OPBX is a free, open-source, multi-tenant business PBX built on Cloudonix CPaaS. It routes DID calls to extensions, ring groups, IVRs, business-hours rules, conference rooms, AI assistants, and AI load balancers. AI load balancers can distribute calls by round robin, priority, or percentage and fail over to another assistant. Inbound blacklists and outbound whitelists control unwanted calls and destinations. The outbound auto dialer supports scheduled campaigns, concurrent-call and call-speed limits, voicemail detection, retries, and real-time monitoring. Organizations are isolated for service-provider use, with Owner, PBX Admin, PBX User, and Reporter roles. Cloudonix handles VoIP and SIP services through a domain UUID, API key, and public webhook URL. The REST API has OpenAPI 3.1.0 documentation. Docker Compose is recommended, with minimum requirements of 4 GB RAM and 20 GB disk space.
Who it is for
It suits service providers and organizations needing multi-tenant PBX routing, campaigns, role controls, and AI call handling. Deployment requires Cloudonix CPaaS configuration and the documented system resources.
What is good
- Supports isolated multi-tenant organizations
- Includes AI call distribution and failover
- Auto dialer offers campaigns and monitoring
- Provides role-based access controls
- Free and open source
What to know first
- VoIP and SIP services depend on Cloudonix CPaaS
- Auto Dialer is limited to Owners and PBX Admins
- Minimum deployment requirements include 4 GB RAM
- Requires Docker Compose for recommended deployment
Verdict
OPBX combines PBX routing, outbound campaigns, tenant isolation, and AI call distribution in an open-source platform. Its Cloudonix dependency and deployment requirements should be considered during setup.
Compared on business phone systems
- Free plan
- Yes
- Call routing
- custom
