Design and Implementation of a VoIP Gateway

19.10.2001

Abstract

Voice over IP, also known as IP Telephony, has until now been considered a substandard technology. However, being today’s fastest growing segment in the telecommunications industry, Voice over IP is emerging as a powerful competitor to the services provided by the traditional Public Switched Telephone Network. To successfully develop Voice over IP solutions, mechanisms are needed to integrate this new and evolving technology with the traditional circuit switched telephone networks.

We describe the design and implementation of a Voice over IP gateway permitting the routing of voice traffic and control information between circuit switched telephone networks and packet based computer networks. The use of inexpensive hardware, a high-level programming language, and a flexible and modular design are key elements of the implementation. We identify the requirements for such an infrastructure, analyze the protocols, discuss the design choices and describe its implementation.