code: public void udpPacketReceived(String sender, String host, int port) {
  
  		// Debug
  		if (debugHeartbeats) {
  			logger.info("Discovery message received from \"" + sender + "\" node (host: " + host + ", port: " + port
  					+ ").");
  		}
  
  		// Register as offline node (if unknown)
  		registerAsNewNode(sender, host, port);
  	}
docs: --- UDP MULTICAST MESSAGE RECEIVED ---