osmo-e1-recorder is a program to record traffic on E1 or T1 TDM interfaces to disk. This provides tcpdump-like functionality for TDM interfaces.
You can configure on a per-timeslot base if the raw bitstream should be recorded, or if a HDLC decoder should be used.
Requires a high-impedance tap and two E1/T1 ports per link you want to monitor (one for Rx, one for Tx).
Commercial support as well as development, system integration and training services for this project are available from sysmocom