CS536 Homework 4due Fri, Dec 4th, 10:30amNovember 24, 2009Submit your homework electronically in a text or PDF file to BlackBoard.No credit will be given for this assignment on the final grade. Late submissionwill not be accepted, nor will collaboration.Problem 1 (10 pts)End-to-End Argument. Consider the design of e-mail. Apply the principleof the end-to-end argument and evaluate whether e-mail reinforces or violatesit and why. Argue your conclusions for the first problem.Problem 2 (10 pts)Akamai. DNS is a major component of how Akamai works. In what ways doesAkamai’s implementation of DNS differ from the traditional implementation?Problem 3 (10 pts)Consider a short, 10-meter link, over which a sender can transmit at a rate of 120bits/sec in both directions. Suppose that packets containing data are 150,000bits long, and packets containing only control (e.g ACK or handshaking) are240 bits long. Assume that N parallel connections each get 1/N of the linkbandwidth. Now consider the HTTP protocol, and suppose that each down-loaded object is 120 Kbits long, and that the initial downloaded object contains10 referenced objects from the same sender. Would parallel downloads via par-allel instances of non-persistent HTTP make sense in this case? Now considerpersistent HTTP. Do you expect significant gains over the non-persistent case?Justify and explain your answer.Problem 4 (10 pts)Give two examples of why the address given in an “RCPT TO:” SMTP com-mand would differ from the “To:” field in the email body.1Problem 5 (20 pts)Consider distributing a file of F bits to N peers using a P2P architecture.Assume a fluid model. For simplicity assume that dminis very large, so thatpeer download bandwidth is never a bottleneck.a. Suppose that us≤ (us+ u1+ . . . + uN)/N. Specify a distribution schemethat has a distribution time of F/us.b. Suppose that us≥ (us+ u1+ . . . + uN)/N. Specify a distribution schemethat has a distribution time of NF/(us+ u1+ . . . + uN).c. Conclude that the minimum distribution time is in general given bymax{F/us, N F/(us+ u1+ . . . + uN)}.Problem 6 (20 pts)Define each of the following distinctions between application protocols, and givean example of opposing protocols:a. in-band vs. out-of-bandb. open vs. proprietaryc. text vs. binaryd. client-server vs. peer-to-peere. stateless vs. statefulf. push vs. pullProblem 7 (20 pts)Explain why Chord DHT lookups, while taking O(log N) hops, may traversethe globe multiple times. Describe how finger selection could be modified tohelp mitigate this