The alarm detection of the optical layer overhead is realized through the optical layer overhead OOS. Although the alarms such as R_LOS and MUT_Los are also optical layer alarms, they are not based on OOS detection and reporting, but based on optical power detection and reporting.

When the cross-connect board is configured with 1+1 hot backup, under normal switching conditions, the replacement of the cross-connect clock board will not affect the packet service.

The loss of optical fiber mainly includes which of the following options? (Multiple choice)

Which of the following descriptions about Flexible Grid is correct? (Multiple choice)

Which of the following unified line boards can support the crossover of VC, packet and ODUk at the same time?