Transmission apparatus

A transmission apparatus for receiving a plurality of encoded user signals and for multiplexing the plurality of encoded user signals to thereby convert these signals into a single multiplexed signal, said apparatus comprising:

• a multiplexer performing multiplexing without altering contents including codes of the plurality of encoded user signals, and for sending the resulting multiplexed signal to a transmission path;
• a receiver receiving a multiplexed signal from another transmission apparatus via such multiplexed signal's associated transmission path and for separating the multiplexed signal into a plurality of encoded user signals without changing code contents of the multiplexed signal;
• and
• a synchronization processor performing synchronization processing with a block, which consists only of contiguous and adjacent ordered sets /C/, running disparity value is kept noninverted at an start and an end, by insertion or deletion of said block with respect to said code in detecting that an auto-negotiation ordered set is included in the plurality of encoded user signals and that the auto-negotiation ordered set has a data pattern whose running disparity value is kept noninverted at an start and an end, wherein said code is an 8B/10B code and /C/ is defined by the 8B/10B code, and wherein the received signal is an Ethernet signal.