1.3 Wireless networking Flashcards
What is a Wireless Access Point (WAP)?
A device that sends and receives data using radio signals
What is wireless networking?
-Data is broadcast at a chosen frequency.
-Frequencies are split into bands.
Almost all wifi uses 2.4 or 5Ghz.
-Bands are split into overlapping channels.
What is the 2.4Ghz Band?
-Greater range and coverage
-Very heavily populated, with more interference
What is the 5Ghz Band?
-Less crowded
-More non-overlapping channels
-Transmits faster
-Finds it hard to penetrate walls
What are WiFi Risks?
-Devices can be accessed without a physical connection
-Bandwidth can be stolen
-Data can be intercepted
What is a Layer?
A step in a protocol.
Why do we use layers?
-Each layer can be developed/tested separately
-Different people can work on different layers
-Layers can be improved and replaced
What are the 4 layers of the TCP/IP stack?
-Application layer
-Transport layer
-Internet layer
-Link layer
What happens at the application layer?
Select an appropriate protocol
What happens at the transport layer?
-Split data into packets
-Add the packet numbers and a port
What happens at the internet layer?
-Add the sender and recipient IP.
-Creates a socket.
What happens at the link layer?
-Add the sender and recipient MAC address.
What is a Domain Name System?
-A database matching IP addresses to domain names.
-DNS can prevent you from accessing sites.
What is a Uniform Resource Locator (URL) ?
The written address of a website.
What are key DNS characteristics?
-Speed
-Privacy
-Personalisation
