Data Transmission

Question 1

Protocol

Answer 1

Set of rules defining a method of data communication

Question 2

3 data protocols

Answer 2

SMTP, POP3, IMAP

Question 3

SMTP

Answer 3

Simple Mail Transfer Protocol (SENDING)

Question 4

POP3

Answer 4

• Post Office Protocol 3 (RECIEVE)

- Only ever 1 copy

Question 5

IMAP

Answer 5

• Internet Message Access Protocol (RECIEVE)

- Leaves a copy on server

Question 6

Voice protocols

Answer 6

Allows voice calls between devices over internet

Question 7

Video calls

Answer 7

Video is compressed and encrypted

Question 8

Web pages (HTTP)

Answer 8

Hypertext Transfer Protocol

Question 9

Secure payment system

Answer 9

More than 300 in the world

Question 10

HTTPS more secure than HTTP, what safety features?

Answer 10

• SSL (Secure Sockets Layer)

- TLS (Transport Layer Security)

Question 11

NFC Payments

Answer 11

Transfer data between devices near each other

Question 12

3 Major NFC

Answer 12

• Samsung Pay
• Android Pay
• Apple Pay

Question 13

How is NFC safe

Answer 13

Biometrics, passwords, face recognition

Question 14

Bandwidth

Answer 14

Measured in Mbps, high bandwidth = more data per second

Question 15

Latency/Ping

Answer 15

Total time it takes for a packet of data to travel from source to destination

Question 16

Latency/Ping affecting factors

Answer 16

Distance, number of hops, traffic, type of connection, equipment delays

Question 17

Why is compression used

Answer 17

To reduce file size (lossy or lossless)

Question 18

Lossy

Answer 18

Data is lost, causes image to look bad (artefacts, weird patches of colour)

Question 19

Lossloss

Answer 19

No data is lost

Question 20

Codecs

Answer 20

Coder-Decoder

Question 21

Codec

Answer 21

Encodes data into a format that can be used to transmit it.

Question 22

Implications of codecs:

Answer 22

• Encoding/compressing takes time
• End user will need same codec to decode file
• Video & audio codecs need to work fast otherwise lag will be present