No audio for incoming calls

We have a trixbox 2.8 server that we just put in. The server is behind a Sonicwall firewall with 10 IP phones. The phone system is connected to the outside world through a SIP trunk. The trunk is registering just fine and so are the phones. We can call into the phone system and we get two way audio. The problem we are having is when we call out from the trixbox we get no audio on both ends. The call completes just fine but we just can’t hear anything on either side. We have turned off everything SIP on the firewall, triple checked sip_nat.conf and still can’t figure it out. According to our SIP provider, we aren’t sending the port with our contact IP which means we can’t get any further in the translations. Here is the information they provided us:

Your contact field is missing the port on it, without that you can’t build further into the translations:


My Test phone:
Contact: “0987654321”

Obviously the Xs represent the external IP address. Also, here is a copy of our sip_nat.conf:


Any ideas on what may cause this?


open the ports for RTP,SIP 5060 and check the IPtable if you enabled that.

Sounds to me as though the router is translating the port number. You should not let it do this, or you should run a SIP proxy on the router.