Thanks for the response.
I would think a NAT issue would show up in other ways as well like not getting audio or the call dropping after 30-seconds. These calls are being dropped after 30-MINUTES. I talked to the SIP provider and what they indicated was that they are sending a re-invite but we aren’t responding with an ACK. They send the reinvite automatically at 30-minutes. They changed it to 60-minutes but that’s not a great solution.
Again I would think that NAT issues would exhibit other more immediate issues but we are seeing any of the traditional NAT issues.
When I look at the NAT settings I see that I have our public static IP as the External Address. I’ve also got all of our subnets listed in Local Networks. We are using PJSIP for our SIP trunks and extensions.