Table of Contents:

Definition and Overview

1. Introduction

2. Intranet Telephony Paves the Way for Internet Telephony

3. Technical Barriers

4. Standards

5. Future of Voice-over-Internet Protocol (VoIP) Telephony

Self-Test

Glossary

PDF of this tutorial

Definition
Internet telephony refers to communications services—voice, facsimile, and/or voice-messaging applications—that are transported via the Internet, rather than the public switched telephone network (PSTN). The basic steps involved in originating an Internet telephone call are conversion of the analog voice signal to digital format and compression/translation of the signal into Internet protocol (IP) packets for transmission over the Internet; the process is reversed at the receiving end.

Overview
This tutorial discusses the ongoing but rapid evolution of Internet telephony, the market forces fueling that evolution and the benefits that users can realize, as well as the underlying technologies. It also examines the hurdles that must be overcome before Internet telephony can be adopted on a widespread basis.