RTCMultiConnection.socketOptions
Socket.io protocol options

How to use

connection.socketOptions = {
    'force new connection': true, // For SocketIO version < 1.0
    'forceNew': true, // For SocketIO version >= 1.0
    'transport': 'polling' // fixing transport:unknown issues
};

Otherwise

connection.socketOptions.resource = 'custom';
connection.socketOptions.transport = 'polling';
connection.socketOptions['try multiple transports'] = false;
connection.socketOptions.secure = true;
connection.socketOptions.port = '9001';
connection.socketOptions['max reconnection attempts'] = 100;
// etc.