1.3 Computer Networks Flashcards
(35 cards)
Factors that affect the performance of networks
- Number of Users
- Amount of Bandwidth
- Wired or Wireless connection
How does the number of users affect network performance?
Having a lot of people using a network means lots of data is being transmitted which can slow it down.
Wireless Access Point (WAP)
A Wireless Access Point is a device that receives and transmits wireless signals on the network. Often connected to rest of the network by cables
What is bandwidth?
The amount of data that can be transferred in a given time. The grater the bandwidth, the better the network can perform.
How do wireless connections affect network performance?
Wireless performance depends on signal quality so is affected by the range of the device, the amount of interference from the other wireless networks, and physical obstruction like thick walls in buildings.
How does bandwidth affect network performance?
The more bandwidth, the more data that can be transferred at a time.
What hardware is needed to connect stand-alone computers to a LAN?
- WAPs
- Routers
- Switches
- NIC
- Transmission media
Routers
Routers are responsible for transmitting data between networks
Switches
Switches connect devices on a LAN. They receive data from one device and transmit this data to the device on the network with the correct MAC address.
Network Interface Card (NIC)
An internal piece of hardware that allows the device to connect to a network. They exist for both wired and wireless connection
Transmission Media
Transmission media carry data signals from one computer to another and are either wired or wireless. e.g. copper cables, fibre optic cables, wireless signals.
The Internet
The Internet is a global collection of interconnected networks. It is the biggest WAN.
Domain Name Server (DNS)
Translates websites’ domain name into its IP address
Hosting
When a business uses its servers to store files of another organisation
The Cloud
Data can be stored ‘in the cloud’. This means on servers run by big companies. The data remotely over the Internet.
What is a client?
A device which requests data from a server.
Web servers and clients
Servers provide services (e.g. Web server -> Web pages, File server -> file storage/retrieval). Clients request / use services from a server
Wired connection
Any physical connection made between two or more devices e.g. Copper wire, Ethernet cables, fibre optics etc.
Ethernet
Ethernet is a type of wired network media that allows data to be transferred between devices connected to both LANs (Local Area Network) and WANs (Wide Area Network. It is the most common type of wired connection within a LAN. Ethernet cables use copper wires to transfer data between devices.
Wireless
Any connection made between two or more devices which does not involve the need for a physical connection e.g. Wi-Fi, 4G, Bluetooth etc.
Wi-Fi
Wi-Fi is a means of allowing computers, smartphones, or other devices to connect to the Internet or communicate with one another wirelessly within a particular area. It has a range of about 100m, takes quite a lot of power (relatively), and has a high bandwidth (but less than a wired connection)
Bluetooth
Bluetooth is a standard for the short-range wireless interconnection of mobile phones, computers, and other electronic devices. It has a range of about 10m, takes very little power, and has a relatively low bandwidth
Wired vs Wireless
Wired: faster and more reliable, use Ethernet cables (twisted copper wire, coaxial or fibre optic)
Wireless: more convenient as you can move around while being connected, often cheaper as you need fewer wires, use radio waves to transmit data (Bluetooth or WiFi).
What is encryption?
When data (plain text) is translated into a code (cipher text) that only someone with the correct key can access. Protects communications from hackers
