Customer Supports & Sells
Asterisk is an open source PBX that runs on Linux and many other operating systems. It was created in 1999 byMark Spencer, the founder of Digium, which is a privately-held company based in Huntsville, Alabama. Among other things, Digium is specialized in developing hardware for use with Asterisk. As a result, Asterisk may not be vendor-independent, but it is still the most popular open source PBX.
The development of Asterisk was significant, because it marked the first time that organizations and individuals could set up their own PBX without losing an arm and a leg. Instead, the cost of an Asterisk PBX need only consist of the hardware that it runs on and the phones that connect to it; all of which are standardized, readily available and thus affordable.
Like any PBX, Asterisk is basically a router for incoming and outgoing telephone calls. It can be configured to support a range of external connections using various media and protocols, as well as a large number of endpoints: usually telephones that connect to Asterisk via the network (or the Internet) using one protocol or another.
This page describes how to install a minimal, SIP-only Asterisk system on Debian 5.0 (lenny). The operating system comes with Asterisk 1.4.21 and Zaptel 1.4.11. Actually, Debian supplies two Zaptel packages: zaptel and zaptel-source, with a zaptel-modules package that must be compiled from the latter. The installation and configuration procedures below assume that a minimal Debian lenny system is already up and running, that a SIP-capable phone is available, possibly through the use of a SIP adapter, and that an external SIP account is available through a commercial VoIPprovider.
Asterisk is a framework for multi-protocol building, communications with real-time applications and solutions. Asterisk is to realtime voice and video applications as what Apache is to web applications: the underlying platform. Asterisk abstracts the complexities of communications protocols and technologies, allowing you to concentrate on creating innovative products and solutions.
You can use Asterisk to build communications applications, things like business phone systems (also known as PBXs), call distributors, VoIP gateways and conference bridges. Asterisk includes both low and high-level components that significantly simplify the process of building these complex applications. See the Asterisk Applications section for more examples.