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G729 Silence trimming /detection

We have a Unity VM only installed with g729 only(all calls, prompts and recordings G729). Customer reports that once a caller records a message the system does not recognise the silence as the end of the msg - it therefore does not give any further options, just records silence. Are there isssues with G729 silence detection? Any workarounds? Unity 4.21, CCM4.1



Re: G729 Silence trimming /detection

Are you getting this error in the Unity Application log?

Event Type: Information

Event Source: CiscoUnity_Miu

Event Category: Information

Event ID: 634


[Port 1] Recording stopped due to leading silence time out.

If yes, then it could be a routing issue, I recommend you to take a sniffer trace on the phone that is trying to leave the voicemail with matching sniffer trace on the Unity server to see what is going on.

Community Member

Re: G729 Silence trimming /detection


thanks for your reply, unfortunetly no obvious errors like that in the app log.

Could CSCse60536 be causing this ? If so do Cisco have a pre recorded prompt which includes the press # at the end of the msg on it ?

Cisco Employee

Re: G729 Silence trimming /detection

First, yes - G729a cannot do silence detection - one of the reasons the codec is so compressed is it weeds out all silence and you can't easily detect it on the fly as you can with other codecs. That's expected.

Which prompt are you talking about? On my 4.2(1) system it does say press # when you're done in the system prompt for recording - which one are you hearing?

Community Member

Re: G729 Silence trimming /detection

Jeff, apologies, wrong info here, its Unity 405.

Cisco Employee

Re: G729 Silence trimming /detection

Ah, that makes sense - several prompts were changed to include the "#" references in 4.1 and 4.2.

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