Traditional Telephony

While long considered two separate and distinct areas of focus, telephony and data networking today tend to have more in common that not. While the explosive growth of the Internet has done much to blur the lines between network data and voice traffic, you still need to be familiar with the basic concepts surrounding voice networking in order to appreciate the benefits associated with technologies like VoIP. In this section, we’ll look at some of the core concepts that you’ll need to be familiar with from the world of traditional voice networks, otherwise known as telephony.

The telephone has become such a ubiquitous piece of equipment that we almost all take it for granted. Once a telephone line has been installed and configured, an end user simply plugs in a handset, picks up the receiver, and (hearing a dial tone) dials the number they wish to reach. Most people never give a second thought to what is happening behind the scenes, or to the technology involved. While the types of services associated with telephony (such as call waiting or caller identification) have matured in the last two decades, the basic operation of the telephone network hasn’t changed very much at all in the last 50 years.

In order to provide you with a better understanding of telephony concepts, the voice portion of this series will explore five major areas that impact not only how the public switched telephone network functions, but also the critical terms, concepts, and equipment involved in the process. The areas to be looked at in the following sections include:

  • Signaling basics
  • Switching equipment
  • Links and user equipment
  • Phone numbers
  • Network signaling
  • Value-added services

As you read through these articles, keep in mind not only the purpose of each individual element, but also how they interoperate.

Author: Dan DiNicolo

Dan DiNicolo is a freelance author, consultant, trainer, and the managing editor of He is the author of the CCNA Study Guide found on this site, as well as many books including the PC Magazine titles Windows XP Security Solutions and Windows Vista Security Solutions. Click here to contact Dan.