When configuring the Ethernet Layer 2 attribute, set the Default VLAN ID and VLAN Priority of the untagged frame when the TAG ID is set to Accese or Hybrid. The "VLAN priority" is set according to the QoS of the unified plan.

The ROADM site using WSMD9 board can support up to 9 dimensions. If it exceeds 9 dimensions, it can be implemented by cascading WSMD9 boards.

The wave division system complement to chromatic dispersion mainly adopts the DCM compensation method. The following statements about DCM dispersion compensation, which is wrong?

Which of the following alarms will trigger the optical line protection switching? (Multiple choice)

In the Colored&Directioned scenario of the 4D ROADM, if you want to implement local service scheduling in four directions, how many sets of M40V+D40 are needed?