Lesson 7 – How does the Internet work

The internet is simply a worldwide network that uses standardised communication protocols to transmit and exchange data.  Before we start to look at the internet take a look at the following image gallery to details interesting facts about the internet

Having spent time looking at the infographics above; as you will appreciate the internet presents not only a new way to look at and retrieve information from around the world but it also – you guessed it! –  presents us with a completely new vocabulary that we need to learn.

How Internet Infrastructure Works
One of the greatest things about the Internet is that nobody really owns it. It is a global collection of networks, both big and small. These networks connect together in many different ways to form the single entity that we know as the Internet. In fact, the very name comes from this idea of interconnected networks.
Internet Protocol (IP)
The protocol used to route packets of information across the internet.  A packet is an individual unit of data that is carried across a network, including the internet.  It is made up of a header which identifies the packet and a body which is the actual data message.  It is one of the functions of the Transmission Control Protocol (TCP) to organise an internet message into packets.
IP Address
Each computer on a network has an IP address which helps to identify it.
  • IP stands for Internet Protocol, which means the rules that networks have agreed to so that they can communicate easily with each other.
  • There are two versions: IPv4 and IPv6.  All computers connected to the internet use IPv4 and a few are now using IPv6.
  • The IPv4 address contains 4 groups of numbers separated by dots.

Task – Open up a web browser and type the following into the URL address line:

  • An IP address should be unique over a network and in a LAN no two nodes should have the same IP Address as this will cause problems with sending data to the correct work station or peripheral.
  • As there are so many computers on the internet, it is possible that two computers on the internet may have the same IP address.
  • For this reason more and more computers are now moving over to IPv6 which allows a greater number of computers to have a unique IP address.

Tracing the route of information

The graphic below shows a  simplified illustration of a web page request being made from your ‘client’ or Personal Computer (PC) for a web page on “Howstuffworks” server.  The request for information is channelled through routers and servers.  Note that the pathway to and from the server is not always the same each time.

Network router pathway

The internet offers tools to visually trace communication requests on the internet often referred to as traceroute tools.

Task – Investigate at least one of the traceroute tools below and see if you can track the route you use when accessing your favourite websites?

  1. http://visualroute.visualware.com/
  2. http://www.yougetsignal.com/tools/visual-tracert/
  3. http://traceroute.monitis.com/

Task – Complete the following task sheet:
Unit 1 – Lesson 7_The_Internet – task sheet