If the low-level crossover of SDH equipment is exhausted, there are several common optimization schemes (multiple choice)

A network is configured with 1+1 protection on the board. On a certain day, the working channel has a condition that triggers protection switching, but the service cannot be automatically switched to the protection channel, resulting in service interruption.
The cause of the failure may be: (multiple choice)

GR (Graceful Restart) is one of the key technologies to provide HA. GR can make the entire system uninterrupted in the event of a failure switch, and can realize rapid network convergence under normal conditions.

The IP address you use is 165.247.52.119, and the subnet mask is 255.255.240.0. Which subnet is your host?

Regarding the optical power commissioning of the RAU2 board, which of the following options is correct () (multiple choice)