The world was introduced to fiber optics in the form of exuberant little table lamps that emitted tiny bursts of light from the ends of impossibly thin tubes. Few people knew that this technology was destined to be one of the building blocks of the Internet.

Section A begins the unit with a look at fiber-optic cable and other basic building blocks for networks of all types-from miniature LANs that connect two computers with a single cable to the gigantic expanse of the Internet.

Section B delves into the wildly popular topic of home networks. It provides background on LANs in general, and then explains basics of installing and using networks.

Section C focuses on the "stuff" that powers the Internet-the devices, connections, protocols, and technologies that make it possible to access Web sites, chat online, and participate in multiplayer online games.

Section D compares options for getting access to the Internet. If you want to cast off your slow dial-up connection and climb on the high-speed access bandwagon, this section helps you evaluate the options. The section ends with important information on securing your Internet connection-whether on a standalone computer or an entire LAN.

When you complete this unit, you should be able to:

Describe the characteristics of various networks, such as MANs, WANs, LANs, PANs, HomePLC, HomePNA, Ethernet, Wi-Fi, Token Ring, FDDI, client/server, and peerto-peer

Diagram Shannon's model of a communications network

List the types of cables and other links typically used for data communications networks

Make a list of network devices, explain the role of each one, and indicate whether they are typically used on the Internet or with LANs

Describe the role of communications protocols and list some protocols typically associated with the Internet and LANs

Explain the differences between permanent IP addresses, dynamic IP addresses, private IP addresses, and domain names

Briefly recount the history of the Internet

Draw a conceptual diagram illustrating the Internet backbone, NAPs, NSPs, routers, and ISPs

Explain when and why you might use Ping and Traceroute utilities

Explain the difference between packet switching and circuit switching technology

Describe the advantages and disadvantages of dial-up, cable modem, DSL, ISDN, T1, T3, and wireless Internet access

Explain when and why it is important to implement security measures, such as antivirus software, firewalls, and Network Address Translation