I'm having problems connecting to voipfone from FreePBX. I asked a question in the general hardware forum over at voipfoneuserforum.com, but I've got further debugging this, so I thought I'd post in here.
FreePBX is behind a NAT firewall.
I've set up NAT in SIP Settings and it autoconfigures correctly.
The OPTIONS packets have the external IP address in them, but the REGISTER packets have the internal IP address in the Call-ID. Voipfone responds with a 401 as expected but the Call-ID has the external IP address, so asterisk fails to match up the response and I get a timeout in the log. The cycle then repeats continuously.
I've rebooted the box. As the packets are flowing, and OPTIONS work OK, I assume the firewall is configured correctly.