Lesson 6: The TCP/IP Model
The TCP/IP model is the practical protocol suite used on the Internet and modern networks. It is simpler than the OSI model, collapsing several layers.
The Four Layers of TCP/IP
| TCP/IP Layer | Corresponding OSI Layers | Focus |
|---|---|---|
| 4. Application | 7, 6, 5 (Application, Presentation, Session) | User applications, data formatting. |
| 3. Transport | 4 (Transport) | Segmenting, reliability (TCP) or speed (UDP). |
| 2. Internet | 3 (Network) | Logical addressing (IP) and routing. |
| 1. Network Access | 2, 1 (Data Link, Physical) | Physical addressing (MAC), cables, NICs. |
Key Difference
While the OSI model is excellent for teaching and troubleshooting (identifying which specific function is failing), the TCP/IP model is the practical implementation model.