Topic 2 - Data transmission

Question 1

What’s data?

Answer 1

information that has been translated into a form that is efficient for
movement or processing

Question 2

Movement/Transmission

Answer 2

From one device to another device

Question 3

Processing

Answer 3

generate meaningful information

Question 4

In what number system data is converted and transferred?

Answer 4

binary

Question 5

Data packet (datagrams)

Answer 5

small segment of large data
It consists of a header + payload + trailer

It is when data(sent over long distances) is split into smaller groups of bytes (for transmission over a network)
usually small, typically 64KiB = 524,288 bits

Question 6

Data packets advantage

Answer 6

Small packets are easier to control than a long continuous stream of data

• Error checking: only the packet that has error is asked to be resent. (delay and unnecessary use of resources X)
  -Large messages would need more time to be sent over a channel

Question 7

Process of data transmission simply

Answer 7

Original message -> converted to binary -> arranged and sent as packets

Question 8

packet structure (3 main components)

Answer 8

1. Header
2. Payload
3. Trailer

Question 9

Header

Answer 9

consists of:
1. IP of source device (sender)
2. IP of destination device (receiver)
3. Sequence No. (allows reassembly in correct order)
4. Size of packet in bytes (to ensure all packets arrived intact)
- often also the value indicating total no. of packets

Question 10

Payload

Answer 10

actual data in packet (about 64 KiB)

Question 11

Trailer

Answer 11

consists of:
1. method of identifying end of the packet (so packets can be separated from each other)
2. error checking (so packet arrives error free)