3.2 Data Transmission Flashcards
What a Protocols?
Set of rules for data communication over a network. It defines the format and the order of messages exchanged between two or more things, and their actions.
What happens if there are no protocols?
Without them no info can be transmitted.
What do they protocols ensure [5]
- Ensure data integrity.
- Manage flow control.
- Prevent deadlock. -
- Manage congestion.
- Perform error checking.
What is deadlock?
two nodes trying to transmit at same time causing neither to work.
What is a Data packet?
A packet is a unit of data that s routed between an origin and a destination.
What is packet switching?
Packet switching, where packets are routed through a network.
Why do connection speeds vary? [5]
- The more network traffic the slower data transfer will be.
- Time of day.
- Distance
- Infrastructure - e.g. storm.
- Speed variance due to temperature, interference and type of file.
What is Data compression?
And why do we do it?
It is when you compress information into fewer bits. We do it in order to save time, sot that data can travel quicker.
What does data compression allow? [4]
- Allows backups and archiving.
- File transfer is easier.
- Media file transfer over web (some don’t allow over certain size)
- Encryption/protection.
What does data compression allow? [4]
- Allows backups and archiving.
- File transfer is easier.
- Media file transfer over web (some don’t allow over certain size)
- Encryption/protection.
What are the two types of compression?
Lossless - compressed and all restored.
Lossy - compressed and some lost, but lets it be smaller.
How do we compare different types of media? [4]
- Secuirty
- Reliability
- Cost
- Speed
