Troubleshooting guide

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Cisco Broadband Local Integrated Services Solution Troubleshooting Guide
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Chapter 9 Troubleshooting Cisco Media Gateways
Troubleshooting VISM Cards
Typically, both SCCs run the same software image. However, it is possible for SCCs not to run the same
software image when there is only 1 SCC in the node and you tftp a different image to the SCC, and then
insert another SCC which has an old image. In this case, the active SCC will check the image file
checksum and transfer the image file from Active to Standby if they are different.
You must reset the Standby SCC after the file transfer. To check whether the Active and Standby are
running different images, use “lscds”command and verify the software version.
Each SCC has a hard-disk on board. This hard-disk houses the persistent database (called HD-DB) in a
set of files. The non-persistent database (also called RAM-DB) is stored in RAM files and are not
restored if the node is reset/rebooted. Persistent database includes fast-ethernet lines configured on SCC,
the number and type of service cards present in the node, the service-card redundancy configuration, the
DS1 to DMC-DS3 mappings. The SCC hard disk also houses all the service card HD-DBs because
service cards do not carry hard disks. Besides, if the configuration is stored on SCC, then it is easy to
replace a faulty service-card with a new service-card.
Standby SCC Stays in Mismatch State
This occurs when the Standby SCC configuration does not match the Active SCC configuration. Both
SCCs should have identical configuration, such as BIM-type, BC-type, DMC, etc. This problem can be
caused by any of the following:
1. If your previous Standby SCC had a 4-FE BIM and you replaced it with OC3 BIM.
2. If you replaced your 4-FE Standby SCC backcard with OC3 SCC backcard.
3. If you have a DMC with the Active SCC and you do not have a DMC with the Standby SCC. If you
donot have a DMC with the Active SCC, you must unplug the DMC that is with the Standby SCC.
Standby SCC Goes to FAIL State
This problem can be caused by a variety of reasons, such as when DB Sync to standby SCC fails, DMC
initialization on Standby SCC fails, DBM update to standby SCC fails, etc. This should be a rare
occurrance and should be logged with the following information:
1. Output on Active SCC of “lscd” command for Standby SCC
2. Output on Active SCC of “lscds” command
3. Output on Active and Standby SCC of “lsevt” command
4. Screen dump of Active and Standby SCCs at the time of failure if available
5. Version of both SCCs
Troubleshooting VISM Cards
Use the following troubleshooting tools and techniques to assist you in maintaining your VISM card:
• “VISM Card LEDs” section on page 9-32
• “VISM and PXM Display, Log, and Diagnostic Loopback Path CLI Commands” section on
page 9-34
• “VISM Alarms” section on page 9-36
• “UNIX Snoop Trace Tool” section on page 9-36
• “Symptoms and Solutions” section on page 9-37