A campus network is connected to the Internet via an access link with 100 Mb/s upload rate and practically unlimited download rate. Sixty percent of the access link bandwidth is used to access the Internet and browse Web pages by the users of the campus network; 30% of the bandwidth is used for other work: to communicate with other business entities and to update/retrieve proprietary data. For the sake of simplicity, assume that each transmission (of a web object or productive data) to the Internet takes an average of 10 ms over the access link. Delays incurred in the Institutional network and the Internet on the other side of the access link are ignored.

(a) What is the delay for the communication used for productive work?

(b) What is the average queue length (the number of web objects and/or proprietary data transmissions) for the access link?

(c) Suppose a web cache is used to cache web pages and Web cache hit rate is 0.4. Will the response time of the communication used for other work (which is not cached) be improved? If your answer is yes, by how much? If your answer is no, justify.