SIT202 Computer Networks Trimester 2, 2020 Problem Based Learning Task 2
Due Date: 8pm Sunday September 27th, 2020
This assessment is marked out of 100 marks and is worth 35% of your final unit mark.
All work completed/submitted as part of this assessment task must be your own, individual work. Any content drawn from other materials, including unit materials, must be clearly quoted where appropriate, and/or clearly referenced. All students should review and be familiar with the content provided by the University regarding how to reference other materials:
https://www.deakin.edu.au/students/studying/study-support/referencing
And in particular the information provided regarding Academy Integrity:
https://www.deakin.edu.au/students/studying/academic-integrity
Use of Illustrations
Note that several questions below may require you to include an illustration in your answer. This must be your own illustration, not a graphic copied from the Internet or any other source (textbook, class slides, etc.). Illustrations from the Internet (whether directly copied or reproduced by you) will not be awarded any marks.
There are many illustration programs that you may use for this purpose, including several free applications accessible via the Web. If you are unable to use these programs however, you may include a scanned/photographed hand-drawn illustration in as long as that illustration is clearly legible.
HD Tasks
Note that there are one or more ¡°HD Tasks¡± identified in the requirements below. These tasks are more difficult to answer and total 20% of the marks available for this assessment. A HD result reflects achievement in the unit of a deep understanding of the unit content and ability to extend your knowledge beyond that covered in the unit directly. You can expect these tasks will be assessed harder than other tasks reflecting demonstration of this level of achievement.
This assessment task must be completed individually,
group work and/or collaboration with other students is prohibited.
Submission
Answers must be submitted via the unit site (CloudDeakin) to the TurnItIn-enabled folder for Problem Based Learning Task 2. Answers to each question and sub-question must be clearly identified in your submission. Acceptable file formats include Word documents, PowerPoint documents, PDF documents, text and rich text files, and HTML. Compressed files such as ZIP files or RAR files, or any other format that cannot be processed by TurnItIn cannot accepted and will not be marked.
Extensions
Applications for an extension can be made before the due date/time via the tool in the unit site (CloudDeakin). The link to the extensions tool can be found by clicking on the Assessments menu at the top of the screen and selecting the Extension Request link. Extension applications must clearly explain unusual circumstances that have impacted your studies and must contain enough information for the duration of any extension to be determined. Students applying on the basis of a LAP must at a minimum indicate they are supported by a LAP and indicate that the request for an extension is linked to the disability.
Applications for special consideration can be made at any time including (for a limited time) after the due date/time. Information on applying special consideration can be found here:
https://www.deakin.edu.au/students/studying/assessment-and-results/special-consideration
Note: Applying for an extension or special consideration does not guarantee a positive outcome. You should always continue working on the basis that an extension is not granted, such as submitting any work you have completed by the original due date/time to avoid a late penalty. If an extension is then granted you can resubmit an updated version of your assessment later.
Question 1 / Week 6 (12.5 + 8 = 20.5 marks) Computer networks are constructed using a modular architecture known as layering.
a) Identify and describe the five different approaches to configuring IPv6 addresses. In your answer, explain why it may be beneficial to use stateless DHCPv6.
b) (HD Task) Consider the following weighted graph: A2B2C
4151
D3E
Demonstrate the step-by-step calculation of the least-cost tree starting from node A using Dijkstra¡¯s Algorithm and draw a figure illustrating the final least-cost tree.
Question 2 / Week 7 (12 + 6 = 18 marks)
a) Transport protocols usually provide multiplexing and demultiplexing services. Explain how this works and why it is necessary.
b) (HD Task) Sliding-window flow control provides both flow control and error control. The TCP protocol implements a variant of this, where an acknowledgement can be sent for segments received without granting permission for additional segments to be sent. If the underlying IP protocol were modified to provide a reliable service, guaranteeing that all segments sent by TCP arrived at the destination without error, explain why it would still be useful to separate the acknowledgement and the granting of permission.
Question 3 / Week 8 ((3 + 7 + 5) + (4 + 2) = 21 marks)
a) Select three popular Internet domains, examples of which could include amazon.com, facebook.com, google.com, microsoft.com, reddit.com, or any other popular domains of your choosing.
i. Obtain the SOA records for each of your chosen domains and present their data in a table.
ii. Briefly explain the meaning of each field.
iii. Discuss how the observed different values will impact other DNS servers.
b) (HD Task) We have examined the HTTP protocol in this week¡¯s materials. For constrained devices such as IoT devices, alternative protocols such as the Constrained Application Protocol (CoAP) are often used instead.
i. Describe the CoAP protocol.
ii. Explain why CoAP might be preferred for constrained devices.
Question 4 / Week 9 (8 + 12 = 20 marks)
a) In Week 9 on Slide 6, a figure is shown illustrating SNMP querying how many UDP datagrams have been received by an agent (the agent could be an individual host or a router). Explain how such simple data can be made useful.
b) One of the problems encountered for multimedia is jitter. Explain how a playback buffer solves the problem of jitter and discuss whether a playback buffer is useful for live events such as a video call/conference.
Question 5 / Week 10 (8 + (5 + 7.5) = 20.5 marks)
a) Digital signatures work by generating and signing a digest of a message. Explain why only a digest is signed and why it isn¡¯t necessary to sign the entire message.
b) Consider an organisation that has two sites (offices, branches, etc.), each with a typical connection to the Internet via an ISP (such as an NBN connection like many Australian homes). To secure communication between the two sites, a site-to-site VPN has been established using IPsec ESP in tunnel mode.
i. Draw an illustration showing the two sites and their connection to the Internet, the VPN tunnel, packets travelling between the individual sites and public Internet sites, and packets travelling between the sites.
ii. Briefly discuss the advantages of this approach and explain the services provided by the VPN.