The connections between {HEAD ~ connection management device} 20 and server 14 are typically {TAIL ~ persistent connections} 
The connections between { HEAD ~ connection management device } 20 and server 14 are typically { TAIL ~ persistent connections }
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL