Cisco NCS 2000 series Troubleshooting Manual page 117

General Troubleshooting
Warning Invisible laser radiation could be emitted from the end of the unterminated fiber cable or connector.
Do not stare into the beam directly with optical instruments. Viewing the laser output with certain
optical instruments (for example, eye loupes, magnifiers, and microscopes) within a distance of 100
mm could pose an eye hazard. Statement 1056
Note Before disconnecting any optical amplifier card fiber for troubleshooting, ensure that the optical amplifier
card is unplugged.
Step 8 Follow the signal flow into the network starting from the repaired fiber:
a) In the downstream node, identify the OPT-BST, OPT-AMP-C, OPT-AMP-17-C, or OSC-CSM card that manages
OSC and CHS detection.
b) In card view, click the Provisioning > Optical Line > Optic Thresholds tabs.
c) Click the Alarms radio button, then click Refresh.
d) Decrease the current OSC and CHS Fail Low thresholds by the same amount of the span loss change calculated in
Step 5.
If an OPT-BST, OPT-AMP-C, or OPT-AMP-17-C is present:
• CHS Fail Low threshold refers to Port 2.
• OSC Fail Low threshold refers to Port 4.
If an OSC-CSM is present:
• CHS Fail Low threshold refers to Port 3.
• OSC Fail Low threshold refers to Port 6.
Step 9
For the two fibers belonging to the repaired span, identify the fiber for the east to west (E–W) line direction.
Step 10 Repeat the procedure from Step 5 to Step 8 for the E–W direction.
Step 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:
a) Go back to the Cisco TransportPlanner tool and open the network design configuration file.
b) Select Installation Mode to freeze the node layout and amplifier positioning.
c) Change the span value, inserting the new insertion loss that was measured in Step 3.
d) Run the Cisco TransportPlanner algorithm to validate the new design.
e) If the optical result indications (power, optical signal-to-noise ratio [OSNR], chromatic dispersion [CD], and so
on) are all green, the repair procedure is complete. If not, log into the Technical Support Website at
http://www.cisco.com/techsupport for more information or call Cisco TAC (1 800 553-2447) and report a
service-affecting problem.
If the LOS alarm is still present, continue with Step 12.
Step 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.
If an OPT-BST, OPT-AMP-C, or OPT-AMP-17-C is present:
• CHS Fail Low threshold must to be set to –30 dBm.
• OSC Fail Low threshold must to be set to –42 dBm.
If an OSC-CSM is present:
Cisco NCS 2000 series Troubleshooting Guide, Release 11.0
Corrective Action for Scenario 2
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