TCP &. OSI Models
Computer Science: OCR A Level, topic 3.3.11
TCP and OSI Models
The four-layer Transmission Control Protocol model and the seven-layer Open Systems Interconnection model 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 &. OSI Models
Transmission Control Protocol Model
Open Systems Interconnection Model
What is the difference between the TCP and OSI models?