no audion on Inbound call

Unanswered Question
Feb 15th, 2010

Hi Friends,

Outbound calling works fine.
When I receive an inbound call, the phone rings, but when I pick up the phone, the conversation does not get established.

I have call from inside NAT extension number to Outside NAT extension ( Outbout call ) then call get estabished and two-way audio work fine

but when I have call from Outside NAT extension to Inside NAT extension (Inbound call ) then  phone rings,

but when pickup the phone, audio is not present.

During inboud call RTP packets are not transmit whereas Outboud call RTP packets transmit successful.

Sometimes, Inbound and Outbound call only one-way audio present.

Can anybody help me, or point me to a previous thread where this issue was discussed and solved?

Thanks in advance.


Rajnikant Vanza

I have this problem too.
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mcampbellsmith Tue, 02/16/2010 - 02:20


Have you enabled STUN?  It could be that the SPA is passing an internal IP address as the RTP packet destination address.  If this is the case, you will not get audio.

Maybe its worth enabling some SIP debug traces and posting  the result here.  To do this, follow these  instructions:


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