The T-SERV II CSU offers local management of T1 service lines. It meets all FCC and carrier requirements for a standard interface between the user and the network. The T-SERV II is NRTL listed to UL1950. All basic CSU functions are contained in the T-SERV II CSU, including bipolar violation (BPV) correction, line build-out, loop-code generator for fault isolation, front-panel LED status indicators, test jacks, power options and automatic keep-alive signal generation. Its transparent operation passes the T1 bitstream unaltered.