Unit 1.5 - Network Topologies, protocols and layers Lesson 1

Big picture Most computers and devices are connected together via networks. This opens up new opportunities and advantages. What are the advantages?

Learning Objectives Students will be able to identify a Star and Mesh Topology Students will be able to compare Advantages and Disadvantages of Wi-Fi and Ethernet Understand and explain what encryption is and why it is required

What is a Network? A computer network is a number of computers linked together to allow them to share resources. Networked computers can share hardware, software and data. BBC Bitesize

Engagement Activity Networks are all around you, in school, at home in businesses and hospitals. Think about what these networks look like Draw a diagram to represent one of these networks. Include the parts, devices and wires Be ready to explain your diagram

Key Words Topology Mesh Network Star Network WiFi Encryption Ethernet

Activity 1 You will be given some string and cups. Create a Mesh Network Create a Star Network Think about and discuss the features of each.

Activity 1 - Answer

Activity 1 - Answer

Content A Mesh Network is …. A Star Network ….. Where some or all of the workstations or other devices are connected directly to each of other. Most are usually connected to the node that they exchange the most data with.  A Star Network ….. In a star network, each device is connected by an individual cable directly to the server. Star networks are usually the layout of choice in schools and offices because they tend to be the most reliable of the topologies.

Activity 2 You will be given a selection of cards that show the advantages and disadvantage's of Wired and Wireless networks (Ethernet and WiFi) Sort the into groups Compare you answers with other students.

Activity 2 - Answer

WiFi WiFi is Wireless Frequency - radio waves are used to transmit data packets without the need for wires. This method is slower and more vulnerable to attack but it removes the need for cabling and networks This means that it can be set up in remote locations such as in vehicles, in parks or on planes etc.

WiFi Frequency and Channels https://www.youtube.com/watch?v=3YHovkP1JC8

Encryption Encryption is a method of scrambling data with a key code which makes no sense. On an open or public WiFi network anyone can join and sniff out packets of data from other users. Therefore encryption is used. If intercepted the data will have no meaning In order to read the data the user is required to decrypt the data using the key.

Content When you are using a secure site for example your bank, or purchasing on Amazon, encryption applied to keep your details safe: The encryption method used is called 'SSL' (Secure Socket Layer). A tiny padlock appears in your browser window, usally on the left hand side of the address bar and the website address starts with HTTPS://

Twitter example

Consider Twitter Twitter users a HTTPS when you log in, why? Why does the data need to be encrypted? What could happen if it was not encrypted?

Encryption video https://www.youtube.com/watch?v=w0QbnxKRD0w

Encryption task http://www.cryptoclub.org/

Encryption task http://www.cryptoclub.org/games/rogue_computer.php

Key Words Recap Topology Mesh Network Star Network WiFi Encryption Ethernet

Plenary Answer some questions from the exam papers on the topics Create a short animation or film on Network security. Stretch yourself! Code an encryption program using a programming language of your choice.

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