[throw14082020]

I always assumed everyone is behind NAT, you're saying on 10 to 20% of people are, and therefore only they need TURN. I'd love to see where you got that number.

If I were to guess, the problem GP is facing is bandwidth, a mesh network uses exponentially more bandwidth. For each user, the bandwidth is linear, N more people requires N more bandwidth. This is fine for downloads, but uploading N more can be much more challenging for certain networks.

[cma]

He's mistaken that NAT always requires TURN. Consumer NAT typically still allows incoming UDP, using STUN/punch-through, or TCP with uPNP support. He maybe meant to talk about only about more restrictive NAT situations or campus/corporate/ISP/nation-state/scientology-compound firewalls.

[throw14082020]

Im not sure about UDP hole punching and how it relates to WebRTC, i don't see it being talked about much. In general hole punching is a rare thing to hear, I cannot find much resources about it.

And uPNP (Universal Plug and Play) sounds like its for device discovery in the same local network, so again, it doesn't sound related to webRTC, we can connect directly with each other on the same local network anyway.

[mypalmike]

Hole punching in the context of webrtc is usually referred to as ICE.

UPNP has a number of functions, including forwarding of WAN packets to a specific LAN device.

[mypalmike]

The 10-20 percent would reflect people with symmetric NAT, which is rather common with mobile networks, corporate NAT, etc. Symmetric NAT requires TURN relays. Typical home router configurations are not symmetric NAT, and usually work with just STUN.