The TCP/IP Protocol Stack

The TCP/IP model (also called the Internet Protocol Suite) is the layered architecture that underpins all communication on the Internet. At A-Level you must know the four layers, their functions, the key protocols at each layer, and how data is encapsulated as it passes through the stack.

---

Why Use Layers?

Layered networking models break the complex task of communication into smaller, manageable sub-tasks. Benefits include:

• Modularity: Each layer can be developed and updated independently.
• Interoperability: Devices from different manufacturers can communicate as long as they follow the same protocols at each layer.
• Abstraction: Higher layers do not need to know the details of how lower layers work.
• Troubleshooting: Problems can be isolated to a specific layer.

---

The Four Layers