Cisco ONS 15454 Troubleshooting Manual page 345

Chapter 2 Alarm Troubleshooting
Clear the LOF (EC1) Alarm
Verify cabling continuity to the port reporting the alarm. To verify cable continuity, follow site practices.
Step 1
Always use the supplied electrostatic discharge wristband when working with a powered ONS 15454.
Caution
Plug the wristband cable into the ESD jack located on the lower-right edge of the shelf assembly.
If cabling continuity is good, clean the fiber according to site practice. If no site practice exists, complete
Step 2
the procedure in the "Maintain the Node" chapter in the Cisco ONS 15454 Procedure Guide.
Step 3 If the alarm does not clear, see the loopback procedures in
isolate the fault causing the LOF alarm.
If the alarm does not clear, or if you need assistance conducting network troubleshooting tests, call
Step 4
Cisco TAC to report a Service-Affecting (SA) problem 1 800 553-2447.
2.7.205 LOF (OCN)
The LOF alarm occurs when a port on the reporting card has an LOF condition. It can also occur on
ONS 15454 MXP_2.5G_10G, TXP_MR_10G, TXP_MR_2.5G,TXP_MR_10E, or TXPP_MR_2.5G
cards reporting LOF. The alarm indicates that the receiving ONS 15454 has lost frame delineation in the
incoming data. LOF occurs when the SONET overhead loses a valid framing pattern for 3 milliseconds.
Receiving two consecutive valid A1/A2 framing patterns clears the alarm.
When the alarm is raised on an OC-N card, it is sometimes an indication that the OC-N card expects a
specific line rate and the input line rate source does not match the input line rate of the optical receiver.
Note For information about MXP or TXP cards, refer to the Cisco ONS 15454 DWDM Reference Manual.
Clear the LOF (OCN) Alarm
Verify cabling continuity to the port reporting the alarm.
Step 1
Always use the supplied electrostatic discharge wristband when working with a powered ONS 15454.
Caution
Plug the wristband cable into the ESD jack located on the lower-right edge of the shelf assembly. To
verify cable continuity, follow site practices.
If cabling continuity is good, clean the fiber according to site practice. If no site practice exists, complete
Step 2
the procedure in the "Maintain the Node" chapter of the Cisco ONS 15454 Procedure Guide.
If the alarm does not clear, see the loopback procedures in
Step 3
isolate the fault causing the LOF alarm.
November 2009
Default Severity: Critical (CR), Service-Affecting (SA)
SONET Logical Object: OCN
Chapter 1, "General Troubleshooting"
Chapter 1, "General Troubleshooting"
Cisco ONS 15454 Troubleshooting Guide, R8.5
2.7.205 LOF (OCN)
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