Hi
there, Community friends! This time, I will share with you about TCM. Hope
you
like it!
This topic describes the tandem connection monitoring (TCM) in terms of background, function definition, and benefits to networks.
When an STM-N frame is cross-connected at each station, each station processes B1 and B2 bytes. In this way, a failure point can be quickly located on a network.
The B3 byte evaluates the bit errors in a VC-4. Only when the VC-4 is used to add or drop services at a station, the station processes the B3 byte. When a VC-4 passes through several or dozens of stations before it adds or drops services, the intermediate stations only transparently transmit the B3 byte. Hence, when bit errors occur, it is hard to determine the failure point. If a VC-4 service passes through the networks of two or more carriers who may use different network management systems, a dispute occurs between the carriers.
The TCM technology is created to solve the preceding problems. On a large network, or when network resources are leased to different network carriers, the TCM is used to monitor the quality of transmission paths in a specific network area (for example, the transmission network of the line resource leaser). The TCM function that uses the N1 or N2 overhead byte does not require you to use the network management system to query all stations, but to query only the quality report of paths at the TCM sub-layer at the edge interface of the network. In this way, a fault is located or a network dispute is solved quickly.
That's all, I welcome everyone to leave a message and exchange in the comment area!
