Core Concepts
This guide explains the fundamental concepts you need to understand before configuring your OPBX phone system.
Organizations
An organization represents a tenant in the multi-tenant OPBX system. All data belongs to exactly one organization, and users cannot access data from other organizations.
Key characteristics:
- Complete data isolation between organizations
- Each organization has its own extensions, DIDs, and configuration
- Users belong to exactly one organization
- Service providers can host multiple organizations on a single OPBX instance
If you are a service provider, you can create separate organizations for each of your customers. This keeps their data and configurations completely isolated.
Extensions
Extensions are numbered endpoints in your phone system. They are typically 3-5 digits long and serve as internal phone numbers.
Extension Types
| Type | Purpose | Example |
|---|---|---|
| User | SIP phone assigned to a person | Extension 100 for John Doe |
| Conference | Multi-party audio bridge | Extension 800 for team meetings |
| Ring Group | Group of extensions that ring together | Extension 600 for Sales team |
| IVR | Automated phone menu | Extension 700 for main menu |
| AI Assistant | Routes calls to AI providers | Extension 900 for AI receptionist |
| AI Load Balancer | Distributes calls across AI providers | Extension 901 for AI failover |
| Forward | Forwards calls to external numbers | Extension 101 forwarding to mobile |
| Custom Logic | Advanced routing via webhooks | Extension for custom integrations |
Extension numbers cannot be changed after creation. If you need a different number, delete the extension and create a new one.
DIDs (Phone Numbers)
DIDs (Direct Inward Dialing) are external phone numbers that callers dial to reach your organization. OPBX supports E.164 format (e.g., +1-555-123-4567).
Each DID has a destination that determines where incoming calls route:
- Extension
- Ring group
- IVR menu
- Business hours routing
- Conference room
- AI assistant
- AI load balancer
DIDs are configured in OPBX but must be purchased and assigned through your Cloudonix account or telecom provider.
Ring Groups
Ring groups distribute incoming calls among multiple extensions using different strategies.
Distribution Strategies
| Strategy | Behavior | Best For |
|---|---|---|
| Simultaneous | All extensions ring at once | Small teams where anyone can answer |
| Round Robin | Rotates through extensions evenly | Balancing workload across agents |
| Sequential | Rings extensions in order | Escalation chains or priority routing |
Each ring group has:
- Member extensions
- Ring timeout (how long to wait before giving up)
- Fallback action (voicemail, another destination, or hang up)
IVR Menus
IVR (Interactive Voice Response) menus provide automated phone navigation. Callers press digits on their keypad to route their call.
IVR Components
- Greeting: Audio played when the menu starts (audio file, URL, or text-to-speech)
- Options: Digit presses (0-9, *, #) mapped to destinations
- Timeout: Action taken if no input received
- Invalid: Action taken if invalid digit pressed
IVR menus support text-to-speech for dynamic content. Enter plain text and OPBX converts it to spoken audio using Cloudonix TTS services.
Business Hours
Business hours enable time-based call routing. Calls route to different destinations depending on whether your business is open or closed.
Configuration Elements
- Weekly Schedule: Define open hours for each day of the week
- Time Zones: Set your local time zone for accurate routing
- Exception Dates: Specify holidays or special closures
- Open Destination: Where calls go during business hours
- Closed Destination: Where calls go after hours (voicemail, emergency line, etc.)
Business hours use the organization's configured time zone. Ensure this is set correctly in Settings before configuring business hours.
Conference Rooms
Conference rooms provide multi-party audio bridges for meetings.
Features
- PIN Protection: Optional numeric PIN to join
- Host PIN: Special PIN for host controls
- Recording: Option to record conference sessions
- Host Waiting: Wait for host to join before starting
Conference rooms have their own extension numbers and can be destinations for DIDs or IVR options.
AI Assistants
AI assistants connect calls to AI providers via SIP or WebSocket protocols.
Supported Providers
OPBX supports 17 AI providers including:
- Bland AI
- Retell AI
- Vapi
- Ultravox
- And others
Each AI assistant configuration includes:
- Provider selection
- SIP or WebSocket connection details
- API credentials
- Custom parameters for the AI service
AI Load Balancers
AI load balancers distribute calls across multiple AI providers for redundancy and capacity management.
Distribution Methods
| Method | Description |
|---|---|
| Round Robin | Cycles through providers in order |
| Random | Selects a random provider for each call |
| Priority | Uses primary provider, falls back on failure |
Load balancers help ensure high availability for AI-powered call handling.
Auto Dialer
The Auto Dialer manages outbound campaigns for sales, surveys, or notifications.
Key Concepts
- Campaigns: Define call lists, schedules, and retry logic
- Distribution Lists: Phone numbers to call
- Rate Limiting: Control calls per minute to manage capacity
- Scheduling: Set active calling hours
- Retry Logic: Automatic redial on busy or no-answer
The Go-based dialer worker processes campaigns and initiates calls through Cloudonix.
Call Routing Flow
This diagram shows how an inbound call flows through the OPBX system:
The call enters through a DID, which determines the initial destination. From there, the call may traverse multiple routing rules before reaching its final destination.
Next Steps
Now that you understand these core concepts, you are ready to:
- Create extensions for your users
- Configure Phone Numbers for inbound calls
- Set up ring groups for departments
- Build IVR menus for self-service
- Define business hours for time-based routing