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
Understanding SimPrint
SimPrint (SP) is a utility for viewing .trc files. SP converts a .trc file into a sequence diagram that shows
all of the external and internal events that occur in a .trc file. The sequence diagram is useful for getting
an overview of what is occurring in the trace.
The following list defines the terms that are used in the call flow printouts, which the SimPrint tool
generates:
• LINE—Incoming and outgoing interfaces of the Cisco PGW 2200 Softswitch.
• OCC—Originating Call Control state machine. The call is passed from the incoming interface to a
protocol adapter, where it is converted into a generic message signaling unit (MSU) and sent to the
OCC for parsing of MSU data to memory.
• LCM—Lightspeed Call Model state machine. The LCM is a generic call model, which contains
event handlers to process generic call event data. This processing includes generic call analysis,
requests for bearer channels, and transfer of the MSU to the appropriate TCC state machine. The
LCM is also known as the Universal Call Model (UCM).
• ANALYSIS—LCM can perform generic call analysis that is based on the content of the MSU. The
LCM exchanges data with the call processing engine to analyze the MSU. After analysis is
complete, an available circuit is identified and the LCM sends a bearer channel seizure request
message to the CPM state machine.
• CPM—Connection Plane Manager state machine. The CPM exchanges data with the call processing
engine to seize and prepare a bearer channel for routing of the call data.
• CDR—Call Detail Record. CDR information is created because of LCM processing of the MSU.
• TRIGGER—Intelligent Network (IN) Trigger state machine. This state machine to sends and
receives IN trigger events to the Transfer Capabilities Application Part (TCAP) interface in the I/O
channel controller (IOCC). This ability to send and receive IN trigger events enables the tool to send
IN messages to a service control point (SCP).
• ENGINE—Call processing engine exchanges data with the LCM as generic call analysis is
performed on the MSU and a bearer channel is seized and prepared for routing of the call data.
• TCC—Terminating Call Control state machine. The TCC changes the call data into a
protocol-specific protocol data unit (PDU) and passes the PDU to the terminating IOCC for routing
to the outgoing interface.
Alternatives to Call Tracing
Performing call traces to identify problems can be difficult. A trace can gather much data before the error
occurs. Traces can negatively affect system performance. The Cisco PGW 2200 Softswitch software has
MML commands that you can use to diagnose problems with hung calls and abnormal call termination.
The following sections describe the commands.
Diagnosing Hung Calls
You can print the diagnostic information about hung calls to a file by issuing the prt-call MML
command. The contents of the file include all the previous states of the call and a history of occurrences
leading up to the call being stuck in its current state.