Voice is not heard when calls through internet are answered

Unanswered Question
Apr 16th, 2007
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Please it is urgent. I have a call manager express natted to a real IP. This real IP is used by users from other remote sites (in Dubai), in order to register to the CCME and call our extensions in Beirut. The IP phones (IP communicator) are registering, and are able to call each other(the phones are ringing), but we can't hear each other when we answer the calls, no voice is heard.

Please advice urgently (maybe it is ports problem or ... ???!!)


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johnnylingo Mon, 04/16/2007 - 07:59
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What ports are open on the public IP? You'll need to open TCP 2000 for SCCP and also UDP in the range 16384 - 32767 for RTP traffic.

tarek issa Tue, 04/17/2007 - 03:18
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I m using the mtp command.And i have red the following:

"If a firewall is present, it can be easily configured to pass the RTP packets because the router uses a specified UDP port for media packets. In this way, RTP packets from remote IP phones can be delivered to IP phones

on the same system though they must pass through a firewall".

So which port should the firewall open if i m using mtp? Should UDP be always opened for all ports ?

johnnylingo Tue, 04/17/2007 - 06:33
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Unfortunately, I don't know as I haven't worked with CCME.

What do the firewall logs show?


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