It is used by small businesses, large businesses, call centers, carriers and government agencies worldwide. Asterisk is used by almost the entire Fortune 1000 list of customers. Most often deployed by system integrators and developers, Asterisk can become the basis for a complete business phone system, or used to enhance or extend an existing system, or to bridge a gap between systems.

Asterisk-based telephony solutions offer a rich and flexible feature set. Asterisk offers classical PBX functionality and advanced features and interoperates with traditional standards-based telephony systems and Voice over IP systems. Asterisk offers the advanced features often associated with large, high-end (and high-cost) proprietary PBXs. The list below includes a sample of the features available in Asterisk.