Figure 2.4, “WebRTC basic peer-to-peer” demonstrates how two browsers can communicate with each other using WebRTC. The web browsers start by downloading the HTML, CSS and JavaScript from a normal web server such as Apache httpd. The JavaScript uses the WebSocket protocol to initiate a connection to the SIP proxy. When a call is made, the request is sent over the WebSocket connection and the media streams pass through the TURN server. In this case, the browsers are not relaying the media streams through the TURN server, possibly because they have discovered they are both on the same IP network.