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I have a webcam chat room application (so it's many-to-many video sharing) using WebRTC and a mediasoup server.

I am having problems with SOME of my users not being able to get an incoming video feeds to work. It's a difficult problem because I can't reproduce it at all, and I can't easily "remote-debug" the problem since most of my users are very non-technical. So far the only thing I can tell for certain is that it seems to be network-related, not browser-related, as I have had bug reports from people using Firefox, Chrome, Safari, and Edge. I'm running my server (mediasoup v2) on port 443 with no firewall on the server box, so that should make the door as wide as possible. I just don't know what the exact problem is yet so I'm feeling around in the dark.

So, I'm trying solutions. I don't think(?) I have a TURN server set up but from what I have read, it seems like adding one certainly can't hurt, and could help with my situation.

I don't fully understand the entire WebRTC protocol or RFC 7118 (this stuff is really complicated!) or exactly what/where/how a TURN server fits into the bigger picture. It would help, right? A lot of Googling has led to no clear answers. Would love some help! Thank you!

Eric
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2 Answers2

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WebRTC tries everything it can do to make a p2p connection, but there are times that it will fail. The turn server acts as a last resort so that the peers can both connect through the turn server. Obviously this is not a p2p connection, so there will be extra latency, and you will have to make sure that your turn server has enough bandwidth to cover all of the connections you expect.

TL;DR, If you need 100% connection rates, you should have a turn server.

I believe AWS has a ready made instance you can spin up, or if you could use this open source coturn server https://github.com/coturn/coturn

On a debugging note... Check your ice candidates type. You should see host and srflx if you only have a STUN server, but if you have a TURN server you will also see relay. You can replicate this issue by discarding the ice candidates that have host and srflx types.

RooterTooter
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  • Thanks. I ended up signing up for Twilio, which has ready-to-roll TURN/STUN servers that are dirt cheap. My app does hundreds of hours of video/audio chat per month and I think my Twilio bill this month will be under US$1! – Eric Aug 30 '19 at 17:20
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I'm running my server (mediasoup v2) on port 443 with no firewall on the server box, so that should make the door as wide as possible

That is websocket. The media traffic runs over UDP typically and mediasoup uses random ports. A TURN server which is configured on udp port 443 may help in some cases. The other problem is UDP being blocked which is easy to reproduce with a local firewall.. Mediasoup supports something called ice-tcp which will allow media to run over a TCP connection. You should check if your mediasoup installation uses ice-tcp. If it does not, a TURN server with TURN/TCP will help.

Philipp Hancke
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