Sd-P - Cisco ONS 15327 User Documentation

Chapter 14 Alarm Troubleshooting
Procedure: Clear the SD-L Condition on an OC-N Card
Verify that the user-provisionable BER threshold is set at the expected level:
Step 1
a.
b.
c.
d.
e.
f.
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.
Clean the fibers at both ends for a line signal degrade:
Step 4
a.
b.
Verify that single-mode fiber is used.
Step 5
Verify that a single-mode laser is used at the far end.
Step 6
If the problem persists, the transmitter at the other end of the optical line may be failing and require
Step 7
replacement.

14.4.105 SD-P

•
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
to 10
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.
June 2002
From the CTC node view, double-click the card reporting the alarm to bring up the card view.
Click the Provisioning > Line tabs.
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.
If the entry is consistent with what the system was originally provisioned for, continue with Step 2.
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.
Click Apply.
Clean the fiber according to local site practice.
If no local practice exists, use a CLETOP Real-Type or equivalent fiber-optic cleaner and follow the
instructions accompanying the product.
Not Alarmed (NA) (Condition)
-5
. SD-P causes a switch from the working card to the protect card at the path (STS) level. A path
Cisco ONS 15327 User Documentation, R3.3
Alarm Procedures
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