The server we are going to build in this chapter will help us connect two users together who are not located on the same computer. The goal of the server is to replace the signaling mechanism with something that travels over a network. The server will be straightforward and simple, supporting only the most basic WebRTC connections.

Our implementation will have to respond to and answer requests from multiple users. It will do this by having a simple bidirectional messaging system between clients. It will allow one user to call another and setup a WebRTC connection between them. Once a user has called another, the server will pass the offer, answer, and ICE candidates between the two users. This will allow them to successfully setup a WebRTC connection.

The preceding diagram shows the messaging flow between clients when using the signaling server to setup a connection. Each side will start by registering themselves with the server. Our logging in will simply send...