INT21CN Computer Networks

Tutorial #2

1. What is a protocol? How does the use of the word "protocol" in computer networking differ from its meaning in other contexts?

2. What is the origin of the term Internet?

3. The Internet Protocol IP is described as a "hop-by-hop" protocol, in contrast to TCP, which is an "end-to-end" protocol. Discuss briefly the meaning of these terms, mentioning the role of both routers and edge systems.

4. What are the three key characteristics of unreliable IP packet delivery in the Internet?

5. If the Internet is unreliable, how can it possibly be used to transfer important data? Discuss this, and be sure you understand the answer!

6. What tasks are performed by the TCP transport service (or layer)? Name two.

7. In the example from the lecture, the TCP layer (or module) split the application data unit into two segments. Give reasons why it might do this.

8. Why is it impossible for TCP to make any guarantees about how long data may take to be delivered?

9. In TCP, what term is given to an application process which accepts incoming connections? What about a process which initiates connections?

10. Explain briefly the need for port numbers in the establishment of TCP connections.

11. In a "layered network architecture" (or "protocol stack"), what is meant by "peer-to-peer" communications?

12. When manually configuring a desktop computer system for connection to the Internet, one of the parameters which must (usually) be set (for MS-Windoze) is the Gateway (or Default Gateway). What is the purpose of this parameter?

13. Many aspects of the Internet are strongly reminiscent of Unix. In the URL given as an example in the lecture, what aspects are similar to "the way things are done in Unix"?

14. Philosphical question: the Internet moves complexity to the edges of the network. How does this compare to, for example, the telephone system?