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Cisco ONS 15310-MA SDH Troubleshooting Guide, Release 9.0
78-18663-01
Chapter 2 Alarm Troubleshooting
Alarm Procedures
Step 3 If the BER threshold is correct and at the expected level, use an optical test set to measure the power
level of the line to ensure it is within guidelines. For specific procedures to use the test set equipment,
consult the manufacturer.
Step 4 If the optical power level is good, verify that optical receive levels are within the acceptable range. The
correct specifications are listed in the “Install Hardware” chapter in the Cisco ONS15310-MA SDH
Procedure Guide.
Step 5 If receive levels are good, clean the fibers at both ends according to site practice. If no site practice exists,
complete the procedure in the “Maintain the Node” chapter in the Cisco ONS15310-MA SDH Procedure
Guide.
Caution Always use the supplied electrostatic discharge wristband when working with a powered
ONS 15310-MA SDH.
Step 6 If the condition does not clear, verify that single-mode fiber is used.
Step 7 If the fiber is of the correct type, verify that a single-mode laser is used at the far-end node.
Step 8 Clean the fiber connectors at both ends for a signal degrade according to site practice.
Step 9 If the problem does not clear, the transmitter at the other end of the optical line could be failing and
require replacement.
Step 10 If the condition does not clear, log into the Technical Support Website at
http://www.cisco.com/cisco/web/support/index.html for more information or call Cisco TAC
(1-800-553-2447).
2.7.191 HP-DEG
Default Severity: Not Alarmed (NA), Non-Service-Affecting (NSA)
SDH Logical Objects: VCMON-HP, VCTRM-HP
An SD Path condition applies to the VC layer of the SDH overhead. A path or ST-level SD alarm travels
on the B3 byte of the SDH overhead.
For SNCP-protected circuits, the BER threshold is user-provisionable and has a range for SD from
1E–9 dBm to 1E–5 dBm. For 1+1/LMSP and unprotected circuits, the BER threshold value is not
user-provisionable and the error rate is hard-coded to 1E–6 dBm. An HP-DEG condition causes a switch
from the working port to the protect port at the path (VC) level.
The BER increase that causes the condition is sometimes caused by a physical fiber problem such as a
poor fiber connection, a bend in the fiber that exceeds the permitted bend radius, or a bad fiber splice.
SD causes the port to switch from working to protect. The SD condition clears when the BER level falls
to one-tenth of the threshold level that triggered it.
Clear the HP-DEG Condition
Step 1 Complete the “Clear the MS-DEG Condition” procedure on page 2-123.
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