Sf-L - Cisco ONS 15327 User Documentation

Alarm Procedures
Always use the supplied ESD wristband when working with a powered ONS 15327. Plug the wristband
Caution
cable into the ESD jack located on the lower-right outside edge of the shelf assembly.
Procedure: Clear the SD-P Condition on an OC-N Card
Step 1 Verify that the user-provisionable BER threshold is set at the expected level:
a.
b.
c.
d.
e.
f.
With an optical test set, measure the power level of the line to ensure it is within guidelines.
Step 2
Verify that optical receive levels are within the acceptable range.
Step 3
Verify that single-mode fiber is being used.
Step 4
Step 5 Verify that a single-mode laser is being used at the far end.
If the problem persists, the transmitter at the other end of the optical line may be failing and require
Step 6
replacement.

14.4.106 SF-L

•
A signal failure (SFL) 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
at the line (facility) level. A line or facility level SF alarm travels on the B2 byte of the SONET overhead.
SF causes a card to switch from working to protect at either the path or line 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.
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.
Cisco ONS 15327 User Documentation, R3.3
14-74
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.
Not Alarmed (NA) (Condition)
-5 -3
to 10 . SF-L causes a switch from the working card to the protect card
Chapter 14 Alarm Troubleshooting
June 2002