Introduction

One of the most important networking concepts to understand is the Open Systems Interconnect (OSI) reference model. This conceptual model, created by the International Organization for Standardization (ISO) in 1978 and revised in 1984, describes a network architecture that allows data to be passed between computer systems.

This chapter takes a detailed look at the OSI model and describes how it relates to real-world networking. It also examines how common network devices relate to the OSI model.