This key facts covers Layer 3: Transport Layer within TCP/IP Layers for GCSE Computer Science. Revise TCP/IP Layers in 3.5 Fundamentals of Computer Networks for GCSE Computer Science with 16 exam-style questions and 18 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 4 of 11 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Layer 3: Transport Layer
What happens here: Ensures reliable data delivery between applications using TCP or UDP.
- Purpose: Reliable end-to-end communication and error checking
- Protocols: TCP (Transmission Control Protocol), UDP (User Datagram Protocol)
- TCP: Reliable - checks data arrived correctly, resends if lost
- UDP: Fast but unreliable - no error checking (used for streaming, gaming)
- Port numbers: Identifies which application to deliver data to (HTTP=80, HTTPS=443)
- Data format: Segments (TCP) or Datagrams (UDP)
Practice questions for TCP/IP Layers
How many layers does the TCP/IP model have?
Describe what the Internet layer does in the TCP/IP model.