APPARATUS FOR ADAPTING A CONSTANT BIT RATE CLIENT SIGNAL INTO THE PATH LAYER OF A TELECOM SIGNAL

A source node for rate adapting a constant bit rate client signal into a signal stream in a 64B/66B-block telecom signal communication link includes a GMP engine; a FIFO buffer coupled to receive a 64B/66B encoded client data stream; a clock rate measuring circuit; a source of 64B/66B path overhead blocks; a source of 64B/66B pad blocks; a source of 64B/66B idle blocks; a multiplexer; and a multiplexer controller. A control 64B/66B block is encoded into an ordered set block-designator and a count of data blocks to be sent in a next path signal frame is encoded into a plurality of path overhead 64B/66B data blocks. The multiplexer controller is responsive to a count of data blocks to be sent in a next path signal frame from a previous GMP window frame to selectively pass data to a data output so as to fill a GMP window frame.