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Cisco WAN Switching Modules

Field Notice: UVM with T1 Backcard is Stuck in Yellow Alarm When Using CCS


January 20, 2000


Products Affected

Product

TAN

IGX-UVM

Equipped with T1 interface.

BC-UVI-2T1EC

 

Problem Description

The UVM (Universal Voice Module) port will return a yellow alarm to the locally connected device, usually a Private Branch eXchange (PBX) or channel bank when the UVM port receives yellow alarm. Likewise, some PBXs detect yellow alarm and return yellow alarm. This combination results in a situation where neither the UVM port nor the PBX port can be cleared from the yellow alarm state without manual intervention by maintenance engineers.

If the PBX and IGX configurations are both set to Common Channel Signalling (CCS), this problem may appear when the channels on the PBX interface are manually put out of service, or when one of the channel Permanent Virtual Circuits (PVCs) terminating on the UVM fails.

Background

This problem occurs only when the CCS feature is enabled via the cnflnsigparm command:

12 CVM & UVM Condition T1 Lines? [ YES]

This problem occurs only in 9.2.30 and earlier versions of 9.2. This problem does not occur in any 9.1 or earlier versions of software since the feature was not available in those releases. 9.3 software, currently unreleased and under development, has the fix for this problem.

This problem is caused by software. UVM card replacement will not resolve this problem.

Problem Symptoms

Network users will not be able to establish calls through the affected T1 interfaces because the attached PBXs will busy out the channels on the T1 interfaces detecting yellow alarm.

Network maintenance staff will observe that the T1 line is stuck in yellow alarm. Yellow alarm is also known as Remote Alarm Indication (RAI) and is a standard T1 interface alarm. The alarm condition may be observed by executing the following commands and observing the resulting output:

dspalms

igxnode     TN   StrataCom     IGX 8430  9.2.23   Jan. 14 2000 16:26 GMT 
Alarm summary   (Configured alarm slots: None)
Connections Failed:       None
TRK Alarms:               1 Major
Circuit Line Alarms:      1 Major  <<-- Note Alarm State.
Physical Line Alarms:     None
Cards Failed:             None
Missing Cards:            2
Remote Node Alarms:       1 Major  

Interface Shelf Alarms:   None   

FastPAD/Access Dev Alms:  None 

Last Command: dspalms  

Next Command:
                                                           MAJOR ALARM

dsplns

igxnode     TN   StrataCom     IGX 8420  9.2.23    Jan. 14 2000 15:32 GMT  
 Line       Type   Current Line Alarm Status
 9.1        T1/24  Major - Rmt Oof (YEL)

dsplog

Major  LN 23.1 Rmt Oof (YEL)              01/14/00 04:37:50

Attempts to clear the yellow alarm may fail.

Workaround/Solution

Workaround:

The yellow alarm may be cleared by executing the following steps:

  1. Delete connections delcon slot.port.channel

  2. Down the line dnln slot.port

  3. Reconfigure the lines cnfln slot.port

  4. Disable the feature cnfclnsigparm 12 N

Solution:

Upgrade to the next release of software 9.2.3x with the fix for this bug. As of the publication of this Field Notice, the bug (CSCdp59960) is resolved but not integrated into a release of 9.2 software. If you are a registered CCO user and you have logged in, you can use the hyperlink below to observe the status of this bug. Use the Bugwatcher feature available on CCO to obtain proactive email notifications of this bug`s status changes.

DDTS

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

DDTS

Description

CSCdp59960 (registered customers only)

UVM does not send yellow-alarm to PBX when it receives a yellow-alarm from PBX

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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