CSCI 547                                Midterm Exam                       Fall 2007

Closed Book, Closed Notes, Do not write on the back of pages!

                                                                        Name: ______________________________

Q1(2  points): What is ARPANET?

Q2(4 points): List(at least 4) the kinds of information stored in Internet RFCs.

Q3(3 points): OSI protocols are not popularly implemented but OSI model is still important. Why?

Q4(1 points): Give an example of SAP(Service Access Point)

Q5(2 points): Which organization, under ISOC(Internet Society), is responsible for the Internet Standards?

Q6(4 points): Describe the difference between gTLD and ccTLD.

Q7(1 points): How many root DNS domains exist today?

Q8(6 points): Describe the difference between “iterative queries” and “recursive queries”

Q9(6 points): Point out the differences between “persistent http” and “non-persistent http”.

Q10(4 points): Point out the difference(s) between “persistent http without pipelining” and “persistent http with pipelining”.

Q11(4 points): When we need to input some information in an http session, there are two ways to do that; Post method and URL method. Explain how the “URL method” works.

Q12(6  Points): List three cases where “cookies” can be used.

Q13(12  points):

a) In TCP/IP protocol suite, some protocols are stateful and some are stateless. Two examples of stateless protocols are 1) __________ 2) _________. Stateless protocols’ main advantage is ___________________________

b) Two examples of stateful protocols are 1) __________ 2)____________. Stateful protocols’ main advantage is ________________________

Q14(4  Points): Using TCP, we make a connection with socket to socket connection. What are the 4 tuples that make any socket connection unique?

Q15(6  points): Describe how an e-mail system finds the IP address of an e-mail server. In other words, when we send an e-mail to john@somewhere.com, how your e-mail server finds the IP address of the mail server at “somewhere.com” without knowing the server’s name(for example, mail.somewhere.com).

Q16(4 points): What is MIME(Multipurpose Internet Mail Extensions)?

Q17(4 points): As an application developer, when would you choose UDP over TCP?

Q18(3 points): What are the 3 phases a “connection-oriented protocol” must go through?

Q19(3 points): What are “Ephemeral ports” in TCP or UDP?

Q20(6  points): Describe the two reasons why TCP needs 3-way handshake for connection establishments.

Q21(4 points): We discussed that QOS(Quality of Service) can be easily accommodated if a network or link layer service such as ATM provides connection oriented service. Discuss how?

Q22(5 points): Describe how TCP adjusts the RTT(Round Trip Time). Exact formula is not necessary.

Q23(8  points) TCP’s congestion control:

a) Describe the difference between Tahoe and Reno versions of TCP congestion control.

b) Describe TCP’s “Slow Start”.