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hissing and static

Unanswered Question
Dec 22nd, 2006
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We have a customer with a new IPTD installation...they are connected to the telco through a PRI...

We seem to have an issue with noise being injected into the conversation during seconds of silense...

Vad has been disabled on all voip dial-peers....Silense suppression is set to False in CallManager...

If I am talking from the PSTN to someone on an IP phone and I count from 1 to 5 with a brief (~2 second)

pause the static comes in....and the static is almost uniform...

What makes this even more odd is that it only happens when the call is originated from the IP phone...

If the call comes in from the PSTN there is no issue....Does any have an experience with this or a method to troubleshoot it to find out where the noise...



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wdrootz Thu, 12/28/2006 - 11:39
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1.) What codec are they using between sites?

2.) How many calls are up during any give time?

3.) What is the voice quality issue? Is it both directions?

dgahm Thu, 12/28/2006 - 14:50
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Sounds like a DSP problem to me. Normally inbound calls start at PRI channel 1 and work up while outbound calls start at 23 and work down. Since your problem is outbound the DSPs associated with the PRI high channels may be faulty.

A couple commands that may be useful:

show voice dsp

show voice dsp errors

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