Voice quality issue with PSTN calls

Unanswered Question
Nov 11th, 2003
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We are using the CallManager 3.3(3) and 2611 as the voice gateway. There are 8 analog lines connected to the 8 FXO ports on the router. Some users complaint that the valume will be drop down very low even mute for a few seconds and back up on the 7960 IP phone, so they may loose some information from PSTN caller.

I upgrade the IOS to 12.2.15ZJ3, but the problem looks still there. Is there any tune solution can address this problem on voice gateway? In the meantime, i am going to apply the sr2 to the ccm server, but i am sure if it is helpful.

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ahopkins Wed, 11/12/2003 - 05:13
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The fade in-fade out sounds like VAD. Are you sure VAD is turned off?

Depending on the direction of the Call: IP Phone to gateway or gateway to IP

Phone, you may be matching on different VoIP Peers. A couple of ways to

check this. On the gateway router, do a SHO VOICE CALL SUMM and see if the

VAD flag is set to Y or N.


============ ======== === ==================== ======================

1/0/1 - - - EFXS_INIT

If set to Y and you've turned VAD off on all of your VoIP Peers, then you

are matching the default Peer "0". This default peer is G729 codec and VAD

on. So you'd have to define a dummy peer that looks like:

dial-peer voice 1 voip

incoming called-number .

no vad

(note, G729 is the default codec above)

Hope this helps.

Leonlei Wed, 11/12/2003 - 06:38
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I am also thinking about disable vad on Voice Gateway and callmanager as well.


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