Abstract: Circuitry for a node of an optical communication network is configured to mux (i.e., combine) one or more incoming customer signals for transmission as a single outgoing optical signal and to demux (i.e., split) an incoming optical signal into one or more outgoing customer signals, where the muxing and demuxing clocks are selected from one or more customer clocks recovered from the one or more customer signals, an input clock recovered from the incoming optical signal, and a local clock generated by a local clock generator. When configured for an add/drop configuration, the circuitry selects (1) the muxing clock from the one or more customer clocks, the input clock, and the local clock and (2) the demuxing clock from the input clock and the local clock. When configured for a drop/continue configuration, the circuitry is configured to select both the muxing and demuxing clocks from either the first input clock or the local clock.

Abstract: The integrity of AMA records generated by a switch in the telephone network is achieved by generating test calls and then monitoring and then processing the AMA records generated by those switches in the network which handled the test call. Such monitoring includes tracking for the AMA records that have been generated for the test calls and then processing those records such that the contents of the fields forming the records are analyzed to determine that the data contained therein is correct.