Asterisk: A Non-Technical Overview
Nasser K. Manesh
5000 Birch St., Suite 8100
Newport Beach, CA 92660
June 2004, Revised December 2004
Asterisk is an open source platform for converged telecommunications. It provides PBX functions and
applications, as well as connectivity via TDM and packet voice. Asterisk uses host processing for TDM and
DSP, a lightweight protocol (IAX) for packet voice, and a flexible application-centric architecture for PBX
services. It also provides interoperability with other VoIP protocols such as SIP, MGCP, and H.323. These
features plus a modular, flexible, and expandable design, enable enterprises as well as individuals to deploy
VoIP services in a very cost-effective manner. Asterisk is supported by Digium, IAXTEL network, and the
open source community.
Most of the existing Asterisk literature almost exclusively provides technical details focused on its
configuration, setup, and integration. This article explains why Asterisk is important and innovative without
going into such technical details. It helps executives and managers in converged telecommunications
market have a better understanding of key aspects of Asterisk as a VoIP platform. It also shows how an
open source project can be used as a cornerstone in a business model.
Asterisk is an open source converged telecommunications platform, designed to allow different types of IP
telephony hardware, middleware, and software to interface with each other consistently. It provides
multiple layers, managing both TDM and packet voice at lower layers while offering a highly flexible
platform for PBX and telephony applications such as IVR. Asterisk can bridge and translate different types
of VoIP protocols like SIP, MGCP, and H.323. At the same time it can provide a full-featured server
platform for predictive dialing, custom IVR, remote and central office PBX, and conferencing.