NETWORKS (2) Mr Conti Lesson 2

Learning Objectives  By the end of this presentation we will have learned:  what a network is  the advantages and disadvantages of networks  about the topology of networks  about different types of network.

Socrative Base Knowledge Room No:

Using school computers What rules are there about using school computers?  Each user must have a unique username and password.  Users must log on and log off each time they use a computer.  Users must choose a password that only they know, and remember it and keep it private. Why do these rules exist?  Because the computers are in a network.

What is a Network?  A network is a group of computers that are linked together. Each computer is connected (via a switch) to a server.  The server is a very powerful computer that provides programs and storage space for other computers.  When you use programs and save files on school computers, you are actually saving them on the server.  Networks are beneficial because software, storage, peripherals and processing power can be shared. What is your school computer network made up of?

Starter Task Think-Pair-Share  Today anyone who uses a computer, tablet, e- reader, smartphone or many other digital devices is likely to be connected to a network.  Networks differ in size. They may cover a room, house or office, or could even be global. Which devices have you used to connect to a network this week?

The Advantages of Networks  As with any form of technology, networks are only used when the advantages outweigh the disadvantages.  The main advantage of a network is that resources such as printers are shared. This means that each computer on the network does not need its own printer, and a user does not have to move to a different computer to print something. How is business 2 better organised than business 1? Business 1 Business 2

Answer  Business 2 saves money in comparison with business 1 because it doesn’t need to buy as many printers.  It also saves time as employees don’t have to keep moving around to use a printer.

Network cards In order for a computer to function as part of a network, it has to have a special piece of equipment called a network interface card (NIC) installed.  A NIC has a port for a network cable to be connected.  NICs are still very common, but increasingly people are using wireless network cards or wireless USB adaptors.

Wireless networks  It is possible to connect computers on a LAN without using wires. A wireless network card is similar to a standard NIC but has a transmitter/receiver for sending signals via radio waves.  Wireless networks are popular as they allow the user more freedom, such as working outside. Are there any disadvantages to using wireless networks?

Answer  Wireless networks can drop out due to interference. They may also be a lot slower at data transfer than wired networks. Wireless networks are also more susceptible to being accessed by unauthorised users. ‘Piggybacking’ is a term used to describe someone accessing a wireless network without authorisation.

Hubs

Routers

Switches

Describing Networks

Socrative Room No: Extension Task Consider different parts of your school buildings, or the places where you live, and discuss their suitability for wireless networks.