Lesson Notes By Weeks and Term v5 - Grade 10

Lesson Video

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Performance objectives

• Define and differentiate between network types (LAN, WAN, MAN, PAN).
• Identify and describe the function of common network hardware.
• Explain client-server and peer-to-peer network models.
• Define bandwidth and its importance in network performance.
• Explain the concept of IP addresses and differentiate between IPv4 and IPv6.

Lesson summary

Communication technologies and networks are the backbone of our modern world. From connecting with family in other provinces to accessing online educational resources and participating in the global economy, understanding how these technologies work is crucial. In South Africa, where access to information can be a catalyst for positive change and economic empowerment, knowledge of communication networks is not just about IT – it's about participating fully in the 21st century. Week 7 focuses on the fundamental concepts of these networks, providing a solid foundation for further learning in IT and related fields.

Lesson notes

2.1 Network Types Networks are categorized by their geographical scope: Personal Area Network (PAN): A network covering a very small area, typically around a person. Examples include a Bluetooth connection between a phone and headphones, or a Wi-Fi connection between a laptop and a printer. Think about using Bluetooth to connect your phone to your car’s speaker system for music. That's a PAN.* Local Area Network (LAN): A network covering a small geographical area, such as a home, school, or office. LANs allow devices within the area to share resources, such as files, printers, and internet access. Imagine your school's computer lab. All the computers connected so you can share printers and internet? That's a LAN.* Metropolitan Area Network (MAN): A network covering a city or metropolitan area. MANs are larger than LANs but smaller than WANs. They are often used by service providers to connect multiple LANs within a city. Consider a fibre optic network providing internet access to homes and businesses in Johannesburg. That constitutes a MAN.* Wide Area Network (WAN): A network covering a large geographical area, such as a country, continent, or the entire world. The internet is the largest WAN. WANs connect multiple LANs and MANs together. Cellular data networks (like MTN, Vodacom, Cell C) connect you to the internet almost anywhere in South Africa; they form a WAN.*

Example: A small business in Cape Town has a LAN in its office. This LAN is connected to the internet via a WAN provided by an internet service provider (ISP). The ISP's network might be considered a MAN within Cape Town. An individual at home uses a PAN connection to their smartphone, connecting to the internet via a WAN provided by a cellular network or fixed-line ISP. 2.2 Network Hardware Components Network Interface Card (NIC): A hardware component that allows a device to connect to a network. It provides the physical interface between the device and the network cable (or wireless signal). Every computer or phone connected to the internet has an NI

C. It allows the device to communicate with the network.* Hub: A simple device that connects multiple network devices together in a LAN. It receives data from one port and broadcasts it to all other ports. Hubs are less efficient than switches and are rarely used in modern networks. Think of a hub as a megaphone; what one device says, everyone else hears.* Switch: A more intelligent device than a hub. It learns the MAC addresses of devices connected to its ports and forwards data only to the intended recipient. Switches are more efficient and secure than hubs. Think of a switch as a targeted delivery service; it knows where to send the data directly.* Router: A device that connects multiple networks together. It forwards data packets between networks based on IP addresses. Routers are essential for connecting LANs to the internet. Your home Wi-Fi router connects your home network (LAN) to the internet (WAN).* Modem: A device that converts digital signals from a computer into analog signals that can be transmitted over telephone lines (or vice versa). Modems are used to connect to the internet via dial-up or DSL connections. While becoming less common, ADSL modems still provide internet access in some areas of South Africa.* 2.3 Network Models: Client-Server vs.

Peer-to-Peer Client-Server: In this model, one or more computers (servers) provide resources to other computers (clients). Servers typically provide centralized services, such as file storage, email, and web hosting. Think of a school computer lab; a central server stores all the student files and software, and the individual computers are clients accessing these resources.* Advantages: Centralized management, enhanced security, resource sharing.

Disadvantages: Requires dedicated server hardware, single point of failure.

Peer-to-Peer (P2P): In this model, computers share resources directly with each other. There is no central server. P2P networks are typically used for file sharing. Imagine sharing files directly between two laptops via Wi-Fi Direct. That's a P2P network.* Advantages: Easy to set up, no dedicated server required.

Disadvantages: Difficult to manage, less secure, performance depends on individual computer performance.

Example: A bank uses a client-server network. The bank's central servers store customer account information. Bank tellers use client computers to access this information. A group of friends shares music files using a P2P network application. 2.4 Bandwidth Bandwidth refers to the amount of data that can be transmitted over a network connection in a given period of time, typically measured in bits per second (bps), kilobits per second (kbps), megabits per second (Mbps), or gigabits per second (Gbps). Higher bandwidth means faster data transfer rates. Why is it important? Bandwidth directly impacts network performance. Insufficient bandwidth can lead to slow loading times, buffering, and lag.

Worked example

A school has 100 computers that need to access online learning resources. Each computer requires an average of 2 Mbps of bandwidth. What is the total bandwidth required for the school?

Total bandwidth = Number of computers * Bandwidth per computer

Total bandwidth = 100 * 2 Mbps = 200 Mbps

2.5 IP Addresses