Wired and Wireless Networks Flashcards
What is a network?
Two or more computing devices connected together in order to share resources
What is a Local Area Network?
Two or more computing devices that are connected together in a close geographical area
What is a Wide Area Network?
Connects two or more LANs that are in different geographical locations
What is a node?
Any device that can connect to a network
What is a workstation?
A computer that is part of a network
What do devices on a LAN usually connect with?
Ethernet cables or Wi-Fi
Give three reasons why networks are commonly used
- Resources and files can be shared by users on a network
- Users can log on to any workstation on the network and still access their files
- Backups of files and documents can be made centrally rather than backing up each machine individually
Give three downsides of using computer networks
- They are expensive to set up and maintain as they need expensive copper cables and/or Wi-Fi to connect the nodes together
- If their is a problem with the central file server then no one will be able to access their files
- Viruses and malware can quickly spread throughout the network if security measures are insufficient
Name three different methods of connecting WANs
Fibre optic cables, satellite communication links and microwave links
Give three reasons why WANs are commonly used
- They enable LANs to connect to one another
- They allow workers to collaborate even if they are in different geographical location
- They allow files and data to be shared between LANs
Give two downsides of using WANs
- It is expensive to hire a WAN service from a telecom operator
- If there is a failure, it can be more difficult to solve the issue as the company itself does not own all parts of the WAN
What is network performance?
How well data is transmitted through the network
What is bit rate?
How the speed of the network is measured
What is bandwidth?
The amount of data that can be transferred over a connection in a given period of time
What is contention ratio?
The ratio of number of users compared to the bandwidth available
What is transmission media?
The technologies used to carry data around a network
What is error rate?
How many errors in the transmission of data occur over a given period of time
What is latency?
The amount of time it takes for a packet of data to travel across the network
What is a high latency network?
A network with long or significant delays
What are the five factors which affect the performance of a network?
Bandwidth, latency, error rate, transmission media and the number of users on the network
How does a Wi-Fi network makes use of frequency bands and channels?
Wi-Fi works in two frequency bands, one at 2.4GHz and the other at 5GHz. These are further divided into channels.
Why are separate channels a good idea for Wi-Fi networks?
Separate channels help to reduce the interference caused by other nearby devices
What are the four factors which might affect the performance of a Wi-Fi network?
Radio interference, physical obstacles, distance, channel availability
What is architecture?
The layout of a network, or how a network is organised
What is a client server network?
A type of network managed by a server which takes requests from client devices
What is a server?
A specialist computer on a network which provides services for other devices eg. file storage, web pages and printer access
What is authentication?
Using a network ID and password to check the authenticity of a user who is attempting to log into a network
What is a shared drive/area?
A file storage area on a network server where users can access files and resources