WebRTC：确定所选的ICE候选者

Question

I have a webrtc app, and let's say two clients( client1 and client2 ), is there any way to find out what ICE candidate given by client1 is used by client2 and vice versa? because, every time to find this out, I have to use wireshark on both the clients, I thought reading the sdp might help, but I was wrong, as it gives all possible candidates...

Scenario: all UDP ports of client1 are blocked( blocked my me for testing purpose).
Client1's SDP:

...
a=rtcp:49407 IN IP4 <client1's IP>
a=candidate:3864409487 1 udp 2122194687 <client1's IP> 49407 typ host generation 0 // this would never work, since the udp ports are blocked...
a=candidate:3864409487 2 udp 2122194687 <client1's IP> 49407 typ host generation 0
a=candidate:2832583039 1 tcp 1518214911 <client1's IP> 0 typ host tcptype active generation 0
a=candidate:2832583039 2 tcp 1518214911 <client1's IP> 0 typ host tcptype active generation 0
a=candidate:973648460 1 udp 25042687 <TURN server IP> 64790 typ relay raddr <Proxy IP> rport 39963 generation 0
a=ice-ufrag:YSvrOiav8TglpCWD
...

Answer 1

Well, taken from my answer to another question

I wrote and tested the below piece of code, works in latest versions of both firefox and chrome, getConnectionDetails returns a promise which resolves to connection details:

function getConnectionDetails(peerConnection){


  var connectionDetails = {};   // the final result object.

  if(window.chrome){  // checking if chrome

    var reqFields = [   'googLocalAddress',
                        'googLocalCandidateType',   
                        'googRemoteAddress',
                        'googRemoteCandidateType'
                    ];
    return new Promise(function(resolve, reject){
      peerConnection.getStats(function(stats){
        var filtered = stats.result().filter(function(e){return e.id.indexOf('Conn-audio')==0 && e.stat('googActiveConnection')=='true'})[0];
        if(!filtered) return reject('Something is wrong...');
        reqFields.forEach(function(e){connectionDetails[e.replace('goog', '')] = filtered.stat(e)});
        resolve(connectionDetails);
      });
    });

  }else{  // assuming it is firefox
    return peerConnection.getStats(null).then(function(stats){
        var selectedCandidatePair = stats[Object.keys(stats).filter(function(key){return stats[key].selected})[0]]
          , localICE = stats[selectedCandidatePair.localCandidateId]
          , remoteICE = stats[selectedCandidatePair.remoteCandidateId];
        connectionDetails.LocalAddress = [localICE.ipAddress, localICE.portNumber].join(':');
        connectionDetails.RemoteAddress = [remoteICE.ipAddress, remoteICE.portNumber].join(':');
        connectionDetails.LocalCandidateType = localICE.candidateType;
        connectionDetails.RemoteCandidateType = remoteICE.candidateType;
        return connectionDetails;
    });

  }
}


//usage example:
getConnectionDetails(pc).then(console.log.bind(console));