PBX Extension Registration | Deploy AI Agents as SIP Extensions
Register AI agents directly to your PBX as standard extensions. No new phone numbers, no SIP trunks, just instant AI integration with existing phone systems.
Revolutionary approach to AI voice integration. Instead of requiring new phone numbers or complex SIP trunk configurations, your AI agent registers directly to your PBX as extension 101, 200, or any available extension. Works with Cisco, Avaya, 3CX, FreePBX, and any SIP-compatible system. 5-minute setup, zero infrastructure changes.
Key Highlights
Discover what makes this feature stand out
Register as Standard Extension
AI agent becomes extension 101, 200, or any number on your PBX. Just like a desk phone or softphone, but powered by AI. No new phone numbers needed.
5-Minute Setup
Create SIP credentials in your PBX, register the extension in VoiceInfra, and you're live. Auto-fill logic and smart defaults eliminate configuration errors.
Works with Any PBX
Cisco, Avaya, 3CX, Mitel, FreePBX, Asterisk, Yeastar, RingCentral, Nextiva, 8x8. If it supports standard SIP extensions, it works with VoiceInfra.
Native PBX Features
AI extension works with ring groups, IVR menus, call transfer, hold, conferencing, and recording. Integrates seamlessly into existing call flows.
Benefits
See how this feature can transform your business
No new phone numbers needed - use existing business infrastructure
Zero PBX reconfiguration - minimal changes to current setup
5-minute deployment from registration to live AI agent
Works with all PBX features: transfer, hold, conferencing, recording
Outbound registration requires no firewall changes
Real-time status monitoring (REGED, NOREG, RUNNING, ALIASED)
Encrypted credentials with SIP/TLS support when available
Why Choose VoiceInfra for PBX Extension Registration | Deploy AI Agents as SIP Extensions
Built by engineers who understand enterprise telephony complexity
Instant Deployment
Deploy in minutes, not months. No complex integrations or lengthy setup processes required.
Enterprise Security
Enterprise-grade infrastructure with end-to-end encryption and advanced security features.
Proven Scalability
Handle thousands of concurrent calls with fast response times and high availability.
Expert Support
Direct access to our engineering team during setup and beyond. White-glove onboarding included.
Use Cases
Explore how this feature can be applied in different scenarios
After-Hours Support
Extension 100 handles calls when office is closed, qualifying leads and booking appointments while you sleep
Department Routing
IVR menu 'Press 1 for Sales' routes to AI extension 201 for instant lead qualification and appointment booking
Overflow Handling
Ring group includes AI extension to handle call spikes during peak hours without busy signals
Multilingual Support
Different AI extensions for different languages - ext 301 for Spanish, 302 for French, 303 for Mandarin
Specialized Functions
Appointment booking on ext 301, order status on ext 302, payment processing on ext 303
Call Screening
AI extension qualifies leads and gathers information before transferring to sales team with full context
How It Works
Get started with this feature in a few simple steps
Identify Available Extension
Choose unused extension number on your PBX (e.g., 101, 200, 999). Create SIP credentials in PBX admin panel and note the domain/IP address.
Register Extension in Platform
Navigate to Phone Numbers → Add Extension. Fill in extension number, friendly name, SIP domain, username, password, and transport protocol (TCP/UDP).
Smart Defaults & Validation
Auto-fill logic sets proxy to domain and reg_proxy to proxy. Real-time validation ensures proper format and required fields before submission.
Automatic SIP Registration
Platform initiates SIP REGISTER request to PBX, authenticates with credentials, and maintains persistent registration with periodic refreshes.
Status Monitoring & Integration
Monitor real-time status (REGED/NOREG/RUNNING). AI extension now works in ring groups, IVR menus, direct dial, and call transfers.
Implementation Timeline
Get up and running quickly with our streamlined deployment process
Day 1
Initial setup and configuration
Day 2-3
Integration and testing phase
Day 4-5
Training and optimization
Day 6+
Full production deployment
Technical Specifications
Enterprise-grade infrastructure built for reliability and scale
99.9% Uptime SLA
Enterprise-grade reliability with redundant infrastructure
Sub-second Response
Ultra-low latency for natural conversation flow
Global Infrastructure
Worldwide coverage with regional data centers
Multi-LLM Support
OpenAI, Anthropic, Google - choose the best model for your needs
Frequently Asked Questions
Find answers to common questions about this feature
Any PBX system that supports standard SIP extensions works with VoiceInfra. This includes open source systems (FreePBX, FusionPBX, Asterisk), commercial systems (3CX, Yeastar, Avaya, Cisco, Mitel), cloud PBX (RingCentral, Nextiva, 8x8, Vonage), and enterprise systems (Vicidial, Genesys, Five9). If your PBX can register a SIP extension, it can register an AI agent.
Traditional SIP trunk integration requires you to configure your PBX to send calls TO an external platform. Extension registration reverses this - the AI platform registers TO your PBX as a standard extension. This eliminates complex trunk configuration, firewall changes, and carrier coordination. It's the same process as adding a desk phone or softphone.
No. Because VoiceInfra registers TO your PBX (outbound registration), no inbound firewall rules or port forwarding are required. The AI extension initiates the connection to your PBX, just like a remote softphone would.
Yes. The AI extension has full access to PBX features including call transfer, hold, and conferencing. When transferring, the AI provides complete conversation context to the human agent, ensuring seamless handoffs.
5 minutes from start to finish. Create SIP credentials in your PBX (2 minutes), register the extension in VoiceInfra (2 minutes), and test (1 minute). The AI agent is immediately available for calls through your existing PBX routing rules.
Real-time status monitoring alerts you if registration fails. You can configure fallback routing in your PBX to send calls to human agents if the AI extension shows NOREG status. Most deployments include ring groups with both AI and human extensions for automatic failover.
Absolutely. Register different AI agents for different departments, languages, or functions. Extension 201 for sales, 301 for support, 401 for Spanish-language calls, etc. Each extension can have unique AI agent configurations and routing rules.
Yes. Because the AI extension is a standard PBX endpoint, all existing call recording, compliance policies, and reporting systems treat it like any other extension. Calls appear in standard PBX call logs and are subject to the same recording and retention policies.
Ready to transform your operations?
Schedule a demo to see how our solutions work for your industry.