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New Member

729 Codec stops working with Unity 3.1.5

I have an installation with a callmanager and phones in one location and unity in another. When the codec is configured for 729 the calls to unity eventually stop working. If you watch the status monitor you see the call come into Unity but the IP Phone user hears nothing but silence. If you change the codec to 711 the calls into unity work and never fail. If you change it back to 729 it will work for a while and then revert back to the previously described behavior.

New Member

Re: 729 Codec stops working with Unity 3.1.5

It seems to have to do with capacity. Yesterday I had two phones in a 729 region. They worked flawlessly all day. At the end of the day I put the other 100 + phones back in the 729 region. By this morning all phones have started failing again. When I put the phones back in the 711 region (with the exception of the two test phones) all phone begin to work again including my test phones. (I think this has to do with the fact that my voicemail ports got reset). Previously a reboot of the Unity server would produce would cause all 729 phones to begin working for a short while.

It seems to be completely codec related. I have a direct dial into the Unity server via a voice gateway that is local to the unity box. I can make the region Unity is in 729 with region and the problem exists with I dial directly into the gateway at the unity site. When I make it 711 again it begins to work.

I have ran the setWavFormat utility to save my prompts to 729 and it doesn't seem to make a difference. I have reran the sl_g729a_setup.exe app and rebooted the server. Again it doesn't change the behavior. Please help.

Cisco Employee

Re: 729 Codec stops working with Unity 3.1.5

Try installing the latest G.729 codec from the Unity 4.0 CD's. It is also available at


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