1. Networks
Topologies

2. Objective Understand the difference between LANs and WANs
Be able to give examples of each network
Know what extra hardware is required for a LAN to operate
Identify three different network topologies.

3. Stand alone Vs Networked
Why is it good to be part of a network?
What benefit does it give to the way we communicate? (Discuss)

4. Network Types
There are many different types of networks and they’re used in different situations. WAN (Wide Area Network) LAN (Local Area Network) Your teacher is going to show you a short video clip and you will need to make notes on a piece of paper or in a Word Document..

5. In Summary WAN LAN Covers a large area Covers small areas
Uses cable, telephone lines, satellites and radio waves to connect
Usually operate on a single site or within a single institution
Examples include: - Banks and the internet
Uses cables and radio waves to connect and includes examples such as: School or Home offices

6. Link here: https://vimeo.com/145982596
Topologies
A topology is the description of how the network is set up. It comments on the physical layout of the network. There are three network topologies which will be covered this lesson:
Bus
Ring
Star
Use the website and watch the 3 videos on Network Topologies. We’re going to act out how each topology works in a moment.
Link here:

7. Bus
Volunteers required:
Students stand in a row and hold hands in a line. This is the backbone of the network.
Other students will join the network as printers and other devices.
What would happen if one of the students in the backbone disconnects?
What would happen to the other devices?
What would happen if the printer failed?
What would happen if a computer failed?
To do this activity, you could have a note which students are required to pass around the network.
Advantages: - Cheap to set up / Failure of one node does not make the rest of the network crash.
You’re trying to get students to understand that if the computers fail along the backbone, that any other computers in this part of the network will crash and will not work anymore.
If other devices such as the printer crashed the rest of the network will be fine.
If a printer failed we would be ok because the backbone still allows communication, it would just mean that people couldn’t print.
If a computer failed it would just mean that other computers couldn’t communicate.

8. Star
Volunteers required:
Have one student in the middle. They’re going to be our HUB.
Have every other student put their hands on his/her shoulders.
This is a star network.
What would happen if the student in the middle failed?
This network uses way too much cable….. This can be expensive.
If the computer in the middle (the hub failed) then every computer on the network would fail. This means that you need to spend more on a hub! If the hub goes down, everything around it fails and it means that we can’t connect to each other.
You could get them to try and pass a note around.
Advantages: - Faster performance
Easy to install
Failure of one of the computers on the outside of the network don’t impact the rest of the network.

9. Ring:
Volunteers required:
Have students putting their hands on each others shoulders in a circle.
Explain how messages travel one way around the network. Students should pass a message to another computer.
Get one student to break from the network or fall down. What would happen to the message? Can it go back the other way?
The problem with this network is that the information can only travel in one direction.
If a computer breaks down, the information is travelling through each other. This means that when failing, the whole network fails. This is a problem and it means that the whole network goes down.

10. Activity
We’re going to create a poster which tells us about Network topologies, you may use the internet to help a little.
Choose the success criteria below: