public TcpClientTransportSink(string url)
        {
            string objectUri;
            string port;

            TcpChannel.ParseTcpURL(url, out _host, out port, out objectUri);

            try {
                if (port != null)
                {
                    _port = Convert.ToInt32(port);
                }
                else
                {
                    _port = 0;
                }
            } catch {
                _host = null;
                _port = -1;
            }
        }