Unit 1.3 Networks Flashcards
Types of networks
LAN
WAN
What is a Local Area Network (LAN)
A Local Area Network covers a small geographical area located on a single site
What is all the hardware for a LAN owned by
All the hardware for a LAN is owned by the organisation using it
How are LANs wired
LANs are wired with UTP cable, fibre optic or wireless using Wi-Fi
What is a Wide Area Netowork
A Wide Area Network covers a large geographical area, connecting LANs together.
The infrastructure between LANs is leased from what?
The infrastructure between the LANs is leased from telecommunication companies who own and manage it.
How are WANs connected
WANs are connected with telephone lines, fibre optics cables or satellite links
Advantages of networking
Users can share files
Users can share peripherals: printers and connections to other networks, e.g. The Internet
Users can access their files from any computer on the network
Servers can control security, software updates and the backup of data.
Communication with other people, e.g. email and social networking
Disadvantages of networking
Increased security risks to data (as it is now shared)
Malware and viruses can spread very easily between computers (connected devices)
If a (central)server fails, the computers connected to it may not work (depending on the configuration)
The computers may run more slowly if there is a lot of data travelling on the network (and a lot of traffic on the network)
How are computers in a LAN connected
Computers in a Local Area Network (LAN) are connected with a switch
How are computers in a Wide Area Network connected
Computers in Wide Area Networks (WANs) are connected with a router
Factors that affect the performance of networks
Number of devices connected
Bandwidth
Transmission media
Latency/hardware limitations
Amount of traffic on the network
(Error rate)
What is bandwidth
The maximum amount of data that can be sent and received successfully in a given time
This is not a measure of how fast data travels, but how much data can be sent on the transmission media.
_______
e.g. water travelling through a straw and a drain pipe.
Water can travel at the same speed, through both, but bandwidth is much lower when water travels through the straw than drain pipe.
What is bandwidth measured in
Measured in bits per second, often called bit rate.
Explain how bandwidth affects the performance of networks
The greater the bandwidth, the more data can flow, even if data is travelling at the same speed