You are asked by a start-up company to design the complete network set-up for their operation. The company’s business model is to develop and sell mugs that can be controlled by an app from the smartphone (for instance, the app would let the user determine whether a particular mug is still clean, or to locate a clean mug). The company wants to be able to do the following:
1. Sell the mugs and provide customer support on the web.
2. Communicate with the customer via e-mail.
3. Design and develop the mug and the app and additional support software in their offices.
4. Perform typical office tasks (e.g. accounting) in their offices.
5. Allow their employees to work remotely.
The company currently has 5 employees, who share all tasks and work in the same office or at home. However, rapid growth is anticipated, and the company expects to have dedicated teams (e.g. sales, development, accounting, web) and several offices in the same building soon. In addition, while the company prefers its employees to work in the office, it is aware of the risk of a future lockdown and wants to be prepared for it.

Your task is to design a network that
• supports all of the requirements
• enables the company to grow
• is cost-efficient and secure
Your proposed network may employ both physical components and external services.

1. Describe a suitable network architecture. Your answer should include:
a. A summary of your interpretation of the scenario (max. 1 paragraph), and a list of technical requirements to support the needs of the company (at least 3 requirements). [4 marks]
b. A network diagram and a discussion of the types of components used and the topology. Give a reason for your choices. [3 marks]
c. Concrete examples for the use of addressing schemes in your network. Illustrate at least one machine-readable and one human-usable addressing scheme by appropriate examples. [4 marks]
d. A discussion of at least 2 specific models/products to be used and why these would be optimal. [4 marks]
e. Some consideration for security issues. Name and discuss at least one potential issue. [2 marks]
f. A discussion of challenges that may be caused by a local lockdown, and adaptations that may be necessary to enable the company to work throughout it. [5 marks]
2. Identify two application-layer protocols that would be used in the network. For each protocol,
a. Give a reason why the protocol would be used. [1 mark]
b. Name at least two components that would use the protocol. [1 mark]
c. Identify two causes of failure of the protocol, and the consequences a failure would have on the business. [1 mark]
d. Discuss security issues of the protocol, and how they could be avoided. [1 mark]
e. Show an example of the messages exchanged by the protocol in your network. [1 mark]
3. Identify a component or service in your network that may be a performance bottleneck. Choose and apply a suitable performance evaluation approach from those discussed in the lectures. For your approach:
a. Describe the bottleneck situation in detail. [3 marks]
b. Argue why your approach is appropriate for this situation. Which questions can it answer? Why do you choose this approach over one of the others? [2 marks]
c. Describe the application of the approach. Discuss parameter values, model choices, and outcomes. Use graphs where appropriate. [5 marks]
d. Discuss limitations of your evaluation. [2 marks]
4. Identify a dependability issue in your network. This may be in a component or a service. For this issue:
a. Describe the issue in detail. [2 marks]
b. Give a suitable metric to assess the dependability. State why the metric is applicable here, which data you need to compute it, and show an example computation of the metric. [3 marks]
c. Discuss the application of a suitable mechanism to improve dependability. [2 marks]
5. Reference all your sources in an accepted reference style throughout. [2 marks]
6. Your report must be well-structured. It must be possible to understand the main argument in a single reading. [2 marks]

Learning Outcomes Assessed

[LO01] Identify the social, economic and ethical issues that arise from the use of communication networks & associated technologies.
[LO02] Demonstrate an understanding of deploying communication networks and their potential security, performance, and dependability implications and trade-offs. [LO03] Describe the fundamental principles and protocols of wired and wireless communication networks.
[LO04] Demonstrate an understanding of performance and dependability evaluation approaches for communication networks.

Criteria for assessment – Credit will be awarded against the following criteria.

Credit as indicated in the assignment will be awarded against the following criteria
• Completeness
• Clarity
• Correctness
Please note: Your work will be checked for collusion and plagiarism both automatically and manually. Any suspicion of Unfair Practice will be reported to the Unfair Practice Coordinator and could result in you being subjected to the Unfair Practice Procedure. If you are found guilty, consequences may include a mark of zero for the coursework as well as exclusion.

To avoid this, keep in mind:
– This is an individual assignment. Do not collaborate with other students, and do not share your work with others.
– Do not copy material from anyone.
– Properly reference all external material you use. Employ either the Cardiff Harvard Referencing style or any other style common in Computer Science (e.g. an ACM citation style), but be consistent throughout.

If you are in doubt whether you may be committing unfair practice, please check the University’s guidelines on referencing and contact your personal tutor and/or the module leader.