[subins2000]

WebRTC connection requires the peers to exchange signal data. This can be through a middleman server, Qr code or even pen & paper.

I've made a library that uses WebTorrent trackers to exchange the signal data and make P2P connections : https://github.com/subins2000/p2pt

[elwebmaster]

Signalling through QR code or pen & paper while possible in theory is not feasible in practice because both sides need to exchange ICE candidates & offer/answer. So a signalling middleman, whether through websockets, SSE, polling, etc. is needed. And if you want to support network handoff then you need persistent connection to the signalling server for re-negotiation.