I need some help to better understand how networks work, ports, and communication. Suppose we have this situation:
We have on the left a corporate network (let's call it "A") which has a DMZ with a server exposed to the public Internet (public IP), and on the right another corporate network (let's call it "B").
Commonly corporate networks has Symmetric NAT (isn't that correct?).
My goal is to create a video conference application to let a host in A communicate a host in B.
Talking about VoIP, is it enough to install a VoIP proxy server (e.g. Asterisk) in 10.10.0.0 to let hosts communicate? I would open the required ports for 10.10.0.0 for inbound and outbound traffic. Do I need TURN or STUN? I hope I've been enough clear, but the situation it's not clear to me, so in case help me to better explain.