HTTP Performance: access link utilization.

Now suppose that a web cache is added the lower network, as shown in the figure below, but that in all other aspects the network below is the same as the network above. All HTTP requests are first directed to the local web cache. You can assume that the delays $($both propagation delays and any transmission delays between the cache and a client are zero, since both are resident in the same network$).$ The client's browser cache is empty.

Suppose that an HTTP client makes a request to a web server and that the request object is found in the cache $($a cache $\backslash "$hit$\backslash ")$ and known to be upfto$-$date in the local cache. There are no embedded object in the requested page. How many round trip times $($RTTS$)$ are needed from when the client first makes the request to when the base page is completely downloaded.

Suppose that:

The capacity of the link connecting the upper and lower networks is $R_1=$ bits per second$)$

The link capacities $R_C$ and $R_S$ are so large that they are never a bottleneck and can be ignored.

Each object requested by a client is $1$ Mbits bits$)$ in size Each of four clients is individually making HTTP GET requests at a rate of $10$ requests per second.