Data transmission Flashcards
What are the parts of a data packet?
Packet header
Payload
Trailer
What does the packet header contain?
Destination IP address
Sender’s IP address
Packet number
What are the steps of packet switching?
- Data is broken into packets and given a sequence number
- Each packet will take a different route to the next depending on the quickest route
- The router controls the route that the packet takes
- When packets arrive, they are reordered based on their packet number
What is serial transmission?
Data bits are sent one at a time down one cable at high speeds
What is serial transmission used in?
USB
What are the disadvantages of serial transmission?
Lower transmission speeds
What are the advantages of serial transmission?
Lower interference
More reliable over long distances
Smaller, cheaper connections to produce
What are the advantages of USB?
Backwards compatible
Cannot be inserted upside down
Do not need an additional power source ~ 5V power
Industry standard
What are the disadvantages of USB?
Only supports cable lengths of 5m
Slower data transfer speeds
Limitations of backwards-compatability
What is parallel transmission?
Several bits of data sent simultaneously across several wires
What is parallel transmission used for?
Printer cables or internal device connections
Disadvantages of Parallel transmission?
Data corruption commonly occurs over long distances
Skewing
Can only be used for short distances
What is skewing?
When data bits travel parallel to each other can move at different speeds causing them to arrive out of sync
Advantages of Parallel transmission?
Very fast data transfer
Can send data in both directions at the same time
What is simplex transmission?
Data travels only in one direction down a single cable
What is an example of simplex transmission?
Sending data from the computer to a monitor as it never needs to go the other way
What is half-duplex transmission?
Data can travel in both directions along a single cable, but not simultaneously
What is an example of half-duplex transmission?
Printer parallel cables
Text is sent to a printer, and the printer can send ‘Out of paper’ messages back; but only when the computer has finished sending text
What is duplex transmission?
Data can travel in both directions simultaneously using two communication channels
What is an example of duplex transmission?
Networking or Internet cables to transmit and receive at the same time
