CS158a Spring 2023 Practice Final

If you did well on the midterm, the same approach to studying should work for the final. If not, if adjust the amount of studying you do for the final and experiment with how the way you are studying helps you remember the material and how it affects your ability to use the material flexibly.

Here are some facts about the actual final:

1. It is comprehensive covering all the material of the semester.
2. It is closed book, closed notes. Nothing will be permitted on your desk except your pen (pencil) and test.
3. You should bring photo ID.
4. There will be more than one version of the test. Each version will be of comparable difficulty.
5. It is 10 problems, 6 problems will be on material since the midterm, four problems will come from the topics covered prior to the midterm.
6. Two problems will be exactly (less typos) off of the practice final, and one will be off of practice midterm.

The practice final is below:

1. Briefly describe the three-way handshake mechanism for establishing a TCP connection. What happens if the client's final ACK is lost? What is the usual sequence of messages to close a connection?
2. In TCP, how is the AdvertisedWindow calculated? How is EffectiveWindow calculated? Give an example using concrete sender and receiver queues of how one might end up with an AdvertisedWindow of 50 and an EffectiveWindow of 0 bytes. What does a sender do if the EffectiveWindow size stays at 0?
3. Briefly explain each of the following: (a) Nagle's Algorithm, (b) Karn/Partridge Algorithm, (c) Jacobson/Karels Algorithm.
4. Describe how QUIC differs from TCP with regard to: (a) connection set-up, (b) wireless traffic, (c) head-of-line blocking.
5. For each of the following RPC protocols say (a) one common place it is used, (b) how remote procedures are identified, (c) if it can be implemented over TCP or UDP or both: (i) SUN-RPC, (ii) DCE-RPC, (iii) gRPC.
6. Suppose a network has a 100mS delay and has five flows of 1Mbps, 2Mbps, ... , 5Mbps. What is the power of this network? What is its fairness? Briefly explain how CongestionWindow affects EffectiveWindow size (give formula) and how AIMD works.
7. Give the formulas for how RED determines if a packet will be dropped together with a concrete example. What is RIO? Where is RIO used on the internet?
8. Briefly explain the parameters used to specify a flowspec if IntServ QoS is being used. Briefly explain how RSVP PATH and RESV messages are used.
9. Give a short overview of each of the following presentation layer formats: (a) ASN.1, (b) GIF file format.
10. Give an example session where a user telnets into a POP3 server and retrieves a list of their main messages.