1.2: The Reference Models
Read the introduction to section 2.2 and section 2.2.1, "The reference models," on pages 20-23. As you read, consider how we use layers as a model for describing network processing. Layers are the foundation for studying computer networks. You must understand how to work with layers to be able to describe the flow of a data request to its destination, and how the reverse occurs when the destination sends a response.