tandem connection monitoring (TCM)

Tandem Connection Monitoring (TCM) is a technique for monitoring carrier sections in SDH networks.

Since an SDH network is often managed by different network operators, the quality of the individual sections must be monitored. This is done in the path overhead( POH) of the synchronous transfer mode( STM). The binding data set for monitoring, the N byte in the path overhead, has a length of 1 byte, of which the first four bits are used for parity checking on the section.