1. Consider the following institutional network system. Suppose the average object size is 100k bits and the average rate from browsers to origin servers is 15 requests/sec. (ignore the LAN delay in the following questions)

Assume that _access = 1.5 Mbps and the RTT on the Internet side of the access link is 2 sec.

a. Considering the queueing delay in the access router, the access delay could be calculated with the equation _access = (R_trans/1-traffic intensity) * R_trans represents the transmission delay at the access link. Without web cache, what is the total average response time?

b. Compare this result with the situation where access = 100 Mbps.

c. Suppose the local web cache satisfy 60% of the requests, the remaining 40% requests will be satisfied by the origin web servers. What is the total response time in this case?