tfo-ut: check in tfo-fr.bin and tfo-efr.bin Each of these binary files is an extract from MSC-side E1 timeslot recording in a Nokia TCSM2 TFO session involving a cross-connect between two TRAU channels. The extracts have been chosen to begin at the point where the TRAU starts emitting TFO frames, thereby beginning with a series of TFO frames that contain an embedded TFO_TRANS message. In each experiment, one of the two cross-connected TRAU channels emitted two "plain" TFO frames (not containing embedded TFO messages) in between the initial embedded TFO_TRANS and the subsequent embedded TFO_REQ_L; this channel was chosen for the present extracts. Each extract is thus 2560 PCM samples, containing 16 aligned TFO frames: 5 carrying TFO_TRANS, 2 plain, 9 carrying TFO_REQ_L.

This repository contains tools and notes related to reverse engineering of
various components on the network side of GSM, as well as behavioral reverse
engineering of actual commercial GSM networks.