14-75
Cisco ONS 15327 User Documentation, R3.3
June 2002
Chapter 14 Alarm Troubleshooting
Alarm Procedures
Caution
Always use the supplied ESD wristband when working with a powered ONS 15327. Plug the wristband
cable into the ESD jack located on the lower-right outside edge of the shelf assembly.
Procedure: Clear the SF-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 SF 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-4.
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
Using an optical test set, measure the power level of the line and ensure it is within the 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 fail:
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 being used.
Step 6
Verify that a single-mode laser is being used at the far-end node.
Step 7
If the problem persists, the transmitter at the other end of the optical line may be failing and need
replacement.
14.4.107 SF-P
•
Not Alarmed (NA) (Condition)
A signal failure (SFP) alarm occurs when the quality of the signal is so poor that the BER on the
incoming optical line passed the signal failure (SF) threshold. Signal failure is defined by Telcordia as
a “hard failure” condition. SD and SF both monitor the incoming BER error rate and are similar alarms,
but SF is triggered at a higher BER than SD. The BER threshold on the ONS 15327 is user provisionable
and has a range for SF from 10
-5
to 10
-3
. SF-P causes a switch from the working card to the protect card
at the path (STS) level. A path or STS level SF alarm travels on the B3 byte of the SONET overhead.
The ONS 15327 detects path SF on the STS level, not the VT level.
The SF 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.
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 ...
