Peer to peer simply doesn't work since NAT. Skype used to be peer to peer but they backpedaled a while ago because this and more reasons that simply made p2p obsolete and broken.
It's too long to cover in one message. Would you be interested if I write a blog post? How peer to peer architecture became obsolete and why no software is using it.
Ya, I'd be interested in reading that! Could you address why it wouldn't work with NAT the same way bittorrent deals with it? I'm probably missing something, but I don't see why bittorrent can work so easily but video conferencing cannot. thanks
Edit: Does bittorrent require you to port forward? I didn't think it did, but I haven't seen it configured in years so maybe I am forgetting that step
In a scenario of 12 people video chatting around the world, I don't believe you could guarantee consistent high-speed connections between the involved parties.
Teredo tunneling was one of the coolest solutions to this problem, providing both NAT-busting and IPv6 support but unfortunately it never gained popularity.