Chapter 2. The OSI Reference Model

Exam Objectives

• Describing the OSI reference model

• Describing the purpose and basic operation of each layer in the OSI reference model

• Describing the benefits of the OSI reference model

• Describing the purpose and basic operation of the protocols in the OSI and TCP/IP models

• Associating network devices to each layer in the OSI reference model

This chapter covers the Open Systems Interconnection (OSI) networking reference model. You discover the seven layers, their purpose, and how they relate to each other. The data encapsulation concept is also introduced.