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Extension Types

OPBX supports multiple extension types, each designed for specific use cases. This document provides detailed information about each type.

Extension Type Comparison​

FeatureUserConferenceRing GroupIVRAI AssistantForward
Requires User✅❌❌❌❌❌
SIP Credentials✅❌❌❌❌❌
Voicemail✅❌❌❌❌❌
Outbound Calls✅❌❌❌❌❌
Multi-party❌✅✅❌❌❌

User Extension​

Purpose: Direct extension for individual users to make and receive calls.

When to Use​

  • Employee desk phones
  • Softphone users
  • Anyone who needs to make and receive calls

Key Features​

  • SIP Credentials: Each user extension gets unique SIP credentials for phone registration
  • Voicemail: Built-in voicemail box for missed calls
  • Outbound Calling: Can place calls to external numbers
  • User Assignment: Must be assigned to a user account
  • Call Features: Supports call forwarding, call waiting, caller ID

Configuration​

Required Fields:

  • Extension number
  • User assignment (can be done later)

Automatically Generated:

  • SIP password (32-character secure password)

Optional Settings:

  • Voicemail enabled/disabled
  • Call forwarding rules
  • Status (active/inactive)

SIP Credentials​

User extensions are the only type with SIP credentials, enabling phones to register:

  • Username: Extension number
  • Password: Auto-generated 32-character hex string
  • Server: Provided by Cloudonix integration

SIP passwords are sensitive. They are hidden from API responses and access is logged for audit purposes.

Conference Room​

Purpose: Multi-party conference bridge for group meetings.

When to Use​

  • Team meetings
  • Client conferences
  • Training sessions
  • Any scenario requiring 3+ participants

Key Features​

  • Multiple Participants: Supports many simultaneous callers
  • PIN Protection: Optional PIN for secure conferences
  • No User Required: Anyone with the extension number can join
  • Moderator Controls: Advanced features for managing participants

Configuration​

Required Fields:

  • Extension number
  • Associated conference room configuration

Optional Settings:

  • PIN protection
  • Maximum participants (plan-dependent)
  • Entry/exit announcements
  • Moderator PIN

Usage Example​

1. Caller dials 400 (conference extension)
2. If PIN enabled, enter PIN
3. Joined to conference
4. Multiple participants can join simultaneously

Ring Group​

Purpose: Route incoming calls to multiple extensions simultaneously or sequentially.

When to Use​

  • Department coverage (Sales, Support)
  • Hunt groups
  • Overflow handling
  • Shared responsibility scenarios

Key Features​

  • Multiple Members: Add multiple user extensions to the group
  • Ring Strategies: Different ways to distribute calls
  • Fallback: Destination if no one answers
  • No User Required: Routes to other extensions

Ring Strategies​

StrategyDescriptionBest For
SimultaneousAll members ring at onceSpeed of answer is priority
Round RobinRotate through members evenlyDistribute workload
SequentialRing in fixed orderPriority-based routing
Least RecentRing member who answered longest agoFair distribution

Configuration​

Required Fields:

  • Extension number
  • Associated ring group configuration

Ring Group Settings:

  • Members (user extensions)
  • Ring strategy
  • Ring timeout
  • Fallback destination

Usage Example​

1. Caller dials 500 (Sales ring group)
2. System rings all 3 sales team members (simultaneous)
3. First person to answer gets the call
4. If no answer after 20 seconds, goes to voicemail

IVR Menu​

Purpose: Interactive Voice Response system for automated call routing.

When to Use​

  • Main company number routing
  • After-hours handling
  • Self-service options
  • Department selection

Key Features​

  • Key Press Routing: "Press 1 for Sales, 2 for Support"
  • Multi-level Menus: Sub-menus for complex routing
  • Custom Greetings: Recorded or uploaded audio
  • No User Required: Automated system

Configuration​

Required Fields:

  • Extension number
  • Associated IVR menu configuration

IVR Settings:

  • Welcome greeting
  • Menu options (key press → destination)
  • Timeout handling
  • Invalid input handling
  • Business hours vs. after-hours menus
"Thank you for calling ACME Corporation.
Press 1 for Sales
Press 2 for Technical Support
Press 3 for Billing
Press 0 to speak with an operator
Or stay on the line to leave a message"

Key Mappings:

  • 1 → Sales Ring Group (500)
  • 2 → Support Ring Group (501)
  • 3 → Billing Extension (350)
  • 0 → Operator Extension (100)
  • Timeout → Voicemail

AI Assistant​

Purpose: AI-powered virtual assistant to handle calls automatically.

When to Use​

  • After-hours support
  • High-volume call handling
  • FAQ automation
  • Call screening

Key Features​

  • Natural Language: Understands caller intent
  • 24/7 Availability: No human required
  • Call Handling: Can answer questions, take messages, route calls
  • Integration: Works with AI service providers

Configuration​

Required Fields:

  • Extension number
  • AI provider selection
  • Phone number (for AI service)

AI Settings:

  • Provider credentials
  • Conversation script/training
  • Escalation rules (when to transfer to human)
  • Language settings

Usage Example​

1. Caller dials 600 (AI Assistant)
2. AI answers: "Hello, I'm ACME's virtual assistant. How can I help?"
3. Caller asks about store hours
4. AI provides information
5. Caller asks about order status
6. AI collects order number and looks up status
7. Call completes without human intervention

Call Forwarding​

Purpose: Forward incoming calls to an external phone number.

When to Use​

  • Forwarding to mobile phones
  • Temporary relocation
  • After-hours forwarding
  • Backup coverage

Key Features​

  • External Numbers: Forward to any phone number
  • Simple Setup: Just enter the destination number
  • No User Required: Direct forwarding
  • Transparent: Callers don't know they're being forwarded

Configuration​

Required Fields:

  • Extension number
  • Forward-to number (external)

Number Format:

  • E.164 format recommended: +1234567890
  • Local format as configured in your system

Usage Example​

1. Caller dials 700 (Forward extension)
2. System forwards to +1-555-123-4567
3. External phone rings
4. Call connects caller to external number

Important Notes​

  • Call forwarding may incur charges based on your plan
  • Forwarded calls use outbound calling minutes
  • Consider using time-based routing for business hours vs. after-hours

AI Load Balancer​

Purpose: Distribute incoming calls across multiple AI assistants using load balancing algorithms.

When to Use​

  • High-volume AI call handling
  • Redundancy for AI services
  • Distributing load across regions
  • Advanced AI routing scenarios

Key Features​

  • Distribution Algorithms: Round-robin, least connections, etc.
  • Multiple AI Assistants: Pool of AI services
  • Health Monitoring: Automatic failover
  • Load Management: Prevents overloading single AI instance

Configuration​

Required Fields:

  • Extension number
  • Associated AI load balancer

Load Balancer Settings:

  • Pool of AI assistants
  • Distribution algorithm
  • Health check configuration
  • Failover settings

Extension Type Selection Guide​

Use this guide to choose the right extension type:

For Individual Users​

→ User Extension

For Group Meetings​

→ Conference Room

For Department Coverage​

→ Ring Group

For Automated Call Routing​

→ IVR Menu

For AI-Powered Handling​

→ AI Assistant or AI Load Balancer

For External Forwarding​

→ Call Forwarding

For Complex Scenarios​

Combine multiple types:

  • IVR → Ring Group → User Extension
  • IVR → AI Assistant → User Extension (escalation)
  • Ring Group → Conference Room (overflow)

Next Steps​

Related Documentation: