TCP and OSI Models
Computer Science: Edexcel IGCSE, topic 5.1.20
TCP and OSI Models
The four-layer Transmission Control Protocol model and the seven-layer Open Systems Interconnection models are two of the best known protocol layer models.
TCP model
- Application layer:
- Creates and interprets data (e.g. HTTP, IMAP, FTP).
- Transport layer:
- Splitting / joining of data (e.g. TCP).
- Internet layer:
- Adding addresses to data (e.g. IP).
- Network Access layer:
- Converting data into electrical signal (hardware) (e.g. Ethernet, WiFi).
OSI model
- The OSI model is a very similar protocol layer model.
- The OSI model has seven layers:
- Application.
- Presentation.
- Session.
- Transport.
- Network.
- Data Link.
- Physical.
Comparing the two models
- The two models describe the exact same network system:
- The first three layers of the OSI model are grouped into TCP's 'Application' layer.
- The 'Transport' layers are the same in both models.
- OSI's 'Network' layer is called 'Internet' in the TCP model.
- OSI's bottom two layers are combined into TCP's 'Network Access' layer.
Test yourself on TCP and OSI Models
Transmission Control Protocol Model
Open Systems Interconnection Model
What is the difference between the TCP and OSI models?