asteriskThe official Asterisk Project repository.

Asterisk

Asterisk is an open-source PBX (Private Branch Exchange) and telephony toolkit that serves as middleware between internet and telephony channels. It enables organizations to build custom voice, video, and messaging applications while supporting both modern VoIP/SIP and traditional PSTN telephony interfaces.

Key Features

• Unified Communications Platform: Handles Internet telephony, PSTN integration, TDM/analog services, and traditional PBX functionality in a single system
• Modular Architecture: Extensive module system allowing selective compilation and customization of features based on specific deployment needs
• Multi-Protocol Support: Full support for SIP, VoIP, analog interfaces, and digital telephony hardware from various manufacturers
• Hardware Compatibility: Works with Sangoma interface cards, PortAudio sound cards, and Xorcom Astribank channel banks

Use Cases

• Business PBX Systems: Replace or supplement traditional PBX systems with open-source infrastructure for call routing, IVR, and voicemail
• VoIP Service Providers: Build carrier-grade telephony services and hosted PBX solutions
• Telecommunications Integration: Connect legacy PSTN systems with modern SIP-based communications and internet telephony
• Custom Call Centers: Develop specialized call handling applications with dialplans, call transfers, and advanced routing logic

Who Is It For

Asterisk is designed for telecommunications professionals, system administrators, and developers who need a flexible, self-hosted PBX solution. It's ideal for organizations requiring tight control over their telephony infrastructure, custom feature development, or cost-effective alternatives to proprietary PBX systems.