code: public void updateReturnTripTime () {
  		Ping ping = new Ping();
  		ping.id = lastPingID++;
  		lastPingSendTime = System.currentTimeMillis();
  		sendTCP(ping);
  	}
docs: Requests the connection to communicate with the remote computer to determine a new value for the
  {@link #getReturnTripTime() return trip time}. When the connection receives a {@link FrameworkMessage.Ping} object with
  {@link Ping#isReply isReply} set to true, the new return trip time is available.