Unit 1: Page 20: Data Transmission Issues Flashcards
What is data transmission?
It’s an important part of computer use. It involves sending digital messages between devices in a network, such as in a LAN or over the Internet.
List three security considerations associated with data transmission.
> User Autentication
Firewalls
Encryption
Describe how user authentication is associated with data transmission.
> Usernames and passwords authenticate users who have permission to use a network and prevent unauthorised access by hackers.
Describe how firewalls are associated with data transmission.
These monitor traffic to prevent unauthorised access and dangeroud data packets being passed into the system and causing harm.
Describe how encryption is associated with data transmission.
Information can be intercepted while being transmitted. Using encryption rnsures intercepted data cannot be read. HTTPS is a commonly used method for secure data transmission.
Explain the link between VPN and security.
VPNs create a secure connection between remote sites and users over the internet to prevent data being intercepted and read.
Draw a VPN diagram.
What is bandwidth?
Bandwidth is the rate of data transfer over a network, usually measuring in bits per second.
What is latency?
latency is the time delay for a data packet to transfer to its destination, usually measured in milliseconds.
Explain three implicaions with bandwidth and latency.
> Browsing the internet doesn’t need an instant response so latency isn’t a big factor. Bandwidth is an important factor as it affects how long files take to download.
Online gaming needs very low latency as players need a fast response for real - time updates of character movement, etc.
Video calls need low latency and high bandwidth as you need to transfer a lot of data (video and audio), but you also want a fast response to avoid stutter.
Explain what compression is.
Compression reduces file size so files can be transferred faster.
What is lossy compression?
Data removed during compression is permanently deleted. Commonly used in images, audio and video.
What is lossless compression?
All original data can be recovered when uncompressed. commonly used for documents
Explain what a codec is.
A codec is a program used to compress and decompress video and audio files. This reduces the space they take up on disk (HDD) and allows fast transfer over a network, such as the internet, for VOIP calls and online streaming.
> This leads to a loss of quality in the video or audio - in resolution, frames per second or both.
