Forward Error Correction - Cisco NCS 2000 series Troubleshooting Manual

Forward Error Correction

Forward Error Correction
In DWDM spans, FEC reduces the quantities of retiming, reshaping, and regeneration (3R) needed to maintain
signal quality. The following two PM parameters are associated with FEC:
• BIT-EC: Bit errors corrected (BIT-EC ) indicates the number of bit errors corrected in the DWDM trunk
• UNC-WORDSThe number of uncorrectable words detected in the DWDM trunk line during the PM
Complete the following procedure to provision BIT-EC and UNC-WORDS PM parameters for FEC.
Provision Card FEC Thresholds
SUMMARY STEPS
1. In node view (single-shelf mode) or shelf view (multishelf mode), double-click a transponder, muxponder,
or xponder card to open the card view.
2. Click the Provisioning > OTN > FEC Thresholds tabs.
3. In the Bit Errors Corrected field, enter a threshold number, for example 225837.
4. In the Uncorrectable Words field, enter a threshold number, for example, 2.
5. In the Intervals area, click 15 Min.
DETAILED STEPS
Step 1
In node view (single-shelf mode) or shelf view (multishelf mode), double-click a transponder, muxponder, or xponder
card to open the card view.
Step 2
Click the Provisioning > OTN > FEC Thresholds tabs.
Step 3 In the Bit Errors Corrected field, enter a threshold number, for example 225837.
Step 4
In the Uncorrectable Words field, enter a threshold number, for example, 2.
Step 5 In the Intervals area, click 15 Min.
Sample Trouble Resolutions
The following sample trouble resolutions use PM and TCAs to isolate degrade points.
Problem
Solution
Solution
Solution
Cisco NCS 2000 series Troubleshooting Guide, Release 11.0
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line during the PM time interval.
time interval.
There is a BBE TCA on a single transponder pair.
The transponder input power is out of range.
Possible Cause
Check the input power on the transponder. It should be within the specified/supported range.
There are dirty trunk connectors on the transponder.
Possible Cause
Check the connector on the trunk port.
Possible Cause There is a degraded trunk patchcord between the transponder and the DWDM port.
Check the patchcord on the transponder DWDM port.
General Troubleshooting