Asterisk is a communications server software and an open source framework for building communications applications.
Asterisk is a communications server software and an open source framework for building communications applications. Asterisk powers IP PBX systems, VoIP gateways, conference servers and other custom solutions. It is used by small businesses, large businesses, call centers, carriers and government agencies, worldwide. Asterisk is free and open source. Asterisk is sponsored by Digium.
Asterisk supports different Voice over IP (VoIP) protocols (eg. IAX2 and SIP). Asterisk also supports integration into the legacy analog network or isdn over telephony interface cards with dahhdi.