，参考

  var configuration = {
                    iceServers: [
                        // {urls: 'stun:stun.xten.com'},
                        { urls: 'turn:www.2edge.cn:3874','username': 'jiexun', 'credential': 'jiexun' }
                    ]
                };


iceServers.add(new PeerConnection.IceServer("stun:stun.l.google.com:19302"));
    iceServers.add(new PeerConnection.IceServer("stun:stun.services.mozilla.com"));
    iceServers.add(new PeerConnection.IceServer("turn:turn.bistri.com:80", "homeo", "homeo"));
    iceServers.add(new PeerConnection.IceServer("turn:turn.anyfirewall.com:443?transport=tcp", "webrtc", "webrtc"));

    // Extra Defaults - 19 STUN servers + 4 initial = 23 severs (+2 padding) = Array cap 25
    iceServers.add(new PeerConnection.IceServer("stun:stun1.l.google.com:19302"));
    iceServers.add(new PeerConnection.IceServer("stun:stun2.l.google.com:19302"));
    iceServers.add(new PeerConnection.IceServer("stun:stun3.l.google.com:19302"));
    iceServers.add(new PeerConnection.IceServer("stun:stun4.l.google.com:19302"));
    iceServers.add(new PeerConnection.IceServer("stun:23.21.150.121"));
    iceServers.add(new PeerConnection.IceServer("stun:stun01.sipphone.com"));
    iceServers.add(new PeerConnection.IceServer("stun:stun.ekiga.net"));
    iceServers.add(new PeerConnection.IceServer("stun:stun.fwdnet.net"));
    iceServers.add(new PeerConnection.IceServer("stun:stun.ideasip.com"));
    iceServers.add(new PeerConnection.IceServer("stun:stun.iptel.org"));
    iceServers.add(new PeerConnection.IceServer("stun:stun.rixtelecom.se"));
    iceServers.add(new PeerConnection.IceServer("stun:stun.schlund.de"));
    iceServers.add(new PeerConnection.IceServer("stun:stunserver.org"));
    iceServers.add(new PeerConnection.IceServer("stun:stun.softjoys.com"));
    iceServers.add(new PeerConnection.IceServer("stun:stun.voiparound.com"));
    iceServers.add(new PeerConnection.IceServer("stun:stun.voipbuster.com"));
    iceServers.add(new PeerConnection.IceServer("stun:stun.voipstunt.com"));
    iceServers.add(new PeerConnection.IceServer("stun:stun.voxgratia.org"));