Which of the following statements are correct about PTN alarms?()
B.Loss of connectivity of TMP maintenance node means the CV frame. sent by the peer MEP is not received within three and a half frame. periods.
C.The service layer signal being invalid of TMP maintenance node means a fault occurs in the upstream service layer, including LOC, MISMERGE, unexpected MEP and LCK, and the service layer inserts FDI message into the adjacent client layer. The client layer reports the SSF alarm after receiving the FDI message.
D.Unexpected CV packet period of TMC maintenance node means the MEG ID of the received CV frame. does not match the local MEG ID.