COMPUTER SUBJECT: BASIC NETWORK CONCEPTS
TYPE: GROUP WORK EXERCISE/DISCUSSION
IDENTIFICATION: INTRODUCTION/MC
COPYRIGHT: Michael Claudius
LEVEL: EASY
DURATION: 1-4 hours
SIZE: 100 lines!!
OBJECTIVE: Introduction to network basic
REQUIREMENTS: Computer
Networks
COMMANDS:
IDENTIFICATION: Chapter2/MC
1. What is the difference between network
architecture and application architecture?
2. Describe the essence in a pure client-server network architecture.
3. What are the problems in a pure client-server ?
4. Describe the essence in a pure P2P application
architecture.
5. What are
the problems in a P2P architecture ?
6. What is a socket and what is it used for ?
7. Different applications have different requirements.
Discuss various applications needs for
reliability, bandwidth and timing
8. What is the meaning of the word bandwidth.?
Logically and concrete ?
9. Find 10 or more important design criteria for
computer networks.
Can you order them ?
10. Congratulations. You have succeeded with the chapter
2.1 J
IDENTIFICATION: Chapter2/MC
11. HTTP is a stateless, persistent connection,
with pipelining, pull protocol.
Now explain:
What does stateless mean and why is this smart
for http.
What is the difference between:
Serial
vs. parallel
Synchronous
vs. asynchronous
Persistent vs. non persistent
Without pipelining vs. with pipelining
Push vs. pull protocol
12. In a group you are to discuss what happens when
a browser/client request a page/file from a web-server. For example by
discussing the following questions:
What does the browser do ?
What does the client actually do ?
What does the client send with the GET-command
?
What does the server do when it receives the
request ?
What happens in the https-protocol layer ?
How does it find the correct file ?
What does the web-server send with the
OK-response ?
What does the client do with the response ?
What does the browser do with the response ?
13. Start an internet
browser, a packet-sniffer like Wireshark and then surf. Stop the sniffing..
Investigate a
http-request with the GET-command, i.e. explain some but not all of the fields
in the packet.
Investigate a
http-response with the OK-response, i.e. explain some but not all of the fields
in the packet.
14. Go to http://wps.pearsoned.com/ecs_kurose_compnetw_6/
run the exercise in Chapter 2
Explain what happened!
Tip: http://en.wikipedia.org/wiki/Push_technology; http://en.wikipedia.org/wiki/Http
15. What is “last-modified” field used
for ?
16. Go to networks tools http://network-tools.com
Run each of the various tools.
Look up unknown words in: http://en.wikipedia.org/wiki/Firewall
17. Congratulations. You have succeeded with the
chapter 2.2. J
18. DNS stands for what ?
19. Why is DNS not built upon a centralized
architecture ?
20. Which services are provided by DNS ?
21. Elaborate over the word canonical ?
22. DNS is a 3 level hierarchy. What is the
responsibility of each level ?
23. What is the difference between recursive and
iterative request ?
Go to http://wps.pearsoned.com/ecs_kurose_compnetw_6/
run the exercise in Chapter 2.5
Explain what happened!
24. Congratulations. You have succeeded with the
chapter 2.5 J
25. P2P stands for what ?
26. State the 3 different types of P2P structures
27. BitTorrent file distribution
How is a file distributed ?
How can a peer join the torrent ?
What shall a peer request first ? and why ?
To whom shall a new peer send chunks ?
28. Explain the distributed structure.
How is query handled?
How is a join handled?
How is a departure handled?
29. What is the problem with query flooding?
30. What is the problem with limited query
flooding?
31. Explain the hierarchical structure.
How is query handled?
How is a join handled?
How is a departure handled?
32. Skype was originally designed as a hierarchical
distributed system.
Describe the structure by answering the
following overlapping questions:
What was the role of super peers in Skype ?
What were relay peers used for and why ?
How is a Skype call established and why ?
33. In 2011 Microsoft bought Skype for the second
time and later changed the structure.
Which structure is now in use?
Point out some advantages/disadvantages?
Can you find a reason for the new structure?
34. Congratulations. You have succeeded with the
chapter 2.6 J
35. Explain the three way handshake for
establishing a TCP-connection.
36. Look at the two programs TCPClient and
TCPServer.
Go through each of the programs and line by
line explain what goes on.
37. Solve the special exercise on socket handed out
by the teacher.
38. Congratulations. You have succeeded with the
chapter 2.7 J
39. Look at the program WebServer
Go through the programs and line by line
explain what goes on.
40. Solve the special exercise on socket handed out
by the teacher.
41. Congratulations. You have succeeded with the
chapter 2.5 J