SDH Transport Overhead
SDH provides substantial overhead information, allowing simpler multiplexing and greatly expanded OAM&P capabilities. The SDH transport overhead, as illustrated in Figure 6-7, has two layers that include the RSOH and MSOH. The RSOH is used for communications between adjacent NEs, such as regenerators, whereas the multiplex section overhead is used for the STM-N signaling between STM-N multiplexers. The reader must make a genuine attempt to comprehend this section because a large part of understanding SDH includes understanding the purpose and use of the overhead bytes.
Figure 6-7. SDH Transport Overhead
SDH Regenerator Section Overhead
The RSOH contains only the information required by the NEs located ...