Thanks Jay!
That's the best I've seen from any of the posts. I've had exactly the same experience as you and am running a similar stack. STUN was no help and I'm baffled by NAT not working with appropriate rules in place even with reverse NAT in place. I'm using a static IP, and public FQDN for the server. I've never had success with NAT other than the in meeting room chat working. I had 1 day of success between my desktop and android device - full video and audio! But have not had any since with zero changes to my config. The last deep dive I took it looked like a conflict between the local FQDN (ie host.local) and the publci FQDN (host.domain.com).
The SIP portion works fine but you need at least 2 people in the room for it to dial out which has been a challenge. I've also not been able to screen share.
I haven't had a chance to play with Softether but will look into it.
Thanks Again!