RAU board reporting R_los alarm

liqiang185 · Created Jan 20, 2022 02:32:36

Dear friend!

The RAU board is an optical line amplifier board. If the R_LOS alarm is reported on the RAU board, the fault occurs on the WDM side.

Based on the signal flow diagram, check the optical links in the following two places:

RAU

1. Optical link between the LINE port on the RAU board and the OUT port on the peer FIU board.

2. Optical link between the IN port on the RAU board and the TC port on the local FIU board(In addition, the optical link between the TDC port on the RAU board and the RDC port is included.).

Possible causes and handling methods:

Cause 1: No fiber jumper is connected to the optical port on the board of the local station, the fiber jumper connected to the optical port is loose, or the fiber jumper is connected incorrectly.

1. Check the fiber jumper connection on the board that reports this alarm at the local station

2. Check whether this alarm is cleared. If the alarm persists, check whether the fiber jumper is connected properly. Reconnect fiber jumpers between boards according to the actual networking environment.

3. Check whether this alarm is cleared. If the alarm persists, see the alarm handling procedure for cause 2 of this alarm generated on the WDM side.

Cause 2: The line attenuation is excessively high or there is a fiber cut.

1. On the NMS, check whether the received optical power at the optical port is within the permitted range.

2. Check whether this alarm is cleared. If the alarm persists, see the alarm handling procedure for cause 3 of this alarm generated on the WDM side.

Cause 3: The laser of the board at the opposite station is shut down.

1. On the NMS, check whether the laser on the board at the opposite station is on. If not, open the laser.

2. Check whether this alarm is cleared. If the alarm persists, see the alarm handling procedure for cause 4 of this alarm generated on the WDM side.

Cause 4: The transmit module of the opposite station or receive module of the local station is faulty.

1. If the alarm persists, check whether the board at the opposite station or the board at the local station supports pluggable optical modules.

2 Check whether this alarm is cleared. If the alarm persists, contact Huawei for assistance.

More details: R_LOS (OTN)

Thank you!

faysalji · Created Jan 19, 2022 16:20:49

For IF boards, the R_LOS alarm indicates that microwave frames are lost on the receive line side.

For SDH line boards, the R_LOS alarm indicates that signals are lost on the receive line side.

For TDM cascading interface boards, the R_LOS alarm indicates that cascading signals are lost on the receive line side.

Impact on the System

If
no protection scheme is configured, services on the board that reports
the alarm are interrupted. If a protection scheme is configured, a
protection switchover is triggered.

Possible Causes

Cause 1: Other alarms trigger the R_LOS alarm (if the R_LOS alarm is reported by an IF board).
Cause 2: The line performance deteriorates (if the R_LOS alarm is reported by an SDH line board).
Cause 3: The TDM cascade cable connection is abnormal (if the R_LOS alarm is reported by a TDM cascading interface board).
Cause 4: The transmit unit of the peer NE is faulty.
Cause 5: The receive unit of the local NE is faulty.
Cause 6: No fiber jumper is connected to the optical port on the board that reports the R_LOS alarm.
Cause 7: The laser on the peer NE is closed.
Cause 8: A fiber cut occurs on the transmission line.
Cause 9. The optical loss is beyond the normal range.

Procedure

Cause 1: Other alarms trigger the R_LOS alarm (if the R_LOS alarm is reported by an IF board).
1. If the R_LOS alarm is reported by an IF board, check for and clear any MW_BER_EXC, MW_BER_SD, and MW_FEC_UNCOR alarms on the IF board. If no such alarm exists, go to the next step.
2. Set an inloop on the IF port that reports the R_LOS alarm.
3. If the R_LOS alarm persists, perform the operations required when the R_LOS alarm is reported due to the other causes.
Cause 2: The line performance deteriorates (if the R_LOS alarm is reported by an SDH line board).
1. If the R_LOS alarm is reported by an SDH line board, exchange the transmit and receive fiber jumpers at both ends.
2. If the peer line port reports an R_LOF alarm after fiber jumpers are exchanged, go to Cause 8.
3. If the R_LOS alarm persists, perform the operations required when the R_LOS alarm is reported due to the other causes.
Cause 3: The TDM cascade cable connection is abnormal (if the R_LOS alarm is reported by a TDM cascading interface board).
1. If
  the R_LOS alarm is reported by a TDM cascading interface board, check
  whether the TDM cascade cable is properly connected and functional. If
  the cable is not properly connected, connect it properly. If the cable
  is faulty, replace it.
2. If the R_LOS alarm persists, perform the operations required when the R_LOS alarm is reported due to the other causes.
Cause 4: The transmit unit of the peer NE is faulty.
1. Replace the board where the peer line unit is located or the peer IF board.
2. Replace the system control, switching, and timing board on the peer NE.
3. If the R_LOS alarm persists, perform the operations required when the R_LOS alarm is reported due to the other causes.
Cause 5: The receive unit of the local NE is faulty.
1. Replace the board that reports the R_LOS alarm.
2. If the R_LOS alarm persists, perform the operations required when the R_LOS alarm is reported due to the other causes.
Cause 6: No fiber jumper is connected to the optical port on the board that reports the R_LOS alarm.
1. Check fiber connections and ensure that fiber jumpers are properly connected.
2. If the R_LOS alarm persists, perform the operations required when the R_LOS alarm is reported due to the other causes.
Cause 7: The laser on the peer NE is closed.
1. Turn on the laser on the peer NE.
2. If the R_LOS alarm persists, perform the operations required when the R_LOS alarm is reported due to the other causes.
Cause 8: A fiber cut occurs on the transmission line.
1. Test the transmission line connectivity, identify the cause of fiber cuts, and re-connect or replace related optical fibers.
2. If the R_LOS alarm persists, perform the operations required when the R_LOS alarm is reported due to the other causes.
Cause 9. The optical loss is beyond the normal range.
1. Check
  whether there are any blocks in the microwave transmission path or in
  the near field of the antenna. If there are any blocks in the microwave
  transmission path or in the near field of the antenna, adjust the
  mounting height of the antenna to ensure good line of sight (LOS) or
  re-plan the microwave link route.
2. Verify that the optical power of the optical module at the transmit end matches that of the optical module at the receive end.
3. Check
  whether loss increases because the antenna, hybrid coupler, or flexible
  waveguide is damaged or wet. If loss increases because any of the
  preceding components are damaged or wet, replace the faulty components.
4. If the R_LOS alarm persists, contact Huawei technical support engineers to handle the alarm.

Related Information

The handling procedure also applies when the R_LOS alarm is reported by an STM-1e port.

Unicef · Created Jan 20, 2022 01:53:06

Hello friend! hope it can help:

Root Cause
1. The boards are faulty.
2. The fiber connections are incorrect.
Suggestions
1. The service alarm indicator (SRV) gives green light when the NS2 reports the OCH_SSF-O alarm or when the FIU board reports the OTS_LOS-O alarm. This means that the alarm is not generated at the board side.
2. The two alarms are related to the logical fiber connection from the FIU to the SC1. Neither alarm is reported if no logical fiber is created from the FIU to the SC1.
3. To handle the unfamiliar alarms, refer to the Alarms and Performance Events in the relevant product manual.

Thanks!

liqiang185 · Created Jan 20, 2022 02:32:36