Patent ID: 7072361

Claim:
In a digital wrapper format network, a method for transporting backward information, the method comprising: receiving downstream messages with payload and overhead bytes as follows: receiving messages in a frame format with an overhead section; dropping the overhead section; selectively reading backward message monitor bytes in the dropped overhead section; and, determining if an upstream communications node is receiving transmitted messages; selectively replacing overhead bytes with calculated overhead bytes as follows: determining errors in the downstream messages expressing the errors in the form of transmit overhead bytes; and, selectively overwriting at least one backward overhead byte in the backward message monitor bytes of the overhead section with transmit monitor overhead bytes; and, supplying the calculated overhead bytes for upstream messages as follows: writing a buffer with the transmit monitor overhead bytes using write timing signals responsive to the downstream messages; and, reading the transmit overhead bytes into an upstream message from the buffer using read timing signals responsive to the upstream messages; wherein writing a buffer with the transmit monitor overhead bytes using write timing signals responsive to the downstream messages includes writing a first set of transmit monitor overhead bytes from a first received frame, and overwriting the first set of transmit overhead bytes with a second set of transmit overhead bytes from a second frame following the first frame; and, wherein reading the transmit overhead bytes into an upstream message from the buffer using read timing signals responsive to the upstream messages includes reading the first set of transmit overhead bytes into a first transmit frame before they are overwritten by the second set of transmit overhead bytes.