User Manual

Cisco High-Density Analog Voice and Fax Network Module
Configuration Tasks
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Cisco IOS Release 12.2(2)XT and 12.2(8)T
To troubleshoot specific areas of the high density analog network module, perform the following steps:
• To show messages from the DSP on the VPM to the router, Use the debug vpm dsp .
• To show which debug commands are enabled, use the show debug.
• To enable the display of trunk conditioning supervisory component trace information, use the debug
vtsp all.
Troubleshooting Chart
Table 4 lists some problems you might encounter after configuring voice ports and some suggested
remedies.
Table 4 Troubleshooting Voice Port Configurations
Problem Suggested Action
No connectivity Ping the associated IP address to confirm connectivity. If you
cannot successfully ping your destination, refer to the Cisco IOS
IP Configuration Guide, Release 12.2.
No connectivity Enter the show voice port command with the voice port number
that you are troubleshooting, which will tell you:
• If the voice port is up. If it is not, use the no shutdown
command to make it active.
• What parameter values have been set for the voice port,
including default values (these do not appear in the output for
the show running-config command). If these values do not
match those of the telephony connection you are making,
reconfigure the voice port.
Telephony device buzzes or does
not ring
Use the show voice port command to confirm that ring frequency
is configured correctly. It must match the connected telephony
equipment and may be country-dependent.
Distorted speech Use the show voice port command to confirm that the cptone
keyword setting (also called region tone) is US.
Music on hold is not heard Reduce the music-threshold level.
Background noise is not heard Enable the comfort-noise command.
Long pauses occur in
conversation; like speaking on a
walkie-talkie
Overall delay is probably excessive; the standard for adequate
voice quality is 150 ms one-way transit delay. Measure delay by
using ping tests at various times of the day with different network
traffic loads. If delay must be reduced, areas to examine include
propagation delay of signals between the sending and receiving
endpoints, voice encoding delay, and the voice packetization time
for various VoIP codecs.