protected void beat(){
  sendUDPString(getBeatSignal(),this.address,this.port);
  this.timeOfLastBeat=System.currentTimeMillis();
}

protected void beat ( ) { sendUDPString ( getBeatSignal ( ) , this . address , this . port ) ; this . timeOfLastBeat = System . currentTimeMillis ( ) ; }
send a simple beat signal via udp .
