Consider Figure $2\mathrm{.}12,$ for which there is an institutional network connected to the Internet. Suppose that

the average object size is $1,000,000$ bits and that the average request rate from the institution's browsers

to the origin servers is $14$ requests per second. Also suppose that the amount of time it takes from when

the router on the Internet side of the access link forwards an HTTP request until it receives the response is

three seconds on average $($see Section $2\mathrm{.}2\mathrm{.}5).$ Model the total average response time as the sum of the

average access delay $($that is$,$ the delay from Internet router to institution router$)$ and the average Internet

delay. For the average access delay, use $\frac{}{1-},$ where $$ is the average time required to send an object

over the access link and $$ is the arrival rate of objects to the access link.

a$.$ Find the total average response time.

b$.$ Now suppose a cache is installed in the institutional LAN. Suppose the miss rate is $0\mathrm{.}4.$ Find the total

response time.