Patent ID: 8265230

Claim:
Apparatus for patching into a communications trunk such that the apparatus has an east end coupled to echo cancellers for subscriber terminals and the apparatus has a west end coupled to the communications trunk, wherein the communications trunk includes a transmit DS-1 line and a receive DS-1 line each carrying multiplexed DS-0 signals, and wherein said apparatus is connected in series by a jumper connection into the communications trunk such that the transmit DS-1 line has respective east and west ends and the receive DS-1 line has respective east and west ends, comprising: a first line interface for providing layer-1 interfacing to said east end of said transmit DS-1 line and said east end of said receive DS-1 line; a first framer coupled to said first line interface providing layer-2 interfacing to make available frames of multiplexed individual subscriber DS-0 signals from said transmit and receive DS-1 lines; and a test controller coupled to said first framer for continuously de-multiplexing said frames from said first framer corresponding to said transmit DS-1 line, sampling a de-multiplexed individual transmit signal from a selected individual subscriber DS-0 signal, storing said samples in a queue for a selected echo delay, adding said samples to an individual receive signal for said selected individual subscriber DS-0 signal after said selected echo delay, continuously re-multiplexing said frames, and providing said re-multiplexed frames to said first framer for returning to said east end of said receive DS-1 line.