A.E-Line service based on VL.AN

B.Point-to-point transparent transmission of E-Line services

C.E-Line carried by PW

D.E-Line service based on QinQ

A.The network element broadcasts the clock quality information and the clock source ID of the synchronization source through the downstream station between the S1 bytes, and notifies the upstream station that the clock quality from the local network element is "not available for synchronization" by the S1 byte in the direction of the synchronization source.

B.If there are multiple clock sources with the highest quality level, the network element selects the clock with the highest clock priority as the synchronization source.

C.According to the clock source priority table, the network element first selects the clock with the highest quality level from the available clock sources as the homologous source.

D.The network element broadcasts the clock quality information of the synchronization source to the downstream site through the S1 byte, and notifies the upstream station that the clock quality from the local network element is "not available for synchronization" by the S1 byte in the direction of the synchronization source.

A./For functional units that have backups, check whether the switchover is normal.

B.Check the indicator blinking status of the board and ensure that the board works properly.

C.Ensure that no abnormal alarm.

D.Record the settings of jumpers and DIP switches on the board.

A.WSIM9+WSD9

B.WSM9+RDU9

C.WSD9+RMU9

D.WSMD9

A.One board change, two loopbacks, three analysis.

B.One analysis, two loopbacks, three board change.

C.One loopbacks, two board change, three analysis.

D.One analysis, two board change, three loopbacks.