Thanks again for elaborating it’s very much appreciated.
However, I’m still unconvinced whether port forwarding is required to get FPL working with an * box and I sincerely mean no disrespect with regards to your explanation. Also, I never mentioned my * box was in the DMZ, it’s on the private LAN. I also don’t have a router, pfSense is my router configured as a VM in my ESXi box and connected to switches - not sure if pfSense has a “SIP ALG” option though, will take a look. Rebooting generally fixes incoming, I can make normal calls and hear audio in both directions.
Please excuse my ignorance but isn’t port forwarding, and using your words, inviting external forces to attack the box and penetrate my communications system? Of course in a perfect world, I’d rather not port forward. And to be frank your explanation kind of contradicts the plethora of accounts I’m seeing of users getting * working without port forwarding - of course some may be using different VoIP providers.
My knowledge may in fact be limited as it pertains to firewalls and VoIP data in general, but as it stands now, I’ve got it running without port forwarding. And it appears as though I’m able to get incoming calls without the aforementioned issue. It’s been stable for more than a couple of days, which wasn’t the case when I first posted - we’ll see how this progresses over time…
Quite honestly, I’m not sure what setting did it. I applied the settings as per my previous post and altered the useragent just for good measure. More so, I did the following: registered a dynamic DNS setup, configured pfsense to keep my ddns updated on what my public IP address is and configured Asterisk so that it knows its outbound trunk connection is being natted, and that the public IP address can be found by looking up the dynamic domain. Perhaps the NAT=YES IS enough in this case.
I am however very grateful for your input and explanations and your time is extremely appreciated.