This chapter works with the next six chapters to act as a foundation for the technology discussions that

follow. In this chapter, some fundamental concepts and terms used in the evolving language of

internetworking are addressed. In the same way that this book provides a foundation for understanding

modern networking, this chapter summarizes some common themes presented throughout the remainder

of this book. Topics include flow control, error checking, and multiplexing, but this chapter focuses

mainly on mapping the Open System Interconnection (OSI) model to networking/internetworking

functions, and also summarizing the general nature of addressing schemes within the context

of the OSI model. The OSI model represents the building blocks for internetworks. Understanding the

conceptual model helps you understand the complex pieces that make up an internetwork.