B227 Data Communications

Comments on Assignment 2 (Internal Students only)

For question 1a, I will not tell you exactly what commands you need to run, since part of the exercise is to get you to use the commands you have learnt creatively. USE YOUR BRAIN! Just think of yourself as a network administrator who want to find out as much about the network traffic as possible. I have mentioned response times as something you must have, but you can also include other aspects of network traffic which are interesting. The bulk of your marks will come from the required components as listed, though.

The easiest way to find machines outside of the lab to run tests is by locating web servers. For Murdoch University, you can pick a few machines from this listings of academic units. For Perth, you can pick from listings like yahoo.com listing of Perth sites. For Perth, pick machines which are relatively stable, like the ones for major universities. You don't want to run tests one day, and come back another day to find that the machines are no longer active. It would be a good idea to have a few tests to different machines as backup, in case one or two do go down. For the number of machines you need to try - don't go overboard. Just pick 2 or 3 from Murdoch, and 2 or 3 from Perth, and that will be sufficient. For the internal lab, you only ever need to test the connection with one other machine, since in a broadcast network, everyone gets the same packets.

As for how many times you actually need to run tests - again, don't go overboard. I'm only expecting you to run your test about 5 or 6 times over a week (2 or 3 times on 2 different days). You can verify your data by doing the same over another week if you want to (but is not necessary). If you have a definite strategy on what tests to run, it should not take you more than 15 minutes each time to collect the data. As to when you should run those tests, USE YOUR BRAIN! Pick the times which you believe will show differences in traffic characteristics. You will need to analyse them, as stated in the question. Even similarities in traffic at different times can give interesting analysis.

To collect the data from your tests, either write them down as they appear on the screen (you only need to submit a summary), or redirect the output to a file, and FTP the file to another account (eg. your university student account) which allows you to print and include in your assignment document.

For questions 1b and 1c, you do not need to actually do any tests (since I won't actually be creating a fault for you to find). Just outline a strategy for solving the problem.

For question 2, the answers for all questions should take only a few lines - a full paragraph at most. The challenge is to come up with the answer. Some answers are straight-forward, but some are quite in depth, will require some thinking. Make sure you know the lecture and textbook material well.

H.L. Hiew
Unit Coordinator