INSTRUCTIONS

This lab has three parts.

Part I does NOT require you to submit anything. It contains questions which should help you think about the internet tools you are using, but you don't have to turn in answers to those questions. However, thinking about the questions should help you do part II.

Parts II and III contain questions where you need to save your answers in a file. If you don't have time to finish them all during the lab, then you can do the rest for homework. The answers are due AT THE BEGINNING OF CLASS on Wednesday September 20. Please bring a hardcopy (print out) to class.

Note that part III does not need to be done on-line (i.e., while connected to the Internet).

This assessment is worth 10 points (10% of your term grade). It is due on Wednesday September 20, 2006.

1. URLs, IP addresses, DNS names, tracert
   For this part, you will use utilities at the web site http://www.dnsstuff.com When you go to that site, you will see a number of places to type in web addresses and buttons to click on.

   1. First, go to the section marked DNS lookup.
      Type www.google.com in the box and click on Lookup. (Leave A selected in the drop-down list).
      What do you see? Can you find the numeric IP address of www.google.com?

   2. Second, go to the section marked Ping. Ping is a handy network utility that will test if a host is alive. It will also give you statistics about how long it takes to send a message to a host.
      Type www.google.com in the box and click on Ping.
      How long does it take to get a reply from google?

   3. Third, go to the section marked Traceroute. Traceroute is a handy network utility that will show you the route that messages take to get from you to a host.
      Type www.google.com in the box and click on Traceroute.
      How many "hops" does the message take?

   4. What happens if you type in a DNS name incorrectly? In your web browser, try going to
      http://www.brooklyn.cuny.e or http://www.brklyn.cuny.edu
      Try to ping them in dnsstuff.
   5. What happens if you type in an IP address directly, instead of a DNS name? In your web browser, try going to
      http://146.96.128.102
      Try looking up that IP address in DNS Lookup. What information can you find there?
   6. What if you type the IP address in incorrectly? In your web browser, try going to
      http://146.245.100.2.
      Try pinging 146.245.100.2

2. Visualizing the Internet
   
   1. Go to: http://www.mappingcyberspace.com/gallery/figure5_4.html
      Map B shows the number of domain names in New York City. The larger the bars, the more domain names there are in a region. Approximately which section of NYC has the most domain names?
   2. Go to http://www.mappingcyberspace.com/gallery/
      What are some of the other types of graphics available? Can you find the drawings of the early internet (ARPANET) topology from 1969 and 1977?
3. Participatory Web
   
   1. Go to: http://images.google.com/imagelabeler/
      This is one of a growing number of applications on the web that take advantage of the large number of internet users to solve problems collectively. How do you think the imagelabeler works?

PART II. using the internet tools

instructions

1. Begin by creating a file in Notepad.
   
2. Type your name in the file and your email address.
   
3. Type the answers to the questions (below) in this file.
   
4. Please label your answers so I know which answer goes with which question (e.g., "Part II, question 1").
   
5. When you are finished, print out the file and bring it to class no later than Wednesday September 20.

questions

1. (2 points) Trace the route from the computer you are currently using to the web sites listed below. For each site, list the number of hops in the route.
   • http://www.mta.info
   • http://www.brooklyn.cuny.edu
   • http://www.hunter.cuny.edu
   • http://www.columbia.edu
   • http://www.liv.ac.uk
   • http://www.unimelb.edu.au

   Look up each site in your browser and see what it is.

   On dnsstuff, look up the physical location of each of these web servers. (Click on DNS Lookup, as we did in the lab. When you get to the screen with the answer, click on that IP address and you'll see a page called WHOIS that tells exactly where the server is located.)

   In your homework file, for each address, write down what the site is, where the server is located and the number of hops to the site.

   Then, answer this question:
   What can you say about the relationship between the physical proximity of each of these web servers to your current location and the number of hops? i.e., are fewer network hops required to reach machines that are physically closer to you?

2. (2 points) Look up the (numeric) IP address of the following web sites:
   • http://www.amazon.com
   • http://www.amazon.co.uk
   • http://www.amazon.fr
   • http://www.amazon.co.jp
   • http://www.amazon.ca
   • http://www.amazon.de
   • http://www.amazon.at

   Look up each site in your browser and see what it is.

   Look up the physical location of each server.

   In your homework file, for each address, write down what the site is and where the server is located.

   Then, answer these questions:
   What can you say about the relationship(s) amongst these web sites and web servers?
   What did you learn about their physical location(s)?
   Explain how the numeric IP address provide hints to these servers' relative locations.

3. (1 point) Go to http://www.google.com Search for biomedical computing. How many results are there (approximate total)? What are the first three non-sponsored URL's found?
   Go to http://www.altavista.com Search for biomedical computing. How many results are there (approximate total)? What are the first three non-sponsored URL's found?
   Go to http://www.ask.com Search for biomedical computing. How many results are there (approximate total)? What are the first three non-sponsored URL's found?

   In your homework file, list the number of results and top 3 non-sponsored sites found by each search engine.
   What are some of the differences between the three engines?
   Which engine would you use if you were looking for a definition of the term "biomedical computing"?

PART III. off-line questions

To answer the questions in this part, you do not need to be connected to the Internet. However, you will need to use a computer to run Notepad and type your answers into a file.

1. Define the Internet and the World Wide Web, and explain the difference between them.
   (1 point)

2. Define a server and a client, and explain the difference(s) between them.
   Give some (at least 3) examples of types of servers.
   (1 point)

3. Provide definitions for the following abbreviations. Give the term that the abbreviation stands for as well as a short explanation of what the term means.
   (2 points)
   
   • CPU
   • RAM
   • URL
   • FTP
   • HTTP
   • IP
   • TCP
   • UDP
   • DNS
   • HTML

4. Define biomedical computing. List any references (e.g., URLs, books, etc) that you used to help learn the definition. Don't plagiarize! Write your answer in your own words. (1 point)