Method and apparatus for adapting, at a sink node, a constant bit rate client signal into the path layer of a telecom signal

A method comprising:

• receiving at a sink node a path signal frame and a modified set of idle character 64B/66B blocks at a respective link bit rate from a link segment, the path signal frame including encoded client data signal 64B/66B blocks, a plurality of path overhead 64B/66B data blocks and a control 64B/66B block;
• measuring the respective link bit rate using a sink node reference clock;
• determining the number of idle character 64B/66B blocks in the modified set of idle character 64B/66B blocks;
• extracting a count of data blocks that are to be sent from the plurality of path overhead 64B/66B data blocks;
• extracting the data blocks of a constant bit rate (CBR) client signal from the encoded client data signal 64B/66B blocks in the path signal frame;
• regenerating the CBR client signal from the extracted data blocks;
• determining a bit rate of the CBR client signal using the count of data blocks that are to be sent, the measured respective link bit rate and the number of idle character 64B/66B blocks in the modified set of idle character 64B/66B blocks;
• and
• adjusting the rate of a CBR client signal clock for transmitting the CBR client signal at the determined bit rate of the CBR client signal.

A sink node comprising:

• a digital signal processing (DSP) engine;
• a clock rate measuring circuit coupled to the DSP engine, the clock rate measuring circuit to use clock rate data from a 64B/66B client signal stream to measure a respective link bit rate;
• a GMP overhead and count idle extraction circuit to read a GMP window frame, to extract 64B/66B path overhead blocks and to count 64B/66B idle character blocks;
• a client payload extracting circuit to read data from the GMP window frame and to extract a constant bit rate client signal from the GMP window frame using a bit rate of the constant bit rate client signal determined using the count of 64B/66B idle character blocks and the measured respective link bit rate;
• and
• a FIFO buffer coupled to the client payload extracting circuit to receive the extracted constant bit rate client signal extracted from the GMP window frame and to output the constant bit rate client signal extracted from the GMP window frame.