Homework 3

Answer the following questions about Kurose and Ross, Chapter 3. You only need to turn in those that have a point count assigned.

1. What information is used for demultiplexing in TCP? In UDP?
2. (1 point) What is the purpose of acknowledgements in reliable data transfer protocols?
3. (1 point) Why are timers needed in realistic reliable data transfer protocols?
4. (1 point) What is the main advantage of pipelining/windowing in reliable data transfer protocols?
5. What is the primary disadvantage of the alternating bit reliable data transfer protocol?
6. (1 point) How do the Go-Back-N and Selective Repeat reliable data transfer protocols differ with regard to the following?
   1. Number of timers
   2. Handling a timeout
7. What is meant by piggybacked acknowledgements? What reliable data transfer protocol uses piggybacked acknowledgements?
8. (1 point) What is meant by cumulative acknowledgements? What reliable data transfer protocol uses cumulative acknowledgements?
9. In what ways does congestion make itself worse?
10. What is the primary drawback of doing congestion control in the transport layer?