data transmission issues

Question 1

user authentication

Answer 1

• usernames and passwords authenticates users who have permission to use a network and prevents unauthorised access

Question 2

firewalls

Answer 2

• monitor traffic to prevent unauthorised access and dangerous data packets being passed into the system

Question 3

encryption

Answer 3

• data can be intercepted while being transmitted
• encryption ensures that intercepted data cant be read
• e.g. HTTPS

Question 4

VPN and security

Answer 4

• VPNs create a secure connection between remote sites and users over internet to prevent data being read

Question 5

Bandwidth and latency

Answer 5

• bandwidth; rate of data transfer over a network (bits per second)
• latency; time delay for a data packet to transfer to its destination (milliseconds)

Question 6

bandwidth and latency implications

Answer 6

• bandwidth is an important factor since it affects how long files take to download
• online gaming needs low latency because the gamer needs a fast response
• video calls need low latency and high bandwidth because you need to transfer a lot of data and a fast response

Question 7

compression

Answer 7

• it reduces file size so they can be transferred faster

- e.g. video and audio for VOIP calls

Question 8

compression; lossy and lossless

Answer 8

• lossy; data removed during compression is permanently deleted e.g. images, audio and video
• lossless; original data can be recovered when uncompressed e.g. document

Question 9

codecs

Answer 9

• a program used to compress and decompress video and audio file
• reduces the space they take up on disk and allow fast transfer
• leads to loss of quality