Question $8$

$4$ pts

Browser Caching. Consider an HTTP server and client as shown in the figure below. Suppose that the RTT delay between the client and server is $20$ msecs; the time a server needs to transmit an object into its outgoing link is $0\mathrm{.}75$ msecs; and any other HTTP message not containing an object has a negligible $($zero$)$ transmission time. Suppose the client makes $40$ requests, one after the other, waiting for a reply to a request before sending the next request.

Assume the client is using HTTP $1\mathrm{.}1($persistent HTTP$)$ and the IF$-$MODIFIED$-$SINCE header line. Assume $80\%$ of the objects requested have NOT changed since the client downloaded them $($before these $40$ download requests are performed$).$

How much time elapses $($in milliseconds$)$ between the client transmitting the first request, and the completion of the last request $($ignoring TCP connection setup time$)?$