$HTTP$ Performance. Consider the scenario shown below, $in$ which $HTTP$ servers reside $in$ the upper network, and $HTTP$ clients $(browsers)$ reside $in$ the lower network. Each server connects $to$ the upper router via a link $of$ capacity $Rs$; each client connects $to$ the lower router via a link $of$ capacity $Rc.$ The two routers connect $to$ each other via a link $of$ capacity $RI.$

Suppose $anHTTP$ client makes a request $to$ a web server $(say$ the leftmost webserver$).$ The client has never before communicated with this server. You can assume, however, that the client host knows the $IP$ address $of$ the server.

How many round trip times $(RTTs)$ are needed from when the client first makes the request $to$ when the base page $is$ completely downloaded, assuming the time needed $by$ the server $to$ transmit the base file into the server's link $is$ equal $to\frac{1}{4}RTT$ and that the time needed $to$ transmit the $HTTP$ GET into the client's link $is$ zero? $(You$ should take into account any $TCP$ setup time required before the $HTTP$ GET $is$ actually sent $by$ the client, the time needed for the server $to$ transmit the requested object, and any propagation delays included $in$ the $RTT.)$