The InternetWhat is the Internet and what are packets, routers and IP addresses?

Find out more in this presentation.

What is the Internet?

• The Internet is a global network that connects billions of computers around the world and is like a postal service where data can be sent to other computers.

• However, the World Wide Web is not the same thing. The WWW is a network of websites being linked together using hyperlinks.

• It has become a necessity in today’s society with the Internet and World Wide Web being used for education, business, shopping, connecting with other people and pleasure. In 2012, almost 1/3 of the world’s population had access to the Internet.

• The Internet was invented in 1969 by the US Department of Defence to allow soldiers to connect with each other in emergencies.

IP Addresses• An IP address stands for Internet Protocol

Address and is a unique set of numbers that identifies a computer, web site or server.

• There are 2 versions of IP addresses: IPv4 and IPv6. The most common is the IPv4 and uses 32 binary digits, split in into octets and is usually 4 numbers separated by dots, for example 2.30.107.55.

• An IP address is like an address to a door so other computers can send data to the right address.

• The are static and dynamic IP addresses. Static are permanent and are good if you want to make it easy for other computers to locate you but dynamic are more common and are temporary and are given by your Internet Service Provider.

Domain Names• A domain name represents one or more IP

addresses and is usually the name of the website, for example google.com or microsoft.com.

• Every computer or server has a Domain Name System (DNS) to translate Domain Names into IP Addresses and vice versa.

• We have domain names because it is easier to remember rather than a group of numbers.

• The link between domain names and IP addresses is that a domain name is what people type to get to an web address and an IP address is the name of the web address.

• Every domain name has a suffix which tells us which Top Level Domain it belongs to. Some are countries such as co.uk or .es.

• Others include .org for an organisation or .edu for Higher Education.

What is Packet Switching? 1• A data packet, or network packet, is data

which has been split up into packets which are then sent to a destination computer. It contains the data itself, where it is going to and where it has come from.

• Packet Switching is splitting data up into small packets and helping it arrive at its destination.

• When it leaves a computer, it goes through the network and will head off in different directions, taking the least busy route with the help of a Router.

• During the course of its journey, it will go through many routers, often in many different countries. Also, if one route is broken, it is automatically routed onto another route.

What is Packet Switching? 2• When the packets reach their destination, they are

put back together in the correct order. This is made easier because when the packets were being split up, they were each given a number.

• If a packet doesn’t reach the destination, a message is sent back to the sender for a replacement packet.

• However, some packets can get lost on its journey and will jump from router to router and to make sure it doesn’t disrupt the network, there is a ‘Hop’ Count to each packet so it can only jump from router to router a set number of times before it is deleted.

• The advantage of packet switching is that it is very efficient and one broken route won’t affect the entire network.

• However, the disadvantage of a packet is that small data items aren’t good and it takes time for the packet switching to happen.

Routers• A router is a device that transfers data from

one network to another network and to its destination using the quickest route.

• A router is found at a gateway where two or more networks connect.

• A router has a micro-computer inside that contains a list of all the networks it is connected to and how busy the network is.

• When a data packet reaches a router, it will find out where the packet needs to go, looks up all the networks available to go to that destination, checks how busy all the available networks are and send the packet along the fastest network.

• Also, routers are needed for a computer to connect to the Internet so that it can send and receive packets.

Routers in action

To track which routers and how many hops it took, type ‘cmd’ into the ‘Search Programs and Files’ section. This is the trace route for www.amazon.com and you can see on hop 8 and 9, the router was in London and on hops 10,11 and 12, the router was in New York. It took 30 hops in total.

References and Sources• What is the Internet?• http://www.bbc.co.uk/webwise/guides/what-is-the-internet• http://www.gcflearnfree.org/internet101/1 - This websites has lots of information on what the Internet is in a simple and

understandable way so that’s why I think this is a good website.

• IP Addresses• http://whatismyipaddress.com/ip-address• http://computer.howstuffworks.com/internet/basics/question549.htm - This website goes into detail in its information but

presents it in an understandable way.

• Domain Names• http://www.webopedia.com/TERM/D/domain_name.html - Easy to understand definition of Domain Names• http://www.cyberindian.com/domain-registration/article.php?article_id=72• http://en.wikipedia.org/wiki/List_of_Internet_top-level_domains - Includes a long list of different TLDs

• What is Packet Switching?• http://www.teach-ict.com/glossary/D/data_packet.htm• http://www.teach-ict.com/technology_explained/packet_switching/packet_switching.html - This website goes into a lot of

detail but in a child-friendly way so school children can understand what has been written.

• Routers and Routers in Action• http://www.webopedia.com/TERM/R/router.html• http://www.teach-ict.com/gcse_new/networks/hardware/miniweb/pg4.htm# - This is the same website as the packet

switching and is really good because it is easy to understand. • http://www.wikihow.com/Traceroute