SS 2 First Term

LEARNING OBJECTIVES: BY THE END OF THE LESSON STUDENTS SHOULD BE ABLE TO:

Cognitive	i. Define a network topology and name the main types. ii. Compare bus, star, ring, mesh, tree and hybrid topologies. iii. Describe the OSI and TCP/IP reference models. iv. Classify networks as PAN, LAN, MAN or WAN.
Affective	i. Appreciate the value of Computer Networks in school, at home and in the community. ii. Show willingness to use digital tools carefully, safely and responsibly.
Psychomotor	i. Draw a star and a mesh topology and label each device. ii. Use a table to compare the strengths and weaknesses of the topologies. iii. List the seven OSI layers in order. iv. Classify five networks by the area each covers.

Rationale: A network topology is the arrangement of the devices in a network and the connections between them. Understanding what is a Network Topology?, bus Topology, star Topology, ring Topology helps learners use digital technology confidently, safely and responsibly.

Pre-requisite Knowledge: In Week 6, learners studied Logic Gates and Digital Logic, including what is a Logic Gate?, the AND Gate, the OR Gate. The knowledge from that week is used again in this lesson.

Learning Material/Teaching Aid: Whiteboard, markers, computer or laptop where available, printed notes and charts on Computer Networks, practical task sheets, learners' notebooks and pens.

Reference Materials: Digital Technology for Senior Secondary Schools (SS 2); NERDC Digital Technology Curriculum; Digital Technology SS 2 First Term Notes (Week 7); First Term examination and Continuous Assessment question papers.

LESSON DEVELOPMENT

Stage/Step (Time)	Teacher's Activities	Student's Activities	Learning Points
Introduction 5 MINUTES	Welcomes learners, revises Week 6 (Logic Gates and Digital Logic) with two quick oral questions, and asks what they already know about Computer Networks. Elicits responses and writes the topic on the board.	Recall the previous lesson and share what they already know about Computer Networks.	Connecting prior knowledge to Computer Networks.
Step 1 6 MINUTES	Covers What is a Network Topology?: A network topology is the arrangement of the devices in a network and the connections between them. Covers Bus Topology: In a bus topology all devices connect to a single central cable called the backbone. Covers Star Topology: In a star topology every device connects to a central switch or hub with its own cable, and data passes through the centre first. Also covers Ring Topology, Mesh Topology and Tree (Hierarchical) Topology.	Listen, take notes and answer oral questions on "What is a Network Topology?" and related points.	Understanding: What is a Network Topology?; Bus Topology; Star Topology; and related ideas.
Step 2 6 MINUTES	Covers Hybrid Topology: A hybrid topology combines two or more topologies in one network, such as stars inside offices joined by a mesh backbone. Covers Why Network Models Exist: Computers from different manufacturers use different hardware, so networking needed common rules called protocols. Covers The OSI Reference Model: The Open Systems Interconnection (OSI) model, published by the ISO in 1984, is a seven-layer reference model for networks. Also covers The Seven Layers of the OSI Model and The TCP/IP Model.	Copy the key points, give examples from school and everyday life, and ask questions on "Hybrid Topology" and related points.	Understanding: Hybrid Topology; Why Network Models Exist; The OSI Reference Model; and related ideas.
Step 3 6 MINUTES	Covers Comparing OSI and TCP/IP: OSI and TCP/IP describe the same journey in different detail. Covers Client-Server and Peer-to-Peer Models: In the client-server model a central server stores resources and manages data, while client computers request those resources. Covers Corporate Networks: A corporate network is a private network that connects computers, servers and devices within an organisation or across branches. Also covers Network Protocols in Business and Network Security Measures and Threats.	Discuss in pairs, then report one point on "Comparing OSI and TCP/IP" and related points to the class.	Understanding: Comparing OSI and TCP/IP; Client-Server and Peer-to-Peer Models; Corporate Networks; and related ideas.
Step 4 6 MINUTES	Covers Meaning and Uses of Networks: A computer network is two or more computers joined so that they can exchange data and share resources. Covers Classes of Network: A personal area network covers a very small area, usually a few metres, such as a phone connected to a headset. Covers Network Devices: A modem converts a signal from the provider into a signal the computer can use, and back again. Also covers Topology and Wired and Wireless Connections.	Respond to questions, complete the examples on the board and note down "Meaning and Uses of Networks" and related points.	Understanding: Meaning and Uses of Networks; Classes of Network; Network Devices; and related ideas.
Practical Work 6 MINUTES	Guides learners through the practical work: (i) Draw a star and a mesh topology and label each device. (ii) Use a table to compare the strengths and weaknesses of the topologies. (iii) List the seven OSI layers in order. Moves round the class to check progress and correct unsafe or careless use.	Carry out the practical tasks individually or in pairs and record what they did in their notebooks.	Applying the lesson through hands-on practice.
Evaluation 3 MINUTES	Asks learners to: i. Define a network topology and name the main types. ii. Compare bus, star, ring, mesh, tree and hybrid topologies. iii. Describe the OSI and TCP/IP reference models. iv. Classify networks as PAN, LAN, MAN or WAN.	Respond verbally and in writing to the evaluation questions.	Assessment and consolidation of the lesson content.
Conclusion 2 MINUTES	Recaps the main points: what is a Network Topology, bus Topology, star Topology, ring Topology, mesh Topology. Links them to the assignment and previews Week 8: The Internet and Online Safety.	Listen, ask questions and copy the assignment.	Reinforcement of key concepts and a preview of the next lesson.

Assignment: i. A school lab is wired in a star. Explain why a cut cable affects only one computer. ii. A company needs the most reliable network and will pay for it. Recommend a topology.