{HEAD ~ The method} comprises maintaining at least one connection to the server, receiving requests from the clients, transmitting {TAIL ~ the requests} to the server, receiving responses to the requests from the server, and monitoring a server response time for a selected request sent to the server, the server response time for the selected request being the time elapsed between transmitting the selected request to the server and receiving a corresponding response from the server 
comprises transmitting
{ HEAD ~ The method } comprises maintaining at least one connection to the server , receiving requests from the clients , transmitting { TAIL ~ the requests } to the server , receiving responses to the requests from the server , and monitoring a server response time for a selected request sent to the server , the server response time for the selected request being the time elapsed between transmitting the selected request to the server and receiving a corresponding response from the server
HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH