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Home , Router (computing)

The and hardware Teacher’s Notes

Lesson Plan

Length 60 mins Specification Link 216/j Units

Candidates should be able to: Learning objective (j) describe the hardware needed to connect to the internet including , routers

Time (min) Activity Further Notes

10 Using a projector, display the Interactive Starter Activity which describes the structure of the Internet and has a link to a video which shows how data is transmitted over the Internet between England and the USA.

10 Watch the set of videos, pausing to discuss the content.

5 Discuss the videos to assess learning. Ask questions such as: • What is the Internet? The Internet is a global system of inter- connected computer networks that use the standard network protocol, TCP/IP to serve several billion users worldwide.

It is a network of networks that consists of millions of private, public, academic, business, and government networks that are linked by electronic, and optical networking .

It modulates and demodulates the signals • What is the function of a ? that are sent from a computer or network over lines.

• What is the function of a network adaptor? A component that connects a computer to a . It formats the data sent from the computer into a required format according to the protocols (rules) of the network e.g. TCP/IP.

• What is the function of a router? A router is hardware device (or software program) that is designed to manage the paths along which information packets are forwarded within a network.

20 Worksheet 1 Pupils to complete Worksheet 1 either on paper or on Answers provided. computer. They may need access to the Internet to Ask students with the correct responses research some of the questions. to explain to the class how they arrived at Ask individual students for their answers and discuss their answers. with the class so that all students have the correct answers.

® Time (min) Activity Further Notes

10 The students use the Interactive Activity 1.

Extension Challenge/Homework Students to complete and submit Worksheet 2 for homework.

5 Plenary – Tracing the route Using a projector show a computer display. In Windows use the tracert command at the command prompt to show the number of ‘hops’ on the route to the World Science Festival website. http://www.cambridgegcsecomputing.org/weblink23)

On a Mac use the traceroute command in the terminal window. WORKSHEET 1 ANSWERS

1 (a) Explain what is meant by the Internet. The Internet is a global system of interconnected computer networks that use the standard network protocol, TCP/IP to serve billions of users worldwide. It is often called a ‘network of networks’ that consists of millions of private, public, academic, business, and government networks that are linked by different networking technologies. (b) What is the , or ‘web’? The WWW or W3 is one of many applications of the Internet and computer networks. It is a system of interlinked hypertext documents that can be accessed via the Internet. With a web browser users can view web pages that may contain text, images, videos, and other multimedia and navigate between them using hyperlinks. It was first proposed by the British scientist, Tim Berners-Lee in 1989 and he created the first website in 1990. He could be a billionaire if he had patented the idea but he chose to let anyone freely use his invention ‘for the good of mankind’.

In order to access the Internet, several items of hardware are required. 2 Explain the functions of the following items: (a) Network adaptors A network adaptor is a component that connects a computer to a network. It is also known as a network interface card or network interface controller (NIC). It formats the data sent from the computer into a required format according to the protocols (rules) of the network e.g. TCP/IP. Originally the adapters for desktop PCs were on ‘cards’ that were installed in the computer but are now built into the motherboard. Adapters that connected to USB ports were more commonly used in laptop computers. They now support both wired and Wi-Fi connections.

® WORKSHEET 1 ANSWERS

2 (b) Modems The word “modem” is short for modulator-demodulator. It is called this because it modulates and demodulates signals sent from and received by a computer over a network. They originally modulated the signal into an analogue form for transmission over traditional phone lines and then demodulated it back into a digital form for the computer. Wireless modems convert digital data into radio signals and back again. In digital communications networks e.g. fibre optic cable, the modem modulates the data into a signal that can be transmitted over the cable.

(c) Routers A router manages the paths along which information packets are sent within a network. Routers also forward data packets between networks. A router is connected to two or more data lines from different networks. When a data packet comes in one of the lines, the router reads the address information in the packet to determine its ultimate destination and sends it along a suitable route. A data packet is typically forwarded from one router to another until it reaches its destination and different packets of the same file may be sent along different routes 4 depending on those decided by the routers which take into account the overall network traffic. In a , routers connect the local computers with the ISP (Internet Service Provider).

® WORKSHEET 2 ANSWERS (a) The table below shows some statements about the Internet. 1 Tick one box in each row to show whether the statements are true or false. (3)

TRUE FALSE The Internet is a . Data travels across the internet in packets. The Internet is a network between many networks.

2 Describe what is meant by the World Wide Web (W3) and explain how it is different to the Internet. (4) The Internet is a or a ‘network of networks’ (1) whereas the WWW is one of the many applications running on it. (1) (Any two of) It consists of interlinked hypertext documents. (1) May contain text, images, videos, and other multimedia. (1) Can navigate between them using hyperlinks. (1)

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