So, passing over Bluetooth and internal WIFI is very easy (which was my first test a few weeks ago). I just started doing some WebRTC tests and looking at some server alternatives and signaling needs. It works but I am very early in this whole adventure.

I looked at Rendez-vouz as well and I was wondering can't we just pass the signaling through our usual relays instead? Maybe we still need some type of STUN server to get the phone's IP and as long as two users can use different STUN servers, it could work.

What I want to avoid is replacing our replays with a different "relay". If we need to use a server to transfer some info we can just use our regular relays instead to avoid another dependency/attacking point.