AS91908 Analyse an area of computer science
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Time Given: 3 hours (split between 2 externals).
Exam Day: 9th of September (Monday of week 8 in term 3) Area of Computer Science: Network communication protocols |
Standard: AS91908
Version: 1 Level: 3 Credits: 3 |
Exam task: Candidates will be required to respond in short and/or extended answers (800–1500 words in total) to questions relating to their choice of ONE of the following areas of computer science:
For network communication protocols, questions may cover: the internet protocol suite and its four abstraction layers (application, transport, internet, and link), application layer protocols (HTTP / HTTPS), transport layer protocols (TCP and UDP), traffic analysis, network optimisation (e.g. queueing theory, predictive maintenance, patterns, anomalies, security threats), encapsulation and decapsulation, and security (SSL / TLS).
Over the next few weeks we will cover the above topics (their purpose, how they work, etc.), and seek to be able to make insightful conclusions (this being the requirement for obtaining Excellence). Examples of insightful conclusions include:
- big data
- complexity and tractability
- network communication protocols
For network communication protocols, questions may cover: the internet protocol suite and its four abstraction layers (application, transport, internet, and link), application layer protocols (HTTP / HTTPS), transport layer protocols (TCP and UDP), traffic analysis, network optimisation (e.g. queueing theory, predictive maintenance, patterns, anomalies, security threats), encapsulation and decapsulation, and security (SSL / TLS).
Over the next few weeks we will cover the above topics (their purpose, how they work, etc.), and seek to be able to make insightful conclusions (this being the requirement for obtaining Excellence). Examples of insightful conclusions include:
- innovative and imaginative connections
- exploration of less obvious implications
- making justified predictions
- suggesting improvements
- making justified generalisations that could be applied beyond the area itself
- use of higher-level thinking skills such as synthesis.
Very Important Note
Across these lessons it is essential that you engage with all of the tasks. In the majority, these are written tasks where you MUST write/type the answers yourself, DO NOT copy/paste. Writing things down forces your brain to engage and understand things better and triggers further thoughts and questions. If you just copy/paste you are doing yourself a disservice.
Across these lessons you will use the information to compile your own set of notes. One of the best ways to remember this kind of information in is simply to write it out, study it, then challenge yourself to write out pieces of your own notes from memory. See how close you were to the source material and adjust your notes/understanding.
Across these lessons you will use the information to compile your own set of notes. One of the best ways to remember this kind of information in is simply to write it out, study it, then challenge yourself to write out pieces of your own notes from memory. See how close you were to the source material and adjust your notes/understanding.
Network Communication Protocols
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The Internet Protocol Suite is a set of protocols that allow for the reliable and seamless transmission of data from end to end across the Internet.
The diagram on the right shows the four abstraction layers of the Internet Protocol Suite and a few examples of some protocols used within those layers. The Internet Protocol Suite is the most commonly referenced layering model for TCP/IP and serves as the backbone for data transmission on the Internet, as well as in other types of networks. This comprehensive suite encompasses a well-defined set of protocols that work together to ensure the reliable and seamless flow of data from its source to its destination. With its widespread adoption, the Internet Protocol Suite has revolutionised global communication, enabling the exchange of information on an unprecedented scale while ensuring the robustness and integrity of the transmitted data. |
The four abstraction layers of the Internet Protocol Suite
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The Internet Protocol Suite features four main layers:
Tasks:
1) Think of a few things that you use the Internet for and in roughly 150 words, explain how the Internet Protocol Suite allows this to happen?
2) Imagine that you have to explain to a friend about what the Internet Protocol Suite is and its purpose, write this down in 150 - 200 words. You can use this page and other resources to write your response, but pretend that you didn't have access to these when explaining to your friend.
- The Application Layer. If we think in levels then this is the topmost level and provides communication services directly to applications and end-users. Protocols at this level include (but are not limited to) HTTP and HTTPS. HTTP (Hyper Text Transfer Protocol) enables web browsing in browsers (Chrome, Firefox, etc.). HTTPS is a secure form of HTTP that allows for data to be securely encrypted and passed across the Internet.
- The Transport Layer. This features 2 main protocols: TCP (Transmission Control Protocol) and UDP (User Datagram Protocol). The former of the two guarantees reliable transfer of packets that are delivered in order, error detection, and retransmission of lost data packets. TCP establishes a connection and then splits data into packets that are then put back together in the correct order at the receiving end. It can manage flow and congestion which makes it suitable for applications that require error-free and ordered data transfer such as web browsing, file transfer, and email.
UDP does not have these guarantees and thus can involve packet loss and packets arriving out of order, however, it is a lot faster. UDP is connectionless and operates in a best-effort fashion which makes it suitable for situations where lower latency is a higher priority like streaming media, gaming, and VoIP. - The Network Layer (sometime called the Internet Layer). This layer is managed by IP – Internet Protocol. At this layer devices are given IP addresses (192.168.1.1) and manages the routing and delivery of packets between devices.
- The Link Layer. This is the lowest layer of the Internet Protocol Suite and is largely focused on managing devices on a local network. The Link Layer facilitates communication between devices connected locally to the same network.
Tasks:
1) Think of a few things that you use the Internet for and in roughly 150 words, explain how the Internet Protocol Suite allows this to happen?
2) Imagine that you have to explain to a friend about what the Internet Protocol Suite is and its purpose, write this down in 150 - 200 words. You can use this page and other resources to write your response, but pretend that you didn't have access to these when explaining to your friend.
