either end rings but no audio

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Jul 20th, 2010
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I am trying to set up my router and I have it at the point where I can call my phones but I get no audio. When I run my sniffer I see sip and register messages but I do not see any rtp from behind my router. It looks like a nat issue but I can not put my finger on it.

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Joseph Martini Sat, 08/07/2010 - 08:30
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I'm not sure what you mean by behind your router, is that the router your SIP phones are registering to?  The place to look for no audio would be between the two phones (packet capture at each phone).  Another thing to easily check is to try and ping between the IP address of the calling phone to the IP address of the called phone that will verify IP connectivity.  Then you want to check out any NATdevices in the path to make sure it can translate SIP messages to NAT the IP addresses within the signaling as well.  The same thing can be seen from the packet capture at each phone, just look into the SIP messages and make sure the wrong IP address isn't in there.


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