public UdpPinger( string machineName, int port, int timeoutMillis = 0 ) { if (timeoutMillis < 0) { throw new ArgumentOutOfRangeException( "timeoutMillis", "Timeout is less than zero." ); } this._timeout = timeoutMillis == 0 ? DefaultTimeout : timeoutMillis; this._machineName = machineName; this._port = port; this._pingHandler = PingPort; }