WebRTC Receive-only Video without TURN

Question

I'm trying to set up a cost-effective home security camera site where I can login and view the stream with very low latency. WebRTC seemed like a great solution to get very low latency and keep the connection peer to peer.

I am looking to view this from a mobile device and as a client device I am often behind a symmetric NAT. Since I know the static public IP the camera is behind and control that network I believe I should be able to create a peer connection for video without the need for a turn server I am struggling to figure out how to manage the ICE portion in this case. When I try to connect with just STUN video does not work.

Given my control of the serving peer's network, should this be possible without TURN? If so is there a way for me to sidestep/implement ICE to establish video with my known server peer IP and configuration? Or is there a better technology to use altogether that would allow very low latency?

Answer 1

Knowing the IP address of the camera isn't going to help you any. Since you are dealing with a symmetric NAT, the NAT device is going to bind every IP:port from inside the network reaching to an IP:port in the external network.

This means that if you pin-hole the data via a STUN server, the NAT device won't be impressed enough by that feat to let you connect into the internal network from any other machine other than that STUN server.

Which leads to the fact that you'll probably need a TURN server...

That said, you might have some issues with how you've set up the STUN server and its configuration.

An easy and rather cheap approach can be to use Twilio NAT traversal service - https://www.twilio.com/stun-turn