Learn how to handle legacy phone technologies when you move to VoIP

Overview Get a look at how you can seemlessly and cost-effectively migrate voice technologies and applications such as fax, voice mail, interactive voice response, surveillance systems, and others to VoIP.

This chapter from the O'Reilly book Switching to VoIP opens by explaining, "When first designed, landline phone service was intended to carry sound signals, and its uses as a carrier of data were years away from realization. It's ironic that the technology that predated the telephone was itself a data transport technology: the telegraph. This device carried encoded messages from terminal to terminal across the 19th-century equivalent of a peer-to-peer network.

A lifetime later, in the 1960s, sound-encoding devices emerged, and, very soon, computers were able to send data, represented as sound, across the telephone network. Those devices were modems, and later fax machines—the descendants of the telegraph. Modems, fax machines, voice mail systems, emergency 911 service, and a slew of other messaging tools evolved around the international telephone network.

Today voice and data networks converge and VoIP begins to replace Bell's brainchild.IP telephony has the same fundamental goal as legacy telephony: facilitate human interaction at a distance. But, since IP telephony goes about this goal differently, not all of the specialized devices that evolved around the old system work with the new one. Fax machines, modems, and voice mail systems aren't necessarily compatible with VoIP, because they grew into a mold that was shaped by the old network.

In this chapter, we'll cover some of the great legacy technologies we've come to rely on and discuss ways of migrating their functionality to the converged network."

Published: June 2005
Authors: Theodore Wallingford
Chapter: Chapter 14: Traditional Apps on the Converged Network
Published by O'Reilly