{TAIL ~ Proxy server} 105 may aggregate and store performance data provided by {HEAD ~ control units} 150 and 165, respectively 
{ TAIL ~ Proxy server } 105 may aggregate and store performance data provided by { HEAD ~ control units } 150 and 165 , respectively
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH