammu http://www.gammu.org and Project Blacksphere http://nokix.pasjagsm.pl/help/blacksphere/sub_200nokiaos.htm which is the result of a great deal of assembly code reading, research, countless (mostly futile) searches for data sheets, cross-referencing and analysing by wumpus firstname.lastname@example.org (and others in the credits section).
A serial/USB FBUS cable is required - these should be readily available, normally used for ringtones etc, try searching for "3310 data cable". Images from https://svn.berlin.ccc.de/projects/airprobe/wiki/tracelog
dct3-gsmtap device host
The device should be something like /dev/ttyUSB0 (check dmesg once plugged in for exact name) or /dev/ttyS0. The host is where to send the GSMTAP packets to (126.96.36.199 is a good option). If you then run wireshark on the relevant interface, you'll see GSMTAP messages.
Duncan Salerno email@example.com - please let me know if you have success with non-3310 phones and I'll add them to the wiki!
The source code is kept in the git repository at git://git.osmocom.org/dct3-gsmtap.git, which you can browse
best from http://cgit.osmocom.org/