Computer Networks
Overview
Two computers on the same desk have nothing whatever to say to each other unless somebody has agreed, in advance and in enormous detail, how they will say it. What voltage means a 1. How big a chunk of data may be. What the receiver does if a chunk goes missing. How a machine on this side of the world is even addressed from the other. None of that is obvious, none of it is optional, and all of it is what a network protocol is for.
This lesson builds a network from the ground up. You will learn what a computer network is and what it costs as well as what it buys, the difference between a local and a wide area network, when to run a cable and when to go wireless, and how the star and bus topologies behave when something breaks. Then you will meet the protocols this specification names, the four layer model that organises them, and the four methods of network security you are expected to explain.
Objectives
- Define what a computer network is. Discuss the benefits and risks of computer networks. Describe the LAN and WAN types of computer network:
- Local Area Network (LAN)
- Wide Area Network (WAN).
- Understand that networks can be wired or wireless.
- Discuss the benefits and risks of wireless networks as opposed to wired networks. Explain the following physical network topologies:
- star
- bus.
- Define the term ‘protocol’.
- Explain the purpose and use of common network protocols including:
- Ethernet
- Wi-Fi
- TCP (Transmission Control Protocol)
- UDP (User Datagram Protocol)
- IP (Internet Protocol)
- HTTP (Hypertext Transfer Protocol)
- HTTPS (Hypertext Transfer Protocol Secure)
- FTP (File Transfer Protocol)
- email protocols:
- SMTP (Simple Mail Transfer Protocol)
- IMAP (Internet Message Access Protocol). Understand the need for, and importance of, network security. Explain the following methods of network security:
- authentication
- encryption
- firewall
- MAC address filtering.
- Describe the 4 layer TCP/IP model:
- application layer
- transport layer
- network layer
- link layer.
- Understand that the HTTP, HTTPS, SMTP, IMAP and FTP protocols operate at the application layer. Understand that the TCP and UDP protocols operate at the transport layer.
- Understand that the IP protocol operates at the network layer.
Mind map
This topic is mapped out so you can see how the ideas connect.
Open the mind map in the app
Lesson Note
Complete Note Available on the Green Bridge App
Get the Green Bridge CBT app on your phone or computer for the complete IGCSE library: past papers, mark schemes, mind maps, flashcards and audio lessons.
Lesson Evaluation
Congratulations on completing the lesson on Computer Networks. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.
You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.
Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.
- Which of these best defines a protocol? A. A physical cable joining two devices B. A set of rules that determine how data is communicated between devices C. A program that displays web pages D. The shape in which a network is wired Answer: B
- At which layer of the four layer TCP/IP model does the IP protocol operate? A. Application B. Transport C. Network D. Link Answer: C
- In which topology does a single break in the shared cable stop the whole network working? A. Star B. Bus C. Both equally D. Neither Answer: B
- Which protocol is used for sending email? A. IMAP B. FTP C. SMTP D. HTTP Answer: C
- What does MAC address filtering do? A. Scrambles data so it cannot be read in transit B. Allows or blocks devices based on the physical address in their network adapter C. Checks a user's password when they log in D. Splits data into packets for transmission Answer: B
Work through these questions in the app
Work through these questions in the app
Recommended Books
Practice Mock Questions
Want to practice mock questions on Computer Networks? Download the Green Bridge CBT app to access mock questions and full practice assessments for this topic.
Download The App On Google Playstore
Everything you need to excel in your exams
