NetworkingBy Kyle Slinger

A network is where you can send information to and from different PCs

Networks

You can plug lots of PC’s into hubs and switches but there is a difference. Hubs send information from your PC to all the PCs on that network whereas switches just send information to individual PCs on the same network.

Hubs and switches

LAN is a small area of computers all connected together on the same network.

LAN

A lot of computers all connected together on the same network.

WAN

A server is a dedicated computer that stores all of the information off the PCs on that network.

With a proxy server you can get around security restrictions by using another IP that is not yours.

Servers

A cable that travels information at the speed of light.

Fibre Optic

◦ Everybody’s internet has there own unique IP address.

◦ IP addresses are typically made of four 8-bit numbers.

◦ They usually look something like this: 192.168.0.1

IP Address

A firewall is a filter that stops bad information coming into your PC. It has words that it looks for and if they try to come into your PC it will stop them.

Firewall

URL stands for acronym resource locator and is used to find things on the internet.

A Domain Name represents IP addresses because it is easier than remembering IP addresses.

URLs And Domain Names

WLANs are LANs which are spread over a wide area.

A PAN is a network of your personal devices e.g. phones and laptops.

WLANs And PANs

Networks are very important, especially in businesses for the following reasons:

File sharing Printer sharing Communication and collaboration Organisation Remote access

Why do you need a network

Disadvantages of networks

• They can be very expensive• Managing a large network is

complicated• If the server breaks down the

files become inaccessible unless you have a backup

• Viruses can spread through networks

• There is a danger of hacking.

You can get a firewall to stop malicious software etc. from getting to your PC.

You can use software like smooth wall which detects words and explicit images coming to a PC and stops them.

Make sure you log out.

Solving the issues

Intranet is a network of computer networks and computers using unique IP addressed ad TCP/IP protocol.

Internet

The WWW is a system of interlinked hypertext documents accesed via the internet

The World Wide Web

The intranet is a private computer network that used internet protocols

Intranet

Domain name servers are the equivalent of a phone book. They change domain names into IP addresses.

DNS

HTTP stands for Hypertext Transfer Protocol. HTTP is the foundation of data

communication in the world wide web. Hypertext is structures text that uses logical

links between nodes and containing text.

HTTP

URL is the generic term for all types of names and addresses that refer to objects on the world wide web.

The term web address is a synonym for a URL hat uses the HTTP/HTTPS protocol.

URL

URN stands for Uniform Resource Name. It is a string of characters used to identify the name of a web resource.

A URN looks something like a URL

URN

ISP stands for internet service provider. It is a company that provides you with access to the internet, usually for a fee.

ISP

In a peer to peer network all computers are equal. Every user is a network administrator and has to control there own machine. Access can be given to anyone else on the network you just give them a password.

A peer to peer network will often make use of a hub in order to connect the computers

Peer to peer

Client servers are the commonest network model in medium to large organisations.

One or more computers are designated as servers. These provide services to the rest of the machines on the network.

Client server

A bus network has a single backbone cable and all the devices are attached to it.

When a message is sent, it is divided into chunks and sent in both directions along the cable. All the computers on the network receive it.

Bus network

The devices are arranged in a circle. Each computer is responsible for passing the message on.

One way to implement a ring network is by token passing, with this a packet called a token passes from one computer to the next.

Token-ring network

This is the most common way to set up a network. All connections are to a central device such as a wiring cabinet with switches.

Installation of a star network is labour intensives the cable often has to go through walls and ceilings or under floors.

Star network