|  | 2.2 | The OSI Reference Model
| 2.2.2 | The seven layers of the OSI reference model

The problem of moving information between computers is divided into seven smaller and more manageable problems in the OSI reference model. Each of the seven smaller problems is represented by its own layer in the model. The seven layers of the OSI reference model are:

> Layer 7: The application layer
> Layer 6: The presentation layer
> Layer 5: The session layer
> Layer 4: The transport layer
> Layer 3: The network layer
> Layer 2: The data link layer
> Layer 1: The physical layer

During the course of this semester, you will start your studies with Layer 1 and work your way through the OSI model, layer by layer. By working through the layers of the OSI reference model, you will understand how data packets travel through a network and what devices operate at each layer as data packets travel through them. As a result, you will understand how to troubleshoot network problems as they may occur during data packet flow. For more information about the OSI model, visit the following site:

| Web Links
| The OSI Seven Layers Model