PBXen

PBXen is an open-source software platform designed to implement software-based private branch exchanges (PBXs). It provides telephony functionality for organizations seeking to replace hardware PBX systems with a centralized, scalable, software-driven solution. PBXen emphasizes SIP-based VoIP, Web Real-Time Communication (WebRTC) support, and integration with cloud services.

Key features include call control and routing, voicemail and voicemail-to-email, IVR menus, auto-attendant, conferencing, call recording, and presence information. The platform supports trunking via SIP trunks, extensible dial plans, and integration with CRM or helpdesk systems through exposed APIs.

Architecture commonly comprises a core engine, a signaling layer handling SIP and WebRTC, a media interface, a data store for configuration and logs, and a plugin or module framework for extensibility. It supports containerized deployment (Docker or Kubernetes), high-availability clustering, and multi-tenant configurations for service providers or large deployments. Security features include TLS for signaling and SRTP for media, plus authentication and access control.

PBXen is developed in an open-source model with community contributions and documentation. It is designed to interoperate with existing telephony infrastructure, including gateway devices, SIP trunks, and third-party applications, while offering an API-driven approach to automation and integration.

In practice, PBXen has been adopted by small to mid-sized organizations seeking cost-effective, flexible telephony solutions and by service providers testing cloud-based PBX services. Critics note that successful deployment requires familiarity with telephony concepts, network security, and system administration.

Related projects include Asterisk, FreeSWITCH, and Kamailio, which explore complementary or overlapping aspects of open-source telephony platforms.