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Networks Nelson Rita-Madero Victoria - Coggle Diagram
Networks
Nelson Rita-Madero Victoria
Network concepts
Advantages:
It is easy to share files and data
It allows us to share resources
To communicate with users from another network
to store data centrally
to keep all of our settings centrally
What is a Network about?
It is at least 2 devices connected together so they can exchange data.
They allow: computers to share files, users to communicate each other through messages, and more.
Networks connection between computers
Cables: Wires.
Radio signals: Wireless, WI-FI.
Telephone lines: and modems
Satellite links
Disadvantages
The computer is vulnerable to hackers
Many tasks would become very difficult if the network breaks
Your computer is more exposed to a virus
Network devices
Network Cable
To connect different devices to make up a network, they are more secure and they can carry much more data.
Hub
It connects many computers together so they can make a LAN. It receives a message and sends it to every computer on the network.
Switch
Connects computers together to make a LAN.
It is more intelligent and specific than the Hub. It sends information to an specific computer.
Router
It connects together at least two networks.
It sends information to all of the computers.
Proxy Server
It is a computer set up to share a resource, like an Internet connection.
It says where the information has to go.
Bridge
It links one LAN to another one.
Firewall
It is placed between your computer and the rest of the network, and its function is to protect your computer from hackers.
Modem
It converts a digital signal into an analogue signal (modulates) for transmission over a telephone line. It also does the reversed process (demodulates).
It allows the computer to connect to networks over long distances using the telephone networks.
Types of Network
WAN
Wide Area Network:
A network that extends over a large area, links between computers that are over long distances, it is often created by joining several LANS together.
LAN
Local Area Network
: A network confined to one building or site, sometimes it can be a private network
MAN
Metropolitan area:
A network in a city or state
WLAN
Wireless Local Area Network
: A LAN that uses radio signals to connect computers instead of cables.
Network Topologies
Bus network
It has a long, central cable, ‘bus’, that is used to connect all of the computers together. Each computer has a short cable linking it to the ‘bus’.
Some characteristics
It stops working if there is a break in the central bus cable.
Can be slow since all computers share the same cable when communicating.
Is cheap to install (just one long cable).
Ring network
Each computer is connected to a loop of cable.
Can cope with a break in the ring cable since all computers are still joined together (it is now a bus network)
Star network
In this network, every computer is connected to a central device.This device passes messages between the computers.
At the centre of a star network, you might use a hub or a switch.
Hybrid network
It is the one that combines at least two of the basic topologies.
A network that has several star networks linked together is a hybrid network
Internet, Intranet, Extranet
Intranet
It is a private network that provides similar services to the internet.
"A computer network based on internet technology but designed to meet the internal needs for sharing information within a single organization or company."
For example
: e-mail, messaging, web pages.
Internet
It is a world-wide network.
It connects millions of organisations.
It provides the network connections that links computers together.
Ways of using this networks
View web pages on the WWW (World-Wide Web).
Sending and receiving e-mail messages.
Sharing files.
Communicating using voice and video.
Playing multi-player games.
Listening to streamed music or watching streamed video.
Extranet
Is a private network that uses the internet that allows people outside a business – partners, vendors or authorised customers – to access business information.
It is an extension of a business's intranet.