Troubleshooting guide

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Cisco PGW 2200 Softswitch Release 9.8 Operations, Maintenance, and Troubleshooting Guide
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Chapter 4 Maintenance and Troubleshooting Overview
Troubleshooting Strategy Overview
• Replacing hardware components—Maintenance chapter for each element of the Cisco PGW 2200
Softswitch platform includes sections that describe how to replace the field-replaceable components
of that device. You swap out components of a device to replace defective components and to upgrade
hardware.
Troubleshooting Strategy Overview
The Cisco PGW 2200 Softswitch platform supports connections to external switches and to internal
components, such as Media Gateway Controllers, signal processors, and trunking gateways. The Cisco
PGW 2200 Softswitch platform functions in a complex environment, which involve numerous
connections, links, and signaling protocols. When connectivity and performance problems occur, they
can be difficult to resolve.
Troubleshooting usually consists of determining the nature of a problem and then isolating the problem
to a particular device or component. When a problem is isolated and identified, troubleshooting also
requires fixing the problem, usually by replacing the device or some component of the device. This
chapter provides general troubleshooting strategies, as well as information about the tools available for
isolating and resolving connectivity and performance problems.
Symptoms, Problems, and Solutions
System problems show certain symptoms. These symptoms can be general (such as a Cisco SS7 interface
being unable to access the SS7 network) or specific (such as routes not appearing in a routing table).
Determine the cause of a symptom by using specific troubleshooting tools and techniques. After
identifying the cause, correct the problem by implementing a solution that requires a series of actions.
General Problem-Solving Model
A systematic approach works best for troubleshooting. Define the specific symptoms. Identify all
potential problems that could be causing the symptoms. Then systematically eliminate each potential
problem (from the most likely to the least likely) until the symptoms are no longer present.
Figure 4-1 illustrates the process flow for this general approach to problem-solving. This process is not
a rigid outline for troubleshooting. It is a guide that you can use to troubleshoot a problem successfully.
The following steps describe in more detail the problem-solving process that is outlined in Figure 4-1:
Note You need to determine and understand the message flow for certain actions. You might need to use
different tools for situations in which messages are exchanged within the Cisco PGW 2200 Softswitch
software or the operating system (UNIX), and situations in which messages flow between the Cisco
PGW 2200 Softswitch and the external nodes over IP.
Step 1 When analyzing a problem, draft a clear problem statement. Define the problem in terms of a set of
symptoms and the potential causes of those symptoms.
For example, the symptom might be that the EQPT FAIL alarm has become active. Possible causes might
be physical problems, a bad interface card, or the failure of some supporting entity (for example,
Layer 1 framing).