Troubleshooting guide

BSR Troubleshooting Guide
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4. If LEDs on the POS module are green but you suspect that the module is has
transmission problems on a port (causing an LOS on the other SONET device
receive port), check for a Line Alarm Indication Signal (L-AIS) or Line Remote
Defect (Degrade) Indication (L-RDI) failure. To do so, view the Active Defect
field in the show controllers pos command output. An L-AIS and L-RDI failure
is generated by the other SONET device and sent out its transmit port when a
failure is detected on its receive port. An L-RDI can indicate an LOS failure
condition.
If there is no L-AIS ar L-RDI alarm, the problem may be with the other SONET
device.
5. Check for an L-RDI failure. To do so, view the Active Defect field in the show
controllers pos command output. An L-RDI failure is generated by the SONET
device and sent out its transmit port when a failure is detected on its receive port.
An L-RDI may indicate an LOS failure condition.
LOS Resolution
Follow these steps to resolve an LOS condition once the cause or problem area is
isolated:
1. Ensure that the fiber optic cable is properly connected throughout the line
between the receive port on the local POS module, regenerators, and the transmit
port on the remote SONET device.
2. If the optic cable is properly connected, check the fiber cabling for damage or
improper use. For example, SONET cables may be turned beyond their bending
radius.
3. Check for signal degradation.
4. Check fiber optic connectors for damage.
5. Ensure the fiber optic connectors are clean.
An LOS condition is cleared when a light source is present on the input.