Reference no: EM132411319

Assignment - Application Layer

Review questions -

1. What are the functions of the application layer? How were the earliest application-layer protocols defined? What application do you spend the most time on?

2. How has the web been most useful to you?

3. What are the three most popular websites in the world today? What primary service does each site offer?

4. Describe some changes in the patterns of Internet usage based on changes in the list of most popular websites globally.

5. Why is the web gaining popularity as a marketing tool over traditional methods such as yellow pages?

6. What is a hyperlink?

7. What is an inlink? What information about a web page can be inferred from inlinks to the page?

8. What is HTML?

9. Provide an overview of the structure of a web page.

10. What is URL? Describe the parts of a typical web URL.

11. What is a killer application?

12. In what ways do you use e-mail in your daily life? When do you prefer to use e-mail over the postal system? When do you prefer the postal system over e-mail?

13. Describe the differences between pull and push forms of communication, using the web and e-mail as examples.

14. Using examples from your own life, describe some advantages of e-mail as a communication medium compared to your other choices (such as cell phones, meetings).

15. What are some potential disadvantages with e-mail as a communication medium? Can you describe some occasions when you have run into these disadvantages of e-mail?

16. What is flaming?

17. Describe the high-level structure of the e-mail system.

18. What are an MTA and an MUA in the context of e-mail?

19. What is the role of SMTP in e-mail?

20. What is the role of POP/ IMAP in e-mail?

21. What are some important differences between POP and IMAP?

22. What is FTP?

23. How is FTP different from HTTP?

24. What is instant messaging? How is IM different from e-mail?

25. What is presence in the context of IM?

Hands-on exercise -

1. Using online and any other resources, write a brief summary of how Wireshark is used to manage computer networks.

2. What are the sequence and acknowledgement numbers of the three TCP packets performing the three-way handshake? These packets were exchanged just before the GET request for the web page.

3. Right-click an HTTP packet and select "Follow TCP stream." What are the HTTP header fields in the first client request and the first server response? What are the values in these fields?

3. How many different GET requests did your browser have to make to download the entire page? What were the arguments to these GET requests? For example, as shown, the browser made two GET requests. The first request asked for "/html101.html" and the second GET request asked for "/favicon.ico." If there are more than five GET requests, only list the arguments for the first five GET requests. (A very convenient way to do this is to first select "Follow TCP stream" and then sort the results by the Info column. All the GET packets will be collected together.)

4. What is the IP address of your default gateway? This is obtained from ipconfig.

5. What is the MAC address (physical address) of the default gateway identified above? This is obtained from arp -a.

6. Select an HTTP packet. List its source and destination IP addresses as well as source and destination Ethernet addresses.

7. Referring to the figure and the information collected in questions 4 and 5 above, what machines does each of these addresses (MAC and IP) refer to? You may be able to relate this to the idea that whereas MAC addresses are hop-by-hop addresses, IP addresses are end-to-end addresses.

8. What are the source and destination port addresses in the selected packet?

9. Look up your etc\services file (In Windows, this file is usually located in C:\Windows\System32\drivers\etc). Which of these ports is a standard port? Paste the entire line from the etc\services file that contains information about this port.

Critical thinking exercise -

1. What were the provisions of SOPA?

2. What was the motivation for SOPA?

3. What were the concerns of the protestors?

4. Who do you agree with -the lawmakers who drafted the act, or the protestors?

5. Under what conditions would you support laws such as SOPA?

IT infrastructure design exercise -

1. For at least five of these uses of computer networking, use the Internet or other sources to identify the market-leading software applications used to obtain the required functionality (for example, to serve web pages, the market-leading software is the Apache web server). In a table, provide the following information for the five uses: the application (use) category, the market-leading software application in the category, and a paragraph or two about the strengths of the selected software application. (You can use the marketing information from the application's website to describe the strengths of the application.)

Example case questions -

1. How do you use Google for advertising?

2. What are some emerging trends in digital marketing?

3. How can your university use digital marketing to improve student placement?

4. Take a leading national newspaper or your leading local newspaper. Briefly describe its online presence. Include information such as the following: What are the major news categories on the publication's website? What are the main products or services advertised? What customization options does the site offer? Does it charge a subscription fee for online content? What do you think is the newspaper's target audience?