Troubleshooting guide

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Cisco PGW 2200 Softswitch Release 9.8 Operations, Maintenance, and Troubleshooting Guide
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Chapter 6 Troubleshooting the Cisco PGW 2200 Softswitch Platform
Tracing
The script then displays a list of commands and prompts you to enter a command. The script lists the
following commands:
• S—Displays the call trace data using the SimPrint utility. For more information on SimPrint, see the
“Understanding SimPrint” section on page 6-165.
• F—Displays the call trace data using the SimPrint utility, and a listing of the sent and received fields.
• D—Displays the data in the .trc file associated with this call trace. For more information on .trc files,
see the “Understanding Trace Files” section on page 6-164.
• C—Converts the file that this script creates to a .trc file.
• A—Displays the data in the .ca file associated with this call trace. For more information on .ca files,
see the “Understanding the Conversion Analyzer” section on page 6-164.
• N—Displays the information for the next call ID in the list.
• P—Displays the information for the previous call ID in the list.
• L—Lists all the call IDs in the data for this call trace.
• H—Provides help on displaying call trace data.
• Q—Closes the script.
• id—Displays the information for a call ID that you specify.
Deleting Call Trace Files
Call trace files can be rather large. Leaving these files on your disk after you no longer require them
could raise capacity issues. Delete call trace files by issuing UNIX commands, as described in the
“Deleting Unnecessary Files to Increase Available Disk Space” section on page 6-169.
Understanding the Call Trace
Call traces record information in a trace file that shows how the Cisco PGW 2200 Softswitch processed
a specific call. Traces are most useful when you can be sure that a problem call is reaching the call engine
and starting an instance of a Message Definition Language (MDL) state machine. You can determine
whether the problem call is reaching the call engine by looking for the presence of non-idle circuits
(rtrv-cic) or “new cmgCall” entries in the debug logs.
After you start a trace, all call-processing activity for calls originating from the specified destination is
captured. The trace enables you to follow the call through the Cisco PGW 2200 Softswitch to discover
where it fails.
The trace output is in binary format. It shows:
• PDU that the Cisco PGW 2200 Softswitch receives
• How the Cisco PGW 2200 Softswitch decodes the PDU
• PDU that the Cisco PGW 2200 Softswitch sends
Using call trace logs is uncomplicated if you remember how to locate the record of a call:
• You can locate incoming signal messages that start instances of engine call objects by searching
backwards in the call trace for “new cmgCall.”
• Similarly, you can find the end of a call by searching forward from the “new cmgCall” message for
the next “end cmgCall” message.