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 following description of the Flexible ROADM, which is wrong?

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

The following description of the PM_BIP8 related alarm, which is correct?

MPLS APS is a network protection mechanism that implements service creation through the detection function of MPLS OAM.