The Protocol Tester K1103 has been developed for network supervision and network analysis of CCS#7, GSM, CDMA, ISDN D-channel, X.25 and V5.x protocols. A maximum of four different PCM links (T1/S2M) or V./X. links with up to eight signaling links (64 kbit/s, 56 kbit/s, 16 kbit/s) can be supervised simultaneously. More details here - unfortunately the service manual isn't public and I'm not allowed to upload it somewhere.
Indirect access to 4 of this machines can be given trough Holger.
Pinout of the E-1 interface
Monitor A: Pin Purpose 9 RX+B 5 RX-B 6 RX+A 1 RX-A 2,3,4 GND A = E-1-Linecard -> BTS B = BTS -> E-1-Linecard Monitor C: Pin Purpose 9 RX+D 5 RX-D 6 RX+C 1 RX-C 2,3,4 GND
Telephone socket: Pin Purpose 1 mic input (-) 2 hearer output (+) 3 hearer output (-) 4 mic input (+)