The function of the pointer is to locate and indicate the starting position of VC-n in the corresponding AU or TU frame. Through positioning, the receiving end can correctly separate the…

The function of the pointer is to locate and indicate the starting position of VC-n in the corresponding AU or TU frame. Through positioning, the receiving end can correctly separate the corresponding VC from STM-N, and then separate the low-speed signals such as PDH by removing the encapsulation of VC and C, that is, to realize the function of directly dropping low- speed tributary signals from STM-M signals.