Dear friend!
Link degradation is usually caused by the deterioration of the quality of the optical wavelength channel where the service is located or the board or optical module is faulty.
Fault location:
Check whether other services with the same source and sink have the same alarms and performance deterioration.
1. If this problem occurs on services on all channels, rectify the link fault on the working optical channel.
2. If this problem occurs only for single-wavelength services, rectify the fault between the multiplexer/demultiplexer board and the line board.
3. If only this ODU4 board is faulty but other services in the same wavelength as other services do not have this fault, rectify the fault of the tributary board.
Troubleshooting:
1. Check whether the input optical power of the board is within the normal range. If the optical power is not within the normal range, see the handing procedure of the IN_PWR_HIGH and IN_PWR_LOW alarms for troubleshooting.
2. If the alarm persists, check whether the pigtail meets the following requirements:
The bending radius is not less than 6 cm.
The fiber connectors are properly installed.
The fiber connectors are clean.
The cable is intact.
If the preceding requirements are not met, clean the fiber connector or replace the pigtail.
3. Check whether the amplifier configuration is proper.
4. Check whether the OSNR threshold is set properly.
5. If any problem exists, replace it with the same optical module and board. check whether the hardware is faulty. If yes, replace it forever.
Thank you！
