SOURCE

var connection = new RTCMultiConnection();
connection.socketURL = 'https://rtcmulticonnection.herokuapp.com:443/';
connection.socketMessageEvent = 'textchat-plus-fileshare-demo';
connection.session = {
                data: true
            };
 connection.sdpConstraints.mandatory = {
                OfferToReceiveAudio: false,
                OfferToReceiveVideo: false
            };
connection.onmessage =