Disable VAD/Silence suppression system wide

[Chuck Smith]

I went into the service parameters to disable VAD and our users can still here the phone cut them off every once in a while. Is there something else that you have to do in order to disable VAD/Silence suppression system wide?

[mschlenger]

If you are using h.323 as your signalling protocol on your gateways, issue a "no vad" under your dial-peer statements.

[Chuck Smith]

Wow what a fast response. Now that you mention it, yes I am using H323 on the gateway that they are complaining about. I will try that out on them tomorrow. Thanks allot.

Chuck

[dweiner]

Make sure you have an "incoming called number" statement on your representative dial-peer (the one with the "no vad" statement). If not, you'll still get vad on outbound calls as you don't have anything to match for the backward leg (voip) of the call. Here's the dial-peers that I've used successfully:

dial-peer voice 9 pots

destination-pattern 9

progress_ind alert enable 8

progress_ind progress enable 8

progress_ind connect enable 8

direct-inward-dial

port ?/?:?

prefix 9

!

dial-peer voice ?? voip

preference 1

voice-class h323 1

destination-pattern ????

incoming called-number .

progress_ind setup enable 3

voice-class codec 1

session target ipv4:???.???.???.??? //ip of CallManager

dtmf-relay h245-alphanumeric

ip qos dscp ef media

no vad

[Chester Rieman]

As an alternative, you can adjust the vad timer with the voice vad-time command. This adjust the amount of time that vad waits after detecting silence before supressing silence packets. So if you used a value of 30000 in the voice vad-time command(ms), vad would wait for 30 seconds before doing anything. You could set this really high and vad would really never activate. This is a global command so you don't have to worry about dial peers.

[giorgiosalsiri]

The last idea was probably the easiest to quickly determine where the issue is.