CS 4390/5390 - Computer Networks
Homework Assignment #4
Due on August 2,  2009, 11:30pm.

Assignment Details

The goal of the assignment is to examine real protocols in use and understand the communication that takes place in a network by examining the bits that flow across a network segment. I collected a number of packets that are generated by running some network application between my desktop PC and some remote computers and put these packets into a file. The file is available at http://www.utdallas.edu/~kxs028100/cn/Homeworks/HW4.ethereal. You should first download this file and save it on your disk. This file contains the data that you will open and read with a network analyzer (Wireshark) and investigate. 

Using Wireshark: This is a GUI based tool that you can download from the web and run on your Windows and/or Linux machine. Once you start Wireshark, just go to File->Open menu to open the above given HW4.ethereal file and work with it. Wireshark has many options that are preconfigured and aims at helping the user with some common things. One of them is to use relative sequence and ACK numbers for TCP. In this assignment, you SHOULD NOT use these options. To unselect these options, go to Edit -> Preferences from the menu. In the Preferences window, select Protocols and go down to find TCP. The tool will display several options and you should UNSELECT "Relative sequence numbers and window scaling" box on the options.

It is important to realize that while we have gone over a most of protocols you will see, there may be some new stuff that you may encounter. You will have to use the class textbook and online sites as references to research the details of some of these. I will also try to provide some in-class time to answer questions so be prepared to ask questions when the time comes.

This assignment will be graded based on your ability to communicate that you understand everything about the packet trace. For this, you are expected to provide correct answers for the following questions:


Assignment Turnin

Please turn in a soft copy of your assignment via WebCT6. Good luck.