Sequence of offer/answer in WebRTC P2P mesh topology

Question

I am using a web socket server (node JS) to act as a signaling server. I want to create a P2P mesh network - everyone is connected to each other.

What would be the order of operations/events when:

1. The 1st peer joins
2. The subsequent peers join

Do every connecting peer send an offer to the signaling server that is then sent to all other connected peers? I am unsure whether this is the right approach.

Answer 1

If what you are trying to do is create a mesh network with audio and video flowing at all times to everyone via a mesh network then I'd suggest reconsidering. Getting this to more than 3 or 4 users to work well is hard to impossible to achieve. See here for an explanation of what goes on the network for different network topologies: http://testrtc.com/different-multiparty-video-conferencing/

If you are trying to do this to get data connected (non voice or video), then you can do that, but again, the number of peer connections you can place in a single browser is limited and each one you add puts some overhead. Today, I wouldn't try to get this over 40 or 50 at most.

By your question, I am assuming all clients will be connected to your server via a WebSocket. You will probably end up routing messages through the server and creating peer connections judiciously when you want to connect a specific user to another one - or a small group of users together.

For the group scenario, I'd use an SFU model - look at Jitsi (https://jitsi.org/Projects/JitsiVideobridge) and Kurento (http://www.kurento.org/) for possible alternatives.