This chapter discusses the key definitions and characteristics associated with establishing communications channels. It covers networking modes and switching modes, including the differences between routing and switching. It also covers the details of circuit switching and its particular applications, where it shines, and where it has fallen short in the past. This chapter also looks at packet switchingwhy it has become such a darling in recent years, what its potential prospects are, and what challenges it faces in the future. The chapter ends with a quick comparison between the public switched telephone network (PSTN) and the Internet.
Part I: Communications Fundamentals
Telecommunications Technology Fundamentals
Traditional Transmission Media
Establishing Communications Channels
The PSTN
Part II: Data Networking and the Internet
Data Communications Basics
Local Area Networking
Wide Area Networking
The Internet and IP Infrastructures
Part III: The New Generation of Networks
IP Services
Next-Generation Networks
Optical Networking
Broadband Access Alternatives
Part IV: Wireless Communications
Wireless Communications Basics
Wireless WANs
WMANs, WLANs, and WPANs
Emerging Wireless Applications
Glossary