Simple RTCDataChannel setup

rtc.js

var RTCPeerConnection = window.mozRTCPeerConnection || window.webkitRTCPeerConnection || window.RTCPeerConnection;
var RTCSessionDescription = window.mozRTCSessionDescription || window.webkitRTCSessionDescription || window.RTCSessionDescription;
var RTCIceCandidate = window.mozRTCIceCandidate || window.webkitRTCIceCandidate || window.RTCIceCandidate;
var RTC_CONFIGURATION = {"iceServers": [{"url": "stun:stun.l.google.com:19302"}]};
var MEDIA_CONSTRAINTS = {optional: [{internalSctpDataChannels: true},{DtlsSrtpKeyAgreement: true}]};

function errorCallback(error) {
    console.log(error);
}

var rtc1 = new RTCPeerConnection(RTC_CONFIGURATION, MEDIA_CONSTRAINTS);
var rtc2 = new RTCPeerConnection(RTC_CONFIGURATION, MEDIA_CONSTRAINTS);

rtc1.onicecandidate = function(e) {
    if (!e.candidate) return;
    console.log('candidate1');
    rtc2.addIceCandidate(e.candidate);
};
rtc2.onicecandidate = function(e) {
    console.log(e.candidate);
    if (!e.candidate) return;
    console.log('candidate2');
    rtc1.addIceCandidate(e.candidate);
};

rtc1.onnegotiationneeded = function() {
    console.log('onnegotiationneeded');
    rtc1.createOffer(function(desc1) {
        console.log('created desc1');
        rtc1.setLocalDescription(desc1, function() {
            console.log('set rtc1.local');
            rtc2.setRemoteDescription(desc1, function() {
                console.log('set rtc2.remote');
                rtc2.createAnswer(function(desc2) {
                    console.log('created desc2');
                    rtc2.setLocalDescription(desc2, function() {
                        console.log('set rtc2,local');
                        rtc1.setRemoteDescription(desc2, function() {
                            console.log('set rtc1.remote');
                        }, errorCallback);
                    });
                }, errorCallback);
            }, errorCallback);
        }, errorCallback);
    }, errorCallback);
};

rtc2.ondatachannel = function(e) {
    var dc2 = e.channel;
    window.dc2 = dc2;
    dc2.onerror = errorCallback;
    console.log('rtc2 received datachannel');
    dc2.onopen = function() {
        console.log('open2');
    };
    dc2.onmessage = function(e) {
        console.log(e);
    };
};

var dc1 = rtc1.createDataChannel('data');
dc1.onerror = errorCallback;

dc1.onopen = function() {
    console.log('open1');
    dc1.send('hi');
};

window.rtc1 = rtc1; window.rtc2 = rtc2; window.dc1 = dc1;