Doubts in no particular order:

1. Fall 2005 Question 1 b) In the deep slumber of the night, the ghost of Albert Einstein comes to you, exhorting you to not take the end-to-end principle on faith, but to realize that it can be justified based on probabilistic analysis. That is, a given probability of undetected failure can be achieved at a lower cost using an end-to-end design rather than the alternative(s?). Give an example of a.simple end-to-end design and probalistic analysis that supports Albert's position, or else argue that this is nonsense (perhaps induced by Albert's discomfort with entanglement).

2. Fall 2004 Question 2 a) Joe Conservative claims that TCP works well for his applications over the WAN but is inefficient for his LAN applications. Bill Liberal claims that TCP works for his applications over the LAN but is inefficientfor his WAN applications. Describe how they can both be right, tying your answer to specific aspects of the TCP design.

3. The exact reason behing the LAST_ACK and TIMED_WAIT states in the TCP state machine.

4. Fall 2002 Question 2 b) Provide a formula for determining the TCP maximum throughput for a given packet drop rate D, introducing whatever additional parameters/variables you need, e.g. max link data rate R, MTU M, etc. and assuming that only data packets are dropped, there is at most one drop occurring per go-back-N event, and the transmission rate in the absence of drop is only limited by the link rate.

5. Why is TCP's protocol number 6. In the slides, the professors mention that this is low. What's the reason why TCP has a low number?

6. Fall 2006 Q2. Elasticity Buffer. An elasticity buffer is used to store bits arriving at a network interface. If the receiving station uses a 200-bit elasticity buffer and the clocks of the transmitter and receiver have a minimum frequency of 99.999MHz and a maximum frequency of 100.001MHz, which of the following statements are true:

(a.) All packets have to be less than or equal to 12,500 bytes long.

(b.) All packets have to be less than or equal to 4500 bytes long.

(c.) The two clocks have a tolerance of +/- 100ppm.

(d.) The two clocks have a tolerance of +/- 10ppm.

(e.) The transmitter’s clock is always faster than the receiver’s clock.

7. Why are there "spanning tree loops"? How do they occur, and how are they sorted out?

8. What is the concept behind the destination sequence number in ad-hoc distance vector routing algorithms in Wireless networks.