When different routes are used for client-side 1 + 1 protection, the working wavelength and protection wavelength cannot use the same wavelength.

Which of the following statements about the electrical-layer overhead processing - source function are correct?

After starting the extended SSM protocol, in addition to determining the clock quality level and priority, the clock ID is also determined. After receiving the clock signal with the ID, the network element considers that the source is unavailable if it is judged to be the clock signal sent by the station. In this way, even after passing through multiple sites, the network element can still recognize the clock signal sent by itself, preventing the formation of a timing loop.

As with the STP device, the NG WDM device can practice the network element configuration on the network through pre-configured method.

What are the classification of Ethernet performance tests? (Multiple choice)