COMP247 Data Communications
Assignment 1, 2019
Due: Sunday 7th April, 2019, 11:59 pm Marks: 60, Value: 15%
This assignment is designed to help you develop skills and strengthen your understanding of data communications.
Ensure that you read and adhere to the following instructions:
Answer Q1 as if it were an exam – layout your answer in a readable format and include all relevant working. Your answer to Q2 will require supporting arguments and references that cite your research, since this is a networking unit you should use IEEE referencing style. Your assignment will be submitted electronically via TurnItIn on the COMP247 iLearn page. All submissions must be in PDF format — do not submit a MS-Word file. Also, ensure that your report does not include the question text.
Question 1 (30 marks) – Subnetting and the network layer
a) [9 marks] What are the equivalent subnet masks in dotted-decimal notation for the following slash-notation address blocks?
i) /21 ii) /13 iii) /29
b) [9 marks] What is the maximum number of hosts that can be addressed on the following networks?
i) /19
ii) /30
iii) /23
[12 marks] Are the following netmasks legal? If so, what are their slash-notation forms? If not why are they not legal?
i) 255.255.224.0 ii) 255.128.0.0
iii) 255.252.255.0 iv) 255.255.255.254
c)
Question 2 (30 marks) – Applications, Protocols and Layering.
Choose two applications from the list below. You should make your selections so that you are able to describe both points of similarity and points of difference when answering the questions that follow.
•
•
•
•
•
•
•
Answer the following questions about both of your chosen applications.
a) [2 marks] What application-layer protocol do each of your applications use? (If either of your applications use more than one protocol, decide which protocol is the main one)
b) [10marks]Giveabriefsummaryofwhateachofyourprotocolsdoesinrelationtothe application. (2-3 lines for each protocol)
c) [2 marks] Which transport layer protocol(s) does each of your application layer protocols use?
d) [10 marks] For each, why do you think the particular transport layer protocol was chosen by the application protocol designer? (2-3 lines for each protocol)
e) [1 mark] Choose one of your applications; which application architecture does your protocol use? (ie. Client-server, peer-to-peer, thin-client, thick-client, etc.)
f) [5 marks] For your chosen application provide an explanation of why this application architecture is used. (2-3 lines)
Electronic file transfer
Electronic mail
Bit-torrent
Internet Relay Chat (IRC)
The Domain Name System (DNS)
IP Telephony (VoIP, not Skype or Facetime, etc.)
Real-time streaming (Not web-based solutions such as Youtube, Facebook, Instagram, etc.)
Assessment
For all questions in this assignment not only content but also presentation will affect your mark. You will lose marks 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 taken into account in assessing its presentation.
For full marks, your answers should be well argued, clear, and coherent.
The standards of marking described in the unit outline L.O. 1 and L.O. 2 will be applied to this assignment as relevant to the assignment topics.
In addition, the following particular standards will be applied in marking this assignment: • Spelling and grammar:
o Assignment submissions with more than 4 spelling or grammatical errors will not achieve a grade higher than distinction; submissions with more than 8 such errors will not achieve a grade higher than credit.
• Clarity:
o Ambiguous or poorly worded answers will receive a grade no more than a
pass for the individual question.
o Minor issues of clarity will receive a grade no more than credit for the individual question.
• Correctness of approach taken and answer obtained:
o Incorrect answers with the correct logic or approach will receive no more
than a pass for the individual question.
o Correct answers with incorrect logic or approach will receive no more than pass for the individual question.
o Incorrect answers with no explanation of the approach taken or with the incorrect approach will receive a fail grade for the individual question.
The questions will be marked individually, the marks totalled, 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.
Submission
Submit on the iLearn page under ‘Assignments Section’. The submission is with a tool called TurnItIn. This cross checks for online papers and other student papers for any plagiarism (copying). In short – DON’T COPY – or get others to do your assignment, we are pretty good at catching people out and the consequences can be severe. Do not trust anyone who will take money to do assignments. They can take money from several students, return the same assignment, and you get caught. They don’t care, but we do!