Field Notice: *Expired* FN - 13893 - ONS 15454 BLSR - OC-N Card Pull and Insert with LOS/LOF Drops Traffic on Revert

Revised October 10, 2006

June 18, 2001

THIS FIELD NOTICE HAS BEEN ARCHIVED AND IS NO LONGER MAINTAINED OR UPDATED BY CISCO.

THIS FIELD NOTICE IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE, WARRANTY OR SUPPORT. USE OF THE INFORMATION ON THIS FIELD NOTICE OR MATERIALS LINKED FROM THIS FIELD NOTICE IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS FIELD NOTICE AT ANY TIME.

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Products Affected

Product	Comments
ONS 15454 Release software	Version 2.2.0 and 2.2.1

Problem Description

If an OC-N trunk card participating in a Bidirectional Line Switch Ring (BLSR) is removed from a node, traffic on that card switches to the protect path, as expected. If the OC-N trunk card is then reinserted while there is still an outstanding SF (Signal Fail) alarm, then once the card boots and the Wait to Restore (WTR) timer expires, traffic switches back to the card, making it active. As the card is still in a signal failure condition, traffic is lost. (An SF alarm can be generated as the result of a pulled or damaged fiber.)

Background

This problem was identified in the field and verified in our labs.

Problem Symptoms

Traffic loss after the re-insertion of a OC-N card that was participating in a BLSR.

Workaround/Solution

Workaround:

If the node participates in a BLSR configuration and you experience an loss of signal (LOS) condition on an OC-N trunk card, apply a "Forced Switch" away from the affected span (at both nodes) prior to troubleshooting. Note that even though a ring switch might have already occurred, issuing the Force ensures that traffic will not inadvertently switch back to the failed span before the problem is resolved.

After you clear the LOS condition (for example, by repairing a bad fiber or replacing a bad OC-N trunk card) you can remove the Force Ring and resume normal traffic flow.

Solution:

This issue is resolved in Release 2.2.2.

DDTS

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DDTS	Description
CSCds91558	BLSR - OCn card pull and insert with LOS/LOF drops traffic on revert

For More Information

If you require further assistance, or if you have any further questions regarding this field notice, please contact the Cisco Systems Technical Assistance Center (TAC) by one of the following methods:

• Open a service request on Cisco.com
• By email
• By telephone

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