This is the simpliest example of an app that uses WebRTC to send video I could made. I followed some tutorials I found on the Internet, specially this series of posts and Google's official Codelab.
I wrote a brief post on the issue that you can check out here.
I'm using WebSocket protocol to communicate with the server.
First install the Web Socket module
npm install websocket
Having the module install, you only need to have nodeJS installed in your computer to run the server part that will work as signaling service. To start the server just type the following command
node index.js