How to detect drop calls and voice quality issues

jhun_puyong · ‎07-28-2010

Hi VoIP Guru's,

Can someone share the troubleshooting tip to determine/detect drop calls and how to fix or deal with it. I usually use "show call active voice brief command". Hopefully you can share some other helpfl commands that I can use for troubleshooting.

Thank you and really appreciate the help.

Steven Holl · ‎07-29-2010

The best thing to track causes of dropped calls is to proactively run 'debug voip ccapi inout' to the router's logging buffer. You can then grep the log for cause calues with: sh log | i alue=

The cause values are the q.850 reason codes, and shed light on why the call drops. If you have an h323 gateway, 'sh h323 gateway cause' is also useful.

For voice quality issues, troubleshooting is very circumstantial. It depends on the topology, and which side is hearing the issue. If you had quality issues being heard by the PSTN caller you could look at:

sh call history voice brief

sh controller t1/e1

If there is a WAN router or any device doing L3 QoS for voice:

sh policy-map int

There was a troubleshooting voice quality presentation at Cisco Live! this year, which you may want to check out for a methological approach to troubleshooting voice quality.

jhun_puyong · ‎08-03-2010

Hi Steven,

Thank you for informational tips you have given me.. I'll check out the Cisco Live.

Have a wondeful day!