I purchased a PFsense firewall and was configuring it for SIPstation and had a weird issue. My trunks registered fine. Firewall test passed. If I made an outbound call I had perfect audio and functionality. But Inbound calls had NO outbound audio. The caller would never here the phone ringing in their ear and could not hear what I was saying no the local extension even though I could hear the caller fine.
I read multiple articles from Sangoma & Netgate among others with NO solution.
FINALLY, building on what I had read and what i got from Netgate TAC, I got it working. I wanted to post the configuration notes here incase it would help someone else.
Inbound port forwarding was simple and strait forward. The trick to get this to work was configuring Outbound NAT properly.
On the Outbound NAT specify a rule for the WAN interface allowing the PBX via UDP out to Destination (SIP trunk IPs) on Destination Port 5060-5061, NAT address = WAN address, NAT PORT = any, STATIC NAT checked
THEN make another rule for Outbound NAT for the WAN interface allowing the PBX via UDP out to Destination = any, Destination Port = any, NAT address = WAN address, NAT PORT = any, STATIC NAT checked
Hope this will help someone save all the time I spent.