Name:______

COSC 406: Data Communication Systems Homework #1 Due on Monday, Feb 06, 2006 20 points Instruction for handing in homework: Use this sheet as the cover page for your homework assignment. Write your name in the space provided above and staple your solutions to this sheet before handing in.

Probing the Internet

The tools you will use are “ping” and “traceroute” of Windows.

NOTE: DO NOT USE CAMPUS COMPUTERS to use ping and traceroute. Note: The command for traceroute is actually "tracert" on Windows environment

On the following web sites, perform a ping and traceroute from a workstation preferably from your home: www.umd.edu (University of Maryland, College Park, MD, USA) http://www.nasa.gov (National Aeronautical & Space Agency, USA) www.jadavpur.edu (Jadavpur University, Calcutta, India)

Exercise 1 For each URL, a) Find out packet size b) Find out the round trip minimum, average, and maximum times from ping c) Find out the number of hops between the two computers

Give your results in a tabular form. Repeat the process between 8am-10am, 12pm-2pm, 4pm-6pm, and 10pm- 12am. Does the ping and traceroute results for a) to c) differ for each URL? Write your observations. Are the data transmission route for each URL same. Draw the network for each Website.

Instructor: Sisir Ray Exercise 2

Traceroute on following two websites and write your observations: 1. www.microsoft.com 2. public.web.cern.ch or cdsweb.cern.ch (CERN is Council European for Nuclear Research) – the first URL of CERN is its homepage and the second one is CERN Document Server – it has thousands of articles and documentations

NOTE: To break any infinite loop search, you may use keyboard keys: CTRL + C or CTRL + Break

Exercise 3

Perform ping and traceroute for any of the above URLs by changing the packet size from default to some other size (say 64 or 128 bytes). If required, use the Windows Help windows for ping and traceroute.

Exercise 4

Internet technology is documented in a series of reports known as “Request For Comments (RFC)”. RFC 2151, which can be found on the CD-ROM that accompanies this text or Internet, describes tools available on the Internet. What tools does the RFC document describe that are not described in this chapter? Give details as much as possible. Your score depends on how much you investigate on it.

Instructor: Sisir Ray