14-73
Cisco ONS 15327 User Documentation, R3.3
June 2002
Chapter 14 Alarm Troubleshooting
Alarm Procedures
Procedure: Clear the SD-L Condition on an OC-N Card
Step 1
Verify that the user-provisionable BER threshold is set at the expected level:
a.
From the CTC node view, double-click the card reporting the alarm to bring up the card view.
b.
Click the
Provisioning
>
Line
tabs.
c.
Under the SD BER column on the Provisioning pane, check that the cell entry is consistent with
what the system was originally provisioned for. The default setting is 1E-7.
d.
If the entry is consistent with what the system was originally provisioned for, continue with Step 2.
e.
If the entry is not consistent with what the system was originally provisioned for, click the cell to
reveal the range of choices and click the entry that is consistent with what the system was originally
provisioned for.
f.
Click
Apply
.
Step 2
With an optical test set, measure the power level of the line to ensure it is within guidelines.
Step 3
Verify that optical receive levels are within the acceptable range.
Step 4
Clean the fibers at both ends for a line signal degrade:
a.
Clean the fiber according to local site practice.
b.
If no local practice exists, use a CLETOP Real-Type or equivalent fiber-optic cleaner and follow the
instructions accompanying the product.
Step 5
Verify that single-mode fiber is used.
Step 6
Verify that a single-mode laser is used at the far end.
Step 7
If the problem persists, the transmitter at the other end of the optical line may be failing and require
replacement.
14.4.105 SD-P
•
Not Alarmed (NA) (Condition)
A signal degrade (SDFP) alarm occurs when the quality of the signal is so poor that the BER on the
incoming optical line passed the signal degrade (SD) threshold. Signal degrade is defined by Telcordia
as a “soft failure” condition. SD and signal fail (SF) both monitor the incoming BER and are similar
alarms, but SD is triggered at a lower bit error rate than SF. SD causes the card to switch from working
to protect. The BER threshold on the ONS 15327 is user provisionable and has a range for SD from 10
-9
to 10
-5
. SD-P causes a switch from the working card to the protect card at the path (STS) level. A path
or STS level SD alarm travels on the B3 byte of the SONET overhead. The ONS 15327 detects path SD
on the STS level, not the VT level.
The SD alarm clears when the BER level falls to one-tenth of the threshold level that triggered the alarm.
A BER increase is sometimes caused by a physical fiber problem, including a poor fiber connection, a
bend in the fiber that exceeds the permitted bend radius, or a bad fiber splice.
Warning
Invisible laser radiation may be emitted from the aperture ports of the single-mode, fiber-optic
modules when no cable is connected. Avoid exposure and do not stare into open apertures.
Summary of Contents for ONS 15327
Page 22: ...Contents xxii Cisco ONS 15327 User Documentation June 2002 I N D E X ...
Page 30: ...Figures xxviii Cisco ONS 15327 User Documentation June 2002 ...
Page 44: ...Procedures xlii Cisco ONS 15454 Installation and Operations Guide R3 2 June 2002 ...
Page 540: ...Glossary GL 16 Cisco ONS 15327 User Documentation R3 3 June 2002 ...