Uri,
I believe Digital Path Transmission Functions Quality Supervision should accept your requirements.
This supervision being activated per DIP, so it can be used for A-bis or for A-ter or for A-if devices.
Commands:
DTQSC: Digital Path Transmission Functions Quality Supervision, Change 4/190 82-CNT 212 2132 Uen B
DTQSE: Digital Path Transmission Functions Quality Supervision, End 5/190 82-CNT 212 2132 Uen A
DTQSI: Digital Path Transmission Functions Quality Supervision, Initiate 6/190 82-CNT 212 2132 Uen A
DTQSP: Digital Path Transmission Functions Quality Supervision, Print 7/190 82-CNT 212 1988 Uen A1
DTQSR: Digital Path Transmission Functions Quality Supervision, Reset 8/190 82-CNT 212 2566 Uen A