LTE-to-WIFI连接不适用于WebRTC连接,但WIFI-to-WIFI连接适用

我正在编写一个视频聊天应用程序,目前正在使用googles public STUN服务器,并向xirsys端点请求远程TURN服务器。当我查看日志时,我注意到使用LTE连接的设备正在发送bag tcp数据包,使用WiFi连接的设备正在发送udp数据包。起初,我认为问题是我只使用了STUN服务器,而不是TURN和STUN服务器。然而,我仍在获取数据。sdp未定义和/或icestateconnection卡在检查状态。请有人不仅回顾和分析代码及其谬误,而且解释为什么会发生这种情况,并提供您所知道的任何资源来帮助我理解这个问题。谢谢

[代码]

//fetch for ice servers
if (servers) {
  console.log(`servers: ${JSON.stringify(servers.v.iceServers, null, 2)}`);
  iceServers = [
    ...servers.v.iceServers,
    {"url": "stun:stun.l.google.com:19302"},
    {"url":'stun:stun1.l.google.com:19302'},
    {"url":'stun:stun2.l.google.com:19302'},
    {"url":'stun:stun3.l.google.com:19302'},
    {"url":'stun:stun4.l.google.com:19302'},
  ];
  return;
}

//configuration
pc = new RTCPeerConnection({"iceServers": iceServers};);

//exchange to signaling server
exchange(data) {
const fromId = data.from;

if (!pc)
  this.createPC(fromId, false);

console.log(`Data: ${JSON.stringify(data, null, 2)}`);
console.log(`Data.sdp ${data.sdp}`);
if (data.sdp) {
  console.log('exchange sdp', data.sdp);
  pc.setRemoteDescription(new RTCSessionDescription(data.sdp), function () {
    if (pc.remoteDescription.type === "offer")
      pc.createAnswer(function(desc) {
        console.log('createAnswer', desc);
        pc.setLocalDescription(desc, function () {
          console.log('setLocalDescription', pc.localDescription);
          socket.emit('exchange', {'to': fromId, 'sdp': pc.localDescription });
        }, logError);
      }, logError);
  }, logError);
} else {
  console.log('exchange candidate', data);
  pc.addIceCandidate(new RTCIceCandidate(data.candidate));
}

}