Since build 0.5.28.2753.125 it is possible to set Websocket connection establishing timeout while session creation. To do this, timeout  parameter in milliseconds should be passed to createSession function:

    var url = "wss://test.flashphoner.com:8443";
    var tm = 1000;

    Flashphoner.createSession({urlServer: url, timeout: tm}).on(SESSION_STATUS.ESTABLISHED, function (session) {
        ...
    });

In server does not respond in this time, client will receive the SESSION_STATUS.FAILED event.