The OTU3_LOF is an alarm indicating that the frame alignment signal(FAS) is abnormal. This alarm occurs when the frame alignment processing is out of frame (OOF) in three consecutive milliseconds.
- The signals transmitted by the corresponding board at the opposite end do not have a frame structure.
- The input optical power is abnormal.
- The FEC type is incorrectly configured.
- The fiber of the transmission line is abnormal