The pointer is used for alignment, indicating the starting position of the VC in the corresponding AU or TU. In this way, the corresponding VC can be correctly removed from the STMN, and then the VC…

The pointer is used for alignment, indicating the starting position of the VC in the corresponding AU or TU. In this way, the corresponding VC can be correctly removed from the STMN, and then the VC and C package are separated into separate low-rate signals, such as PDH. That is, the low-rate tributary signal can be directly discarded from the STMN signal.