Switching to VoIP

This is the Title of the Book, eMatter Edition

Copyright © 2007 O’Reilly & Associates, Inc. All rights reserved.

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Preface

Voice over IP is a family of technologies that has sweeping implications for every-

body who uses telephones, the Internet, fax machines, email, and the Web. VoIP

borrows from, and enhances, many disciplines of communications technology; it

promises to revolutionize the most familiar of these technologies, the telephone. The

Internet Protocol, analog telephony, digital telephony and T1 circuits, digital audio

signal processing, high-availability networking, and a host of other concerns are all

touched by growing borders of the vast, ambitious realm of VoIP.

VoIP has found its way into business phone systems, desktop messaging software,

and residential telephony service. Your mortgage or insurance company’s web site

may offer you the ability to communicate by VoIP with a customer service rep using

your computer. You may subscribe to VoIP-based telephone services like Packet8,

AT&T CallVantage, Vonage, or Broadvox Direct as a replacement for your old, tradi-

tional phone service.

In the late 1990s, VoIP was lauded as a way to save on long-distance charges by call-

ing Grandma and Grandpa using a PC with a headset and a microphone. But today’s

definition of VoIP is far broader. Hundreds of thousands of VoIP-based devices are in

use in the United States, and fast-growing shipments ...