Networks

ITGS syllabus sections 3.3 Networks and 3.4 Internet are covered in this chapter, examining LANs, MANs, and WANs, and different network architectures. Technical aspects such as MAC and IP addresses, protocols, domain names, and DNS are also covered in detail with clear diagrams and explanations. These resources can support students as they study the textbook:

Background Reading

IGCSE ICT clearly explains many networking topics through clear text and diagrams. Although it is not directly aimed at IB or ITGS level, it is still a very useful resource with a lot of relevant content and examples.

Networking components

This interactive Flash tool from GCSEComputing.org helps students learn the basic components of a network. The software can guide users through the creation of a network step by step, adding client computers, servers, hubs, and routers, or students can freely build and simulate their own network.
Network hub diagram Network switch diagram

Network components: Hubs, switches, and routers

ITGS students need to know the difference between network hubs, routers, and switches. These two diagrams show how hubs and switches broadcast data, and are from page 69 of the textbook (click for larger versions).

Network architecture: LANs and WANs

Diagram from the textbook, showing a Local Area Network (LAN), with a router providing a connection to a Wide Area Network (WAN) - in this case, the Internet (click for larger versions).
  Client server network diagram Thin client network diagram Peer to peer network diagram

Types of Network: Client-server, thin client, peer to peer

To the left are diagrams of a client / server network, a thin client network, and a peer-to-peer network from chapter 4 of the book (click for larger versions).

Types of network: Virtual Private Networks (VPN)

Diagram of a Virtual Private Network (VPN), showing how remote users can connect to their business' local area network securely through a public network. Taken from page 75 of the book (click for larger versions).

Communicating on a network: IP addresses

Diagram from the textbook showing a LAN and WAN, and how public and private IP addressing work.

The Internet Explained (video) also has a good overview of Internet routing and addressing.


IP address tools

Networking Tools

The following links may be helpful to improve understanding of the issues related to IP addresses on page 79 of the textbook. A common misunderstanding is that IP addresses are anonymous, but as these tools demonstrate, it is relatively easy to discover information about - and even the location of - the owners of IP addresses:

Internet backbone structure and data routing

Greg's Cable Map is a fantastic site with an up to date, interactive map of Internet backbone cables. Current and planned backbone cables can be displayed, and additional information such as landing sites is shown.

TeleGeography's submarine cable maps are simply amazing. Not only do they have a world map (left), but their map gallery contains interactive Internet backbone maps of Latin America, the Middle East, and the Asia Pacific region. Each features Internet connectivity statistics about the region's countries. The maps are available in high resolution versions which would look great on a classroom wall.

Finally, Many Possibilities has a regularly updated map of the submarine cables surrounding Africa.

These resources are great for helping students understand the nature of the Internet and how data is routed, which has implications for privacy, security, and reliability.

They can be used to supplement the information on page 80 of the book, and with articles such as Bangladesh suffers internet disruption after cut cable (BBC), Faulty cable blacks out internet for millions (Guardian), Ship's anchor slows down East African web connection (BBC), Syria: Internet and mobile communication 'cut off' (BBC), and Egypt arrests as undersea internet cable cut off Alexandria. The video The Internet Explained is also useful.

Development of the Internet

A useful networking resource is the BBC's The Growth of Broadband (top left) which shows the development of Internet backbone structure over the years - from 4 million broadband subscribers in 2009 to over 400  million in 2011.

Another interactive BBC map (bottom left) shows the global spread of Internet access, from relatively low rates of access in 1998 to much higher rates today.

Both maps make a great starting point for discussions about the spread of Internet technology and its effects on our lives. Equality of access issues are also clear here, and it is notable that even today there are large areas of the world few people have access. Internet World Stats is another site with up to date Internet use and penetration statistics.

Interactive cable map

Interactive map showing land and sea based fibre optic Internet cables in and around Africa. This data is mapped onto Google Earth using the KML data from the UbuntuNet Alliance.
Internet visualisations Malware map

 Internet Visualisations

Chris Harrison's Internet Maps site contains some stunning visualisations of the Internet, including the Internet's population density and city to city connections.

These resources would look great printed out large in the ITGS classroom and make great starting points for conversations about the global spread of technology and equality of access (the map to the left shows Internet connection density - North America and Europe can be clearly seen, while the coasts of South America and Africa are barely visible).

The map to the left was created in an unconventional way - by an anonymous researcher who hacked into nearly 500,000 computers in order to plot their location and produce the map data. The web site contains an animated version where Internet connection density can be clearly seen moving across the globe as the day progresses.

Classroom Resources: Networking posters

How the Internet works infographic

Diagram showing how the Internet works, covering protocols, IP addresses, Internet Service Providers, and many Internet-related statistics. Very useful as an overview of the processes that occur when you use the Internet. Would make a nice ITGS classroom poster.








History of the Internet infographic

Infographic showing the major developments in the history of the Internet, from 1962 to 2009. From this diagram it is very easy to see the rapid growth of the Internet in the last decade. Would make a nice ITGS classroom poster.

Starter / review exercise

Lesson resources: Keyword Bingo

Give students one or two cards containing ITGS key words, then read out the definitions. The first student to get all key words wins. This set of cards covers only key terms related to chapter 4 of the book, Networks. Download: Student cards, teacher clues.
Revision flashcards

Lesson resources: Revision Flashcards

Networks revision flashcards to test students on the key terms. The 'Learn' and 'Test' modes of Quizlet work best.
Taboo game

Lesson resources: Banned words game

Banned words game - This game is similar to 'Taboo' or 'Forbidden Words'. Each card contains an ITGS key networks term which students must explain to the class without mentioning the 'taboo' words listed on the card. The aim is to improve students' ability to explain key ITGS language and have a little bit of fun. Works well as a starter with the class split into two teams. I find printing the cards on coloured paper and laminating them works best.

Download Networks cards or the blank cards to make your own.