9.
For the two fibers belonging to the repaired span, identify the fiber for the east to west (E–W) line
direction.
10.
Repeat the procedure from Step 5 to Step 8 for the E–W direction.
11.
If the LOS alarm has cleared, the system has restarted properly. However, because a significantly
different span loss value is now present, we highly recommended that you complete the following steps:
12.
Go back to the card where the LOS alarm is active, and set the optic thresholds (see Step 8b) to the
lowest value allowed.
13.
If the LOS alarm is has cleared, the system has restarted properly, but because a Span Loss value
significantly different from the design is now present, we highly recommend that you repeat the steps
described in Step 11.
DETAILED STEPS
Step 1
Verify the validity of the alarm.
Step 2
For both DWDM nodes connected to the repaired span:
a) Double-click the card directly connected with the span (either the OPT-BST, OPT-AMP-C, OPT-AMP-17-C, or
OSC-CSM).
b) Click
Alarms.
c) Click the
Synchronize
button on the bottom left of the window.
d) Verify that a LOS condition is present on the LINE-RX port.
e) If the alarm is correctly reported, move to Step 3. If not, close the CTC application, delete the CTC cache, and open
the CTC connection again. Then, go back to Step 1.
If the "gray condition" of the span persists, log into Technical Support Website at
for more information or call Cisco TAC ( 1 800 553-2447) in order to report a service-affecting
problem.
Step 3
Measure the new Span Loss value after fixing the fiber.
a) In the node view (single-shelf mode) or shelf view (multishelf mode) of both nodes for the span, click the
Maintenance > DWDM > WDM Span Check
tabs.
b) Click
Retrieve Span Loss Values
to retrieve the latest loss data.
The two values retrieved at each node level (west side and east side) refer to the two fibers coming into
the node from the adjacent nodes, so they apply to different spans. To complete the measurement in Step
3, the appropriate values must be taken into account.
Note
Step 4
Compare the span measurements of Step 3 with the span losses values used during the network design with Cisco
TransportPlanner.
Step 5
For the two fibers belonging to the repaired span, identify the fiber for the W–E line direction and calculate the insertion
loss variation. If the span loss change is greater than 3 dBm, continue with Step 6. If not, go to Step 9.
Step 6
Clean the LINE-RX and LINE-TX connectors on the DWDM cards managing the fiber of the repaired span. If the
problem persists, continue with Step 7.
Step 7
If the alarm condition is still reported, it is recommended that the fiber be repaired again to reestablish the expected
span loss value. If this is not possible and the new value of span loss cannot be modified, go to Step 8 to fix the system
faulty condition.
Cisco NCS 2000 series Troubleshooting Guide, Release 11.0
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General Troubleshooting
Corrective Action for Scenario 2
