example-RTC.js

var signalingChannel = new SignalingChannel(); 
var pc = new RTCPeerConnection({}); 

navigator.getUserMedia({ "audio": true }, gotStream, logError);  

function gotStream(stream) {
  pc.addStream(stream); 

  pc.createOffer(function(offer) { 
    pc.setLocalDescription(offer); 
    signalingChannel.send(offer.sdp); 
  });
}

function logError() { ... }