Your task in this assignment is to investigate one only of the following topics in computer network architecture, and submit a report on your findings. Note that the topics are about, or related to, application-level protocols in the Internet. Each of the topics has a "theory" section, where you have to look up the information somewhere (presumably on the 'net), and a "practical" section where you have to demonstrate how the particular system under discussion actually operates in practice. You must complete both sections to gain a high mark.
Note also that additional topics might appear on this page as they are suggested to me. It could be worth checking back regularly if you don't like any of those given below.
HTTP
.
GET
a Web page from
the proxy server. Can you tell if the page was cached? How?
NNTP
protocol, the basis of the
"USENET" (or "netnews") electronic news system, with attention
to some or all of the following points: what are some of the basic NNTP
commands? How do you discover available newsgroups on a server? What is an
"active" file? How do you discover a list of articles in a newsgroup? How
you fetch a desired article? How do you "post" a message to a newsgroup?
Who is Emily Postnews?
latrobe.test
,
or some other appropriate group, using an appropriate software application.
Save your posted message from your favourite news reader software and
analyse its headers. Attempt to post a message using NNTP
directly by the use of telnet
to the NNTP
port on the server.
ironbark
(or some other timeserver if you
know a better one). Document the steps involved. How does your system
handle timezones? How accurate would you
expect your system's clock to be when set from a remote system? Note that if
you don't dial in, you can't really do this question
HTTP
GET
or HEAD
request (as appropriate) to
a server (or proxy server) and then inspect the value of the
"Content-length:
" header line to discover the size (in bytes)
of the document. This could be (for example) launched from the Unix command line
something like:websize http://ironbark.bendigo.latrobe.edu.au/index.htmlwhich will simply send the number of bytes to
stdout
. For
really keen students: fetch the actual page, and additionally
discover the size of all images loaded with the page (using the
IMG
markup), and display the aggregated total. This is
much harder, and if you can get it working, will surely earn you an "A".
NNTP
commands to fetch and nicely format information from a news server such
as news.latrobe.edu.au
. For example, you could list all
current "active" newsgroups, or you could show the "description string" associated
with most (some?) newsgroups. Again, any really keen students
could build a utility to do something useful like check the contents of a user's
.newsrc
file (or whatever it's called on systems other than
Unix) to check for consistency with the groups listed on the server.
text/html
sent to
cnsubmit@ironbark.bendigo.latrobe.edu.au
, as for the
first assignment. Your choice of submission format will not affect
the mark gained for your assignment.
Submissions must, as usual, adhere to the requirements of the La Trobe
University, Bendigo Assignment Guide.This assignment carries 15% of your mark for Computer Networks.
Due Date: Monday, October 5th, 1998, 9am
Lecturer: Phil Scott, 5444 7277, p.scott@latrobe.edu.au.