var init_ext = function() {

    Client.destroy_all();
    if (http_ext) {
        http_ext.close(function() {
            my.log('ext server closed');
        });
    }

    http_ext = net.createServer(function(c) { //'connection' listener

        var auth_buffer = new Buffer(0);
        var auth_obj = null;
        var client = null;

        my.log('server connected', auth_obj);

        c.on('data', function(d) {
            my.log("ctl", "conn", "read", d.length);

            if (!auth_obj) {
                auth_buffer = Buffer.concat([auth_buffer, d]);
                auth_obj = pir.unpack(auth_buffer).obj;
                if (auth_obj && auth_obj.type == "auth_obj") {
                      client = Client.get_client(auth_obj);
                      if (!client.int_conn) {
                          client.set_int_conn(c);
                      }
                      my.log("client", "auth", client.auth_obj);
                }
            }
            if (auth_obj) {
                //other code here
            }
        });

    });
    http_ext.listen(config.ext_connectback_port, config.ext_connectback_host, function() { //'listening' listener
        my.log('ext server bound', config.ext_connectback_port, config.ext_connectback_host);
    });

}