1. Networking Objectives
Understand what the Internet is
Understand what hardware is needed to make the internet work
Modem
Router
LAN

2. Networking What is a network?
A computer network is where many computers are connected together. Networked computers can share files, offer services (such as ) and allow communication. The biggest network in the world is the internet!

3. Networking What is the Internet?
The internet is a interconnected collection of LAN’s. If a LAN is connected to the Internet that means that every computer in the LAN can access the internet. Conversely anyone on the Internet could access the public parts of the network.
The LAN’s will vary in size from very small (in the home) to very large (companies). LAN’s will also vary in what they make public.

4. Networking How LAN’s connect to the internet
Waingels
School LAN
ISP
Other
School LAN
ISP (internet service provider) allow people to connect to the internet. They tend to use a broadband connection to connect to the ISP.
ISP act as a gateway to the rest of the internet.

5. Networking Interconnected ISP’s
ISP’s are connected together to enable them to communicate. That way LAN 1 could communicate with Waingels.
Waingels
School
ISP
Other
LAN 1 BT
LAN 2

6. Networking Interconnected ISP’s
Request
LAN 1
LAN 2
Waingels
The request will travel through multiple networks before it gets to the destination. The further the packet has to go, the more networks it will go through.
School
ISP BT
Other
Awesome website
Talk talk
LAN 3

7. Packets could take different routes
Networking Choices
LAN 1
LAN 2
Waingels
Request
Request
School
ISP BT O2
Other
Awesome website
Talk talk
LAN 3
Packets could take different routes

8. Networking Traceroute
In the real world a packet will go through many different networks. It will be forwarded on by different routers. When a packet goes from one device to another we refer to it as a hop. The more hops a packet goes through the more devices it has gone through.
It is possible to see the route a packet travels by using a tool called traceroute.

9. Networking Traceroute
is a website which allows you to do a traceroute online. Below is the results of a traceroute for bbc.co.uk.

10. You can use any website you wish!
Networking Activity
Find some websites which ARE NOT based in the UK. Perform a traceroute and a lookup for that website.
You can use any website you wish!
Note – If the website stops working then use

11. Networking Routers role in creating the internet
A router allows multiple LAN’s to be connected together. Each port on the router will be connected to a separate LAN. When traffic arrives at the router it will then direct it towards the correct port. Routers will know what IP addresses it can reach and will use this knowledge to direct traffic. This information is stored in a routing table.
Routers allow packets to be sent along different routes depending on how busy each route is. Think of it like a taxi driver on our roads. If the taxi driver sees a traffic jam they will take a different route to the destination. Even if that route is longer! Routers do the exact same for packets.

12. Make notes on a routers role on the internet.
Networking Activity
Make notes on a routers role on the internet.
Read the following web page and update your notes with the information.

13. Wireless access point (WAP)
Networking Modem
Modem allows a network to connect to the internet over the phone lines. This is normally done using a broadband connection. ADSL (Asynchronous digital subscriber line) is the most common form of broadband in the UK. Data is prepared to go onto the phone network by a ADSL modem and is converted back at the ISP (internet service provider) end.
ADSL works differently from Ethernet as phone calls and data can travel down the line at the same time. The modem performs this conversion.
The common trend is to use an ADSL router to connect to the internet. These devices are multi-purpose devices and are not true routers. They do, however, provide routing features. They include
Wireless access point (WAP)
Ethernet connectivity (4 ports very common)
ADSL modem
Routing features
Firewall features

14. Place your bets! How fast is the school internet connection?
Networking Activity
Place your bets! How fast is the school internet connection?

15. Networking Digital Vs Analogue
Older modems used to convert data into a sound which could travel down a cable. Sound waves, which carry sound, can be drawn like the image below. Binary data is converted into a sound which is then transmitted down the phone line. Click the image to hear the sound!

16. Networking Converting digital to analogue
Data is converted to and from digital in order to travel over the phone network
Modem converts digital to analogue
Phone network
Modem converts analogue back to digital

17. Answer the following questions How fast is dial-up?
Networking Activity
Answer the following questions
How fast is dial-up?
What is the fastest internet connection available in the UK?
Which country has the fastest internet?
How fast is 3G internet? How fast is 4G?