School of Computing
Macquarie University
COMP3250 Computer Networks
Assignment #2 2022
Lecturer: Muhammad Sajjad Akbar
Due: Week 12 – Friday 28th of October 2022, 11:55 pm.
Total Marks: 30
Weighting (Value): 15%
Objectives
This assignment will test your knowledge in the following areas:
• Multicast
• TCP
• Security
Assignment Type: Problem Solving (Individual Assignment)
The purpose of the problem-solving assignment is to help the students to get accustomed to
dealing with real world problem situations/issues. It is designed to help students analyze a
particular problem and find its best solution.
Questions
Question 1 (a): [4 marks] A company has registered to receive 8 different channels of a high
andwidth video stream from a central facility via 8 different multicast groups. The company’s
network has the capability to support three active streams concu
ently. The company has support
for multicasting and uses version 1 of IGMP to manage its active groups. What problem do you
foresee with the use of IGMPv1 in this scenario? Provide a
ief explanation of the problem that
you have identified XXXXXXXXXXwords)
Question 1 (b): [3 marks] Although DVMRP has been deployed in the multicast backbone,
protocol limitations preclude the pervasive use of this technology in a large-scale inter-domain
setting. Identify and
iefly explain three (3) limitations of this technology XXXXXXXXXXwords)
Question 2: [10 marks] In this task, you will initiate a TCP handshake process by generating a
single HTTP request from your web
owser to download any image from the Internet. Using
Wireshark, you will observe, capture, and analyze the initial packets of this TCP flow. You are
equired to:
• [2 marks] Identify, record, and
iefly explain the fields of the SYN segment.
• [2 marks] Identify, record, and
iefly explain the fields of the SYN/ACK segment.
• [2 marks] Identify, record, and
iefly explain the fields of the ACK segment.
• [4 marks] Identify and record the sequence and acknowledgement numbers being
exchanged in this three-way handshake process and
iefly explain how these
numbers increment and what they mean.
Please provide the screenshots for each part of the question in your answer XXXXXXXXXXwords)
Question 3 (a): [5 marks] In IPSec, the ESP header provides both authentication as well as
confidentiality services whereas the AH header simply provides authentication service. Briefly
explain why would you still want to use both AH and ESP on a packet? (2 marks) Briefly explain,
with the aid of a figure, how the two headers can be used together and what security services
they provide in the tunnel mode. (3 marks XXXXXXXXXXwords)
Question 3 (b): [8 marks] SSL protocol is located between the application protocol layer and the
TCP/IP stack, where it can secure and send application data to the transport layer. In contrast,
IPSec is a network layer protocol suite which offers security to protect communications over public
networks. Consider a scenario in which SSL has already been deployed to secure communication
sessions to safely send messages over the network. Would there be a need to use IPSec in
conjunction with SSL or do you feel that this would be an overkill as SSL should suffice? Provide
an argument in favor or against the use of IPSec with SSL with suitable reasons/examples. (300-
350 words)
Assignment and Submission Guidelines
Submission
You must make an online submission on ilearn via Turnitin.
Assignments will normally be marked and returned online. There are no hardcopy submissions
for written assignments.
Ensure you submit the co
ect file. The submission process shows you a complete preview of
your entire assignment after you have uploaded it but before you have submitted it. Carefully
check through every single page to ensure everything is there and the co
ect version has been
uploaded, and only then press CONFIRM.
Note: Multiple submissions may be possible via Turnitin prior to the final due date and time of an
assessment task.
Teaching staff will use the originality report to judge whether plagiarism has occu
ed and whether
penalties should apply for
eaches of the Academic Honesty Policy. Any similar text identified
y Turnitin will be considered carefully to see if it is indeed a
each of the Academic Honesty
Policy.
Note
• Answers must be within the specified word limit. This is an absolute word limit, and no excess
will be allowed. This is an absolute word limit, and no excess will be allowed. If you exceed
the word limit, you will be subject to a penalty of 5% of the available marks (i
espective of the
number of words by which the word limit is exceeded). If you falsely claim the word-count of
an assessment to be under the limit when it is in fact above the limit is a form of Academic
Misconduct (deception) and can lead to even more severe penalties.
• Assumptions (if any) must be stated clearly in your answers. Note that there may not be one
ight answer for some of the questions. Rather, your explanations do need to present your
case clearly. The explanations you provide do not have to be long; a concise one is prefe
ed
to a rambling one.
Late Submission
From 1 July 2022, Students enrolled in Session based units with written assessments will have
the following late penalty applied. Please see https:
students.mq.edu.au/study/assessment-
exams/assessments for more information.
Unless a Special Consideration request has been submitted and approved, a 5% penalty (of the
total possible mark) will be applied each day a written assessment is not submitted, up until the
7th day (including weekends). After the 7th day, a grade of '0' will be awarded even if the
assessment is submitted. Submission time for all written assessments is set at 11:55 pm. A 1-
hour grace period is provided to students who experience a technical concern.
Assessment
For all questions in this assignment not only the contents but also the presentation will affect your
mark. You will lose marks (and not necessarily only a small portion) if there are problems with the
presentation, particularly with clarity. This means that your answers to each question should be a
coherent statement and that the spelling and grammar of your submission will be considered in
assessing its presentation.
For full marks, your answers should all be clear, coherent, and co
ect, and strictly within the word
limits. The standards of marking described in the unit outline L.O. 1-6 will be applied to this
assignment as relevant to the assignment topics. The questions will be marked individually, the
marks totaled, and a final grade assigned that is no more than indicated by the total marks, and
no more than allowed by the standards specified above and in the unit outline.
Plagiarism
In this assignment, you must be particularly careful to avoid plagiarizing your articles or any other
sources of information. Do not try to present someone else’s work as your own! The prescribed
penalty is an ‘F’ grade for the assignment. When you use a source other than yourself to write a
paper, you must cite that source. Sources available on the Internet must also be cited, including
the Web address of the site. If you take an original source and modify it to turn in as your own
work, you are also guilty of plagiarism. You need to write your own words and phrases that
express your own ideas and understanding. You should be well aware of the University's
plagiarism policy.
Referencing Style
• Must conform to a standard referencing style. Harvard and IEEE are the most commonly
ecommended styles of referencing.
• Choose a referencing style and use it consistently.
• All references must appear both in the body of the text as well as in the reference list provided
at the end of the document.