Chapter 1: Overview
What is Asterisk®?
Asterisk is the world’s leading open source telephony engine and tool kit.
Offering flexibility unheard of in the world of proprietary
communications, Asterisk empowers developers and integrators to create
advanced communication solutions...for free. Asterisk is released as open
source under the GNU General Public License (GPL), and it is available
for download free of charge. Asterisk is the most popular open source
telephony software available, with the Asterisk Community being the top
influencer in VoIP.
Asterisk as a Phone Switch (PBX)
Asterisk can be configured as the core of an IP or hybrid PBX, switching
calls, managing routes, enabling features, and connecting callers with the
outside world over IP, analog (POTS), and digital (T1/E1/J1/BRI)
connections.
Asterisk runs on a wide variety of Linux distributions. It provides all of
the features you would expect from a PBX including many advanced
features that are often associated with high end (and high cost) proprietary
PBXs. Asterisk's architecture is designed for maximum flexibility and
supports Voice over IP in many protocols, and can interoperate with
almost all standardsbased telephony equipment using relatively
inexpensive hardware.
Asterisk as a Gateway
It can also be built out as the heart of a media gateway, bridging the
legacy PSTN to the expanding world of IP telephony. Asterisk’s modular
architecture allows it to convert between a wide range of communications
protocols and media codecs.
Digium, Inc.
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