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
Resolving SS7 Network Related Problems
• Broadband ISUP (BISUP)
There are many variations of the different parts of the SS7 protocol stack. MTP has ANSI, ITU, Bellcore,
and several national variations. Each country and each major carrier might have slightly different
variations of a part to fit its particular needs.
The SS7 network must have the highest degree of reliability. Each switch with access to the SS7 network
must be configured to a preconceived set of network parameters. There is some risk that the person
configuring a switch is not using the correct set of parameters or values. Misconfiguration is the root
cause of most SS7 problems at both the MTP layers and upper layers of the SS7 protocol. A single
parameter value, such as an incorrect timer value, can cause SS7 connectivity to operate improperly or
fail completely.
The first, and most important, step in troubleshooting SS7 related problems is to understand, and fully
document, the SS7 network topology and protocols. The protocol documents are used as a reference over
the months and years of maintenance on the SS7 network.
The following sections describe troubleshooting SS7 network:
• Signaling Channel Problems, page 6-95
• Signaling Destination Problems, page 6-100
• Signaling Channel Troubleshooting Procedures, page 6-103
Signaling Channel Problems
The Cisco PGW 2200 Softswitch software generates signaling alarms if it detects problems with the
transportation of data on a signaling channel or at a signaling destination.
Signaling alarms have four classifications of severity:
• Critical
• Major
• Minor
• Informational
Note Multiple alarms are likely to occur for severe failures. For example, SUPPORT FAIL and SC FAIL would
typically occur with LIF LOS.
Signaling links are the dedicated communication channels that the Cisco PGW 2200 Softswitch uses to
transfer signaling information between itself, the Cisco ITP-Ls, and the Signal Transfer Points (STPs).
Signaling links provide the necessary delivery reliability for higher-layer SS7 signaling protocols.
You can use the Cisco PGW 2200 Softswitch software and MML commands to manage signaling
channels and lines. You can retrieve signaling channel attributes, change the states of signaling channels,
and change the state of signaling lines. See Chapter 3, “Cisco PGW 2200 Softswitch Platform
Operations,” for detailed information.
Note For more information on MML commands, see Cisco PGW 2200 Softswitch Release 9 MML Reference.
Because all types of signaling channels have basically the same functionality, you manage them
similarly. Unless otherwise noted, all commands, counters, and alarms that are documented in this
section apply to all types of signaling channels.