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
Step 6 Modify the priority settings of the link by entering the prov-ed:c7iplnk:name=“lnkname”,pri=1
command.
Where:
lnkname—Name of an SS7 link that is not set to priority 1.
Repeat this step for each link that is not set to priority 1.
Step 7 If any of the SS7 routes show a priority other than 1, change the priority settings to ensure proper route
load sharing. Before changing the priority settings for the route, take the route out-of-service, as
described in the “Setting the Service State of an SS7 Signaling Service” section on page 6-104.
Step 8 Modify the priority settings of the link by entering the prov-ed:ss7route:name=“rtname”,pri=1
command.
Where:
rtname—Name of an SS7 route that is not set to priority 1.
Repeat this step for each route that is not set to priority 1.
Step 9 Save and activate your provisioning changes, as described in the “Saving and Activating your
Provisioning Changes” section on page 3-65.
If the condition clears, the procedure is complete. Otherwise, proceed to Step 10.
Step 10 Contact the Cisco TAC to analyze the problem further and to determine a solution. For more information
about contacting the Cisco TAC, see the “Obtaining Documentation and Submitting a Service Request”
section on page xviii.
Physical Layer Failures
The major issues pertaining to the physical layer of an SS7 signaling link are related to cabling, clock
source, and connector pinouts. The cable should be of high quality (shielded) and the connectors should
be attached and crimped solidly. Because SS7 links are synchronous, one side of the link must provide
the clock source and the other side must use this clock signal to read the bits.
The most common mistake is to use the wrong cable pinouts for a specific physical configuration. Make
sure that the connector has the correct number of pins (RJ-45, DB-25) and that each pin maps to the
correct signal. Several physical layers are supported, including ANSI T1, CEPT E1, and V.35. Ensure
that the cable complies with the connector and the physical protocol being used.
If the configuration appears to be valid and the cable pinout is good, check that the signal is being sent
and received correctly. Use a Bit Error Rate Tester (BERT) or perform a signal loopback on the interface.
It is possible that the cable is bad, so try to replace it. The line card might be defective, so consider
replacing it.
Configuration Errors
The most common mistake in SS7 signal link configuration is to misconfigure the Signal Link Code
(SLC) for the SS7 link. The SLC is a preconfigured code on both ends of the link. If the SLC or the point
codes do not match, the link does not align and no transmission can take place.
For T1 and E1 connectors, an SS7 signaling link is carried in a single 56- or 64-kbps time slot. The time
slot that is used must also match on both sides of the link.