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Data Packets

Exam code: 2210
Written by: Ashika|Reviewed by: Caroline Carroll|Updated 2 July 2026

Data Packets

Data Packets

What are packets?

  • Packets are small 'chunks' of data that make up a larger piece of data that has been broken down by the TCP protocol so that it can be transmitted over the internet

  • TCP stands for Transmission Control Protocol and is used for organising data transmission over networks

  • Small 'chunks' of data are easier and quicker to route over the internet than big 'chunks' of data

    • Routing involves finding the most optimal path over a network

  • Data can include anything from text, images, audio, video, animations, etc, or any combination of these

What do packets contain?

  • A packet consists of:

Header

Payload

Trailer

Source IP address

Actual data being transported

Additional security information
(less common)

Destination IP address

End of packet notification

Packet number

(1 of 5 etc.)

  • To transmit the message “This is a message :)”over the internet, TCP might break the message down into 4 packets

Example packet structure
  • Each packet contains a:

    • source IP address

    • destination IP address

    • payload (the data)

    • a packet number

  • Error checks make sure that when a packet is received there is minimal or no corruption of the data

  • Corruption is where packet data is changed or lost in some way, or data is gained that originally was not in the packet

  • Read error detection methods for more detail on how data packets can be checked to ensure corruption is avoided/minimised

Data Packets · Revision Notes · Computer Science · StudyDeck