WebRTC signaling refers to the process of setting up, controlling, and terminating a communication session. In order for two endpoints to begin talking to one another, three types of information must be exchanged: Session control information determines when to initialize, close, and modify communications sessions.
For details please visit https://www.html5rocks.com/en/tutorials/webrtc/basics/
We do offer free Signaling Server, for the basic & non-commercial use only, to jumpstart the application. Eventually you will have to get your own Signaling Server, either by setting up your own or purchasing the service from third party service provider.