Cisco WAN Switching Modules

Field Notice: ABR Traffic Continuity Problem after switchyred

August 9, 2001

Products Affected




All Models with Firmware MFH or earlier.


All Models with Firmware MFH or earlier.

Problem Description

In redundant configurations, the standby Broadband Switch Module (BXM) may not be programmed with Available Bit Rate (ABR) connections which use Private Network-to-Network Interface (PNNI) partitions.


This problem manifests only if all the following conditions are met:

  • This problem will only occur in the networks that already have PNNI-ABR conns.

  • BXM or Enhanced Broadband Switching Module (BXM-E) must have MFH firmware or earlier.

  • Redundancy is added after ABR connections are added or the redundant card is not installed when ABR connection is added.

Problem Symptoms

The most observable symptom occurs when a recently upgraded BXM redundant pair experience a switchyred and ABR connections using PNNI routing lose connectivity.


Upgrade BXM or BXM-E to MFJ or later. Firmware MFJ may be obtained from CCO. Read BXM firmware release notes before upgrading from release firmware MEC (inclusive) and prior releases.


To follow the bug ID link below and see detailed bug information, you must be a registered user and you must be logged in.




ABR con have traffic continuity problem in case of switchyred.

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:

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