Hello, everyone.
This time, I'd like to share with you the process of handling bit errors on the WDM network. I'm sure it will help you.
If bit errors occur on the WDM network, please check the alarm and performance event through the network management to determine whether it is a multi-wave or single-wave bit errors.
If bit errors are generated on multiple wavelengths
1. Check whether the tail optical fiber or optical cable of the multiplexed wavelength is faulty.
a. Check the tail optical fiber of the multiplexing part. If it's abnormal, replace it.
The tail optical fibers of the multiplexing part include the tail optical fibers between the equipment and the ODF, the tail optical fibers between the OA board and the FIU board, the tail optical fibers between the OA board and the multiplexing board and the demultiplexing board, the tail optical fibers between the ODF, and the TDC and RD of the OAU. tail optical fiber between C.
b. Rectify the optical cable fault.
2. Check whether the device temperature is too high.
Check whether alarms such as TEMP_OVER are generated on the NE. If yes, check the equipment room environment and clean the dust filter.
3. Check whether the DCM module configuration is proper.
Check the optical cable parameters such as the optical cable type and actual length, check the DCM module configuration, and increase or decrease the DCM.
4. Check whether the optical power of multiplexed signals is normal.
Check the input and output optical power of all the boards that pass between the transmit-end multiplexer board and the receive-end demultiplexer board. If the input optical power is normal but the output optical power does not reach the standard output optical power, replace the board.
5. Check whether the flange between the device and the ODF is damaged.
Check the flange between the ODF and the WDM equipment. If the flange is faulty, replace it with a new one.
6. Check whether the PMD exceeds the threshold.
a. Test the fiber PMD of all spans and determine the PMD values of all spans. At the same time, splice the fiber splicing point with excessive PMD and splice the fiber splicing point with large attenuation. After the rectification, the attenuation characteristics of the fiber are improved.
b. If the PMD values of several spans exceed the recommended values, replace optical fiber to ensure long-term stable operation of the system and solve the system stability problems caused by the PMD.
7. Check whether the system has non-linear effects.
a. Increase or decrease the incident optical power and check whether bit errors are caused by system nonlinearities. In the following cases, it can be determined that bit errors are caused by system nonlinearity.
Increase the incident optical power. The bit error increases with the increase of the optical power.
Reduce the incident optical power. The bit errors decrease with the decrease of the optical power.
b. Increase the attenuation value of the variable attenuator or add a fixed attenuator to reduce the incident optical power to reduce bit errors.
If bit errors are generated on a single wavelength
1. Check whether the input optical power of the board is normal.
Check the input optical power of the OTU or tributary and line boards. If the input optical power is too low, please clean the tail optical fiber and reconnect it.
2. Check whether the tail optical fiber loss of the board is too large.
Check whether the tail optical fibers between the demultiplexer/multiplexer board and the OTU board, tributary/line board, MUX board, and the ODF are aged or bent, which may cause excessive loss. If yes, replace the tail optical fiber.
3. Check whether the device temperature is normal.
Check whether the TEMP_OVER alarm is generated on the NE. If yes, the operating temperature of the board is abnormal. Check the equipment room environment and clean the dust filter.
4. Check whether the FEC modes of the interconnected boards are consistent.
On the NMS, query the FEC modes of the two interconnected OTU boards or tributary and line boards and set the FEC modes to FEC or AFEC to ensure that the modes match.
5. Check whether the optical port on the board is clean.
If the optical ports on the OTU or tributary and line boards are not clean, use dedicated compressed air to spray the optical ports on the boards to clean the optical ports.
6. Check whether the board is faulty.
a. If the tail optical fiber, input power, and operating temperature are normal and the FEC mode of the board matches, replace the OTU or tributary and line boards at the receiving end. If bit errors disappear, the OTU or tributary and line boards at the receiving end are faulty.
b. If the OTU or tributary and line boards at the receiving end are normal, replace the OTU or tributary and line boards at the transmit end. If the bit errors disappear, the OTU or tributary and line boards at the transmit end are faulty.
If the fault persists, collect device alarms and performance check logs and contact Huawei engineers in the local office.
Extended Information
The causes of bit error in the transmission network
How to handle the Bit Error in MSTP network
That's all, I welcome everyone to leave a message and exchange in the comment area!
Thank you！
