How to begin gathering ICE candidates for peer connection

Question

I am developing the signaling system between two peers and have noticed that the RTCPeerConnection.onicecandidate event is not firing. I checked the iceGatheringState and it always returns as "new" meaning the peer connection has not began searching for ice candidates.

How do I initiate the gathering of ice candidate objects from the local machine to be sent out to a peer?

and

If I do not want to trickle candidates, how will I be able to send them over sdp once gathered?

This is my current code, I am able to successfully attain sdp data and capture them to be sent so ice and checking if the two clients are connected are the only issues.

var peerConn = new webkitRTCPeerConnection(
    {'iceServers':[{'url':'stun:stun.1.google.com:19302'}]}
);
var remoteConn = new webkitRTCPeerConnection(
    {'iceServers':[{'url':'stun:stun.1.google.com:19302'}]}
);

alert(peerConn.iceGatheringState);

///Event Handlers//
//will be called when each event occurs

//onicecandidate
//returns local ice candidates (when gathered) to be sent to peer
//peerConn.onicecandidate = onicecandidate;
peerConn.onicecandidate = function(iceEvent){ //not firing
    if(iceEvent.candidate === null){
        alert(peerConn.iceConnectionState);
        alert(iceEvent.candidate);

        //send to peer or put in with sdp data
    }
}

Philipp Hancke Philipp Hancke · Accepted Answer · 2016-07-22T18:42:23

ICE gathering starts once you call setLocalDescription with the SDP you generated with createOffer or createAnswer.

If you don't want to use trickle ice, wait for the null candidate and then send the content of peerConn.localDescription.sdp -- which should include the candidates then.

How to begin gathering ICE candidates for peer connection

1 Answers