Chapter Overview

The Internet is a worldwide interconnection of computers by means of many complex networks. The Internet was established in the late 1960s under the sponsorship of the Department of Defense and later through the National Science Foundation. It provided a way for universities and companies doing military and government research to communicate and to share computer files and software. In the early 1990s, the Internet was privatized and opened to anyone. Today it is a system with hundreds of millions of users across the world.

This chapter discusses the technology used in transporting data in packets through large numbers of computers called servers and Internet appliances called routers and the extensive fiber-optic Internet backbone. Technologies such as Frame Relay, asynchronous transfer mode (ATM), and SONET are discussed. The transmission protocol TCP/IP is discussed and the operation of a router is explained. This chapter also includes an introduction to storage-area networks (SANs). Finally, the subject of Internet data security is defined, and methods of encryption and authentication are considered.

Chapter Outline

15-1 Internet Applications
15-2 Internet Transmission Systems
15-3 Storage-Area Networks
15-4 Internet Security

Chapter Objectives

• Define the Internet.
• List the main applications of the Internet.
• Explain how data is transmitted over the Internet.
• Name and explain the three main types of transmission systems used in the Internet including ATM, SONET, and Frame Relay.
• Explain the details of the TCP/IP protocol.
• Explain the operation of a router.
• Identify and explain the major types of storage-area networks and their transmission technologies including Fibre Channel and iSCSI.
• Name the main types of security systems used with the Internet.
• Name the most commonly used encryption systems on the Internet.