What is a computer network?
A computer network is a number of computers linked together to allow them to share resources. Networked computers can share hardware, software and data.
–BBC Bitesize
What are three advantages of networking computers?
- It is easy to share documents. Different users are able to work on the same document at once.
- Only one internet connection is required as it can be shared between every device connected to the network.
- Computers can share devices (e.g. printers / scanners)
- Centralised backups can be carried out automatically.
- Easier to install software over a network than on each individual computer
- Software updates / patches can be automatically pushed out by the server to ensure that all devices are up to date.
- Users can log in to any machine connected to the LAN as accounts are stored centrally on the server.
What does WAN stand for?
Wide Area Network.
What does LAN stand for?
Local Area Network.
What is a Local Area Network
A number of computers / devices linked together to allow them to share resources over a small geographical area
Define what a Wide Area Network (WAN) is
- A WAN connects LANS in different geogrphical areas.
- The communication medium is not owned by the company
- A company usually hires the network infrastructure
What is the definition of ‘bandwidth’?
Bandwidth is the amount of data that can be transmitted
…in a given period of time.
What does the acronym mbps stand for?
Megabits Per Second.
How does bandwidth impact on the performance of a network in relation to the speed of the network?
The amount of available bandwidth has a major impact on the performance of a network. The larger the amount of available bandwidth that is available the more data that can be transmitted in a given period of time.
How does bandwidth impact on the performance of a network in relation to the type of media being accessed?
Where large media files are being streamed the amount of available bandwidth is particularly important.
Should a number of users be watching streaming HD content demand on bandwidth will be high.
If there is insufficient bandwidth this could result in a reduction of quality in the video.
How does bandwidth impact on the performance of a network in relation to the number of users
If there are a large number of users on the network the amount of bandwidth available to each user may be limited. This will result in data being transmitted at a slower rate which will slow down the performance of the network.
What are the differences between a LAN and a WAN?
A LAN covers a small geographical area whereas a WAN covers a wide geographical area.
All of the telecommunications equipment used in a LAN is owned by the organisation whereas a telecommunications company provides infrastructure for a WAN.
What is meant by the term ‘client server network’?
- All devices are connected to a central server.
- The central server receives and processes requests from ‘clients’.
- The server stores user account details and files.
What is a peer network?
- All computers have equal status
- Each device can act as a client and a server
- All devices can request and provide network services
- No additional hardware / software needed to set up this type of network
What are the differences in how a client-server network and a peer network save files?
Client-Server:
- All files can be stored centrally
- Workers can access files from any computer
- All computers can update central databases
Peer-Peer:
- Files are stored on their own computers
- Users have to log-in to the same computer every time
What are the differences in how a client-server network and a peer network back-up data?
Client-Server
- Backups are easily managed as these can be done centrally from the File Server
- All data is backed up in one go
- Individual computers do not need to be backed up
Peer-Peer
- All computers are responsible for backing up their own files
What are the differences in how a client-server network and a peer network deal with security?
Client-Server
- Centralised security
- Antivirus and firewall can be installed and configured from a central location
Peer-Peer
- Individual security may need to be installed on individual machines
What environments is a client-server network and a peer network most suitable for?
Peer-Peer is appropriate for a small number of computers and a low traffic environment
Client-server is useful for if there are lots of computers and it will be a high traffic environment.
Describe two reasons a business might choose a peer network model.
- All devices have equal status, there is no central server which makes them relatively easy to maintain.
- There is no dependence on the server. If one device fails only the information stored on that device will be inaccessible. The network will still operate without that node.
- They are relatively easy to set up without the need for a network manager.
What hardware is required to set up a network?
- Wireless access point (WAP)
- Router
- Switch
- Network interface card (NIC)
- Transmission media (e.g. ethernet cable)
- Modem
What is the purpose of a Wireless Access Point (WAP)?
Allows for wireless devices to connect to a network (either LAN or WAN)
What is the purpose of a router?
To transmit data between at least two different networks.
What does a Switch do in a network?
A switch is an interconnection device that connects two or more devices together and helps in solving the issue of data collisions
What is a data collision?
When two or more computers place a packet onto a network at the same time
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Wired & Wireless Networks47
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Network Topologies, protocols and layers25
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System Architecture - Components of the CPU & The Fetch Decode Execute Cycle22
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System Architecture - The performance of the CPU28
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System Architecture - Computer Systems18
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Data Representation - Images19
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Data Representation - Sound28
