Communication and the Internet Flashcards
What is a computer network?
A computer network is a group of connected systems and other devices linked together so that they can communicate and share resources such as printers.
How small can networks be?
They can be as small as two computers and a printer in a home network.
What does LAN stand for?
LAN stands for Local Area Network.
How does LAN work?
It is a network in a small geographical area, that is usually managed by a local manager or a team at the site.
What does WAN stand for?
WAN stands for Wide Area Network.
How does WAN work?
They connect separate LANs over a large geographical area to form a network of networks.
Why do large companies share LAN?
In order to share resources and data.
What can computers in a WAN do?
They can communicate with computers and users in other locations.
How are WANs managed?
It is managed by several different people or parts of an organisation working together (collective ownership).
What is the meaning of bits per second?
The speed that data can be transmitted through a communications medium.
What is the file server in a client-server network?
Computers which control access and manage the network.
What is the client workstation in a client server network?
Computers which allow users to run applications and to access the server and also network resources, such as printers.
What is the difference between client-server networks and peer-to-peer networks?
Client-server networks have two types of computer whereas peer-to-peer networks have only one type of computer.
Is there a server in a peer-to-peer network?
There is no server to manage the network, all the computers are connected together equally.
How do the computers work in a peer-to-peer network?
They are all equal and can communicate with each other directly without having to go through a server.
How do clients connect to servers in a client-server network?
They use their network addresses to access their services, programs and data stored on them.
What do the servers do once the client has attempted to connect to it in a client-server network?
The servers obtain the address of the client and send the requested data and services.
How are servers responsible for network security in a client-server network?
They allocate login names and passwords to users.
Where are the files held in a client-server network?
All files are held on the servers and can be backed up centrally.
In a peer-to-peer network, what can each client act as?
They can act as a server, other clients can share programs, data and printers.
How is security distributed in a peer-to-peer network?
Each user can grant rights to others and allocate passwords.
Where is data stored in a peer-to-peer network?
It is stored on each client and not centrally.
What is each user responsible for in a peer-to-peer network?
They are responsible for backing up each client.
How are devices physically connected?
Using either copper wire or fibre-optic cable.
How does copper wire transmit data?
Data is transmitted as electric signals.
How does fibre optic cable transmit data?
Data is transmitted as pulses of light.
What is an advantage of copper wire?
It is cheaper than fibre optic.
What is an advantage of fibre optic cable?
Transmits signals at faster speeds over greater distances than copper wire.
What do wireless networks use to communicate?
They use radio waves.
What are the most commonly used frequencies for data transmission in wireless networks?
2.4 GHz and 5 GHz.
How many cycles per second is 1 GHz equal to?
1 GHz = 10^9 cycles per second.
What is bandwidth?
Bandwidth is the amount of data that can be transmitted per second.
What is bandwidth measured in?
It is measured in bits per second.
What are the bandwidths of the wired and wireless networks?
Copper cable - 1 Gbps
Fibre-optic - 10 Gbps
Wireless - 600 Mbps
What are protocols?
Protocols are the rules that computers must be follow when communicating over a network.
What is the difference in installation between cable and wireless?
Cable - difficult as cables must run throughout the site
Wireless - easy - just need WAPs
What is the difference in cost between cable and wireless?
Cable - expensive as the cost of cables and installation
Wireless - cheap - only cost is WAPs
