For a 10G OTU board, the receiving end optical module uses PIN module. Which of the following receiving powers is in the normal receiving range of the board?

In a typical chained NG WDM network (such as A -> B -> C, A, B, and C are three sites), it is found that the official telephone number between the stations is not available during the commissioning. What are the possible reasons? (Multiple choice)

A, C are the WDM OTM stations, and B is the relay station. When the transmission direction of the A to B stations is interrupted, the Wavelength side of the B-stack OTU relay board reports the R_LOS emergency alarm and runs the processing to the upstream A.
The station side OTU2_BDI secondary alarm. At the same time, the alarm continues to be transmitted to the downstream station of the B station. After the alarm is processed at the C site, the ODU2_PM_AIS minor alarm is reported on the WDM side of the C-site OTU, and the ODU2_PM_BDI secondary alarm is transmitted back to the upstream station A.

The single-fiber bidirectional WDM system uses only one fiber to transmit optical signals in both directions simultaneously. The optical signals in both directions should be arranged at different wavelengths.

During the configuration of the E-LAN, the "MAC Address Learning Mode" can be set to SVL and IVL. SVL is a stand-alone VLAN learning, and IVL is a shared VLAN learning.