Troubleshooting guide

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Cisco PGW 2200 Softswitch Release 9.8 Operations, Maintenance, and Troubleshooting Guide
OL-0800-14
Chapter 6 Troubleshooting the Cisco PGW 2200 Softswitch Platform
Tracing
If you are experiencing problems with call processing and need to contact Cisco for support, you should
run a call trace before contacting Cisco TAC. The trace file helps the Cisco TAC troubleshoot the
problem more effectively. For some problems, the Cisco TAC cannot begin troubleshooting the problem
until you supply the trace file; so, it is a good practice to create this file before contacting them.
Understanding the Conversion Analyzer
The Conversion Analyzer is a viewer utility for .btr trace files. The Conversion Analyzer displays each
record from a .btr file in a readable form (ASCII text) that you can view with any text editor; however,
some useful sorting and display options are also available.
The .btr files serve as source files for .ca files. The .ca files are ASCII text output from the Conversion
Analyzer, which is obtained because of redirection of the standard output to a file. There are two main
sections in a .ca file. The header section contains a list of every signaling path that is defined on the Cisco
PGW 2200 Softswitch and a list of the message definition object (MDO) modules that are loaded. The
main body contains a printout of every record. Each record has a record number, a timestamp, a call ID,
and the print data that the record contains.
Understanding the Simulator Utility
The Simulator is a powerful MDO file processing utility that uses .mdo files to replay the events recorded
in a .btr file. The front end of the Simulator reads the .btr file. The interpreter in the Simulator utility
that loads the .mdo files and replays the events (.btr files) through the MDO, is the same interpreter that
the call engine uses in the Cisco PGW 2200 Softswitch when .mdo files are used. As the interpreter steps
through each line of object code (and the action of each object is interpreted) in the .mdo file, the utility
activates the print method of each object, which forms the next line of text in the .trc file.
The print method for each object contains text that directly relates to the appearance of the .mdl source
code that produced the object in the .mdo file (through compilation of the .mdl source code with the
MDL compiler). The .mdo files that are used with the Simulator when it is processing a .btr file to create
a .trc file, must be the same .mdo files that were in use when the .btr file was originally recorded on the
Cisco PGW 2200 Softswitch. This requirement defines why the conversion from a .btr file to a .trc file
is usually done on the Cisco PGW 2200 Softswitch that originated the .btr file.
The interpreter is not used with .so files because those files interact directly with the call engine in the
Cisco PGW 2200 Softswitch; but, the tracer can record a .btr file regardless of whether .mdo or .so files
were used to process the call. The Simulator can, however, replay .btr files by using .so files in place of
.mdo files. This capability of the Simulator provides a way of ensuring that the .so and .mdo files perform
the same way (although .so is faster).
Because .so files do not contain MDO objects, there are no print methods available to the Simulator, so
no .trc output is possible. When the Cisco PGW 2200 Softswitch produces a .btr file by using .so files,
the replay in the Simulator must be done with the .mdo files that were used to produce the .so files to
produce an accurate .trc file.
Understanding Trace Files
The Simulator utility produces trace files (.trc files), which are text files. Trace files contain detailed
line-by-line trace information from the MDO code that was run in the simulation replay that produced
the file, thus they contain MDL traces. The get_trc.sh script adds the .trc extension if the source of the
trace is a .btr file.
Trace files are source files for the SimPrint (SP) utility. Trace files are text files and can be viewed with
a text editor. You should send the .trc file to Cisco TAC if expert analysis is required.