Network+ Training Guide

Chapter 4. The OSI Model

OBJECTIVES

This chapter covers the following CompTIA-specified objectives for the “Protocols and Standards” section of the Network+ exam:

Identify the seven layers of the OSI model and their functions.

• The OSI reference model provides a theoretical framework that is used to describe the processes and technologies associated with networking.

Identify the OSI layers at which various network components operate including:

• Hubs

• Switches

• Bridges

• Routers

• Network interface cards (NICs)

• Understanding how devices' functions relate to the OSI model can provide a greater understanding of networking principles.

OUTLINE

Introduction

Why Do We Need a Network Model?

OSI Reference Model 101

Layer 1: The Physical Layer

Layer 2: The Data-Link Layer ...