PBX-NATIVE VOICE AI

AI Voice Agents That Work On Your Existing PBX

Register AI agents as extensions on your phone system in 5 minutes. Zero hardware changes. Zero carrier swaps. Works with Asterisk, FreeSWITCH, Cisco, Avaya, 3CX, and any SIP-compatible PBX.

No hardware needed
Works with any SIP PBX
5-minute deployment
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Your PBXAsterisk / Cisco / Avaya
SIPPRIPSTN
5 min
AI Voice AgentsPBX Extensions
24/7 Calls
50+ Languages
Real-time Analytics
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How It Works: AI Extensions on Your PBX

Four steps from your current setup to AI-powered calls. No disruption to your existing infrastructure.

01

Connect Your PBX

Point your PBX at VoiceInfra's SIP endpoint. We provide the trunk configuration details you copy and paste into your PBX admin panel. Works with any SIP-compatible system.

02

Create Your AI Agent

Use our no-code builder to define your agent's personality, knowledge base, and actions. Choose from 5+ LLM providers and premium voices in 50+ languages.

03

Assign an Extension

Give your AI agent an extension number on your PBX. Route calls via IVR, hunt group, direct extension, or any existing call flow.

04

Go Live

Calls to that extension are now handled by AI. Monitor performance, review transcripts, and optimize from the VoiceInfra dashboard in real time.

WHY VOICEINFRA

Why Businesses Choose VoiceInfra for Their PBX

Unlike cloud-only voice AI platforms, VoiceInfra is built to work inside your existing phone infrastructure.

Zero Hardware Changes

Your PBX stays exactly as it is. VoiceInfra registers AI agents as software-based SIP extensions. No new boxes, no rewiring, no downtime.

Deploy in 5 Minutes

Create an AI voice agent, assign it an extension number, and it's live. Most customers go from signup to first call in under 5 minutes.

Works With Existing Call Flows

AI agents integrate with your current IVR menus, hunt groups, ring groups, and call queues. Route calls to AI just like you route to human agents.

Keep Your Current Carrier

No need to change telecom providers. VoiceInfra works with your existing SIP trunks, PRI lines, and PSTN connections.

Unlimited Concurrent Calls

Scale from 10 to 10,000 simultaneous calls without adding hardware. Your PBX capacity is the only limit.

Full Context on Transfer

When an AI agent hands off to a human, the full conversation history, caller intent, and collected data are passed along. No repeating yourself.

Works With Your Phone System

If your PBX speaks SIP, VoiceInfra works with it. Here are the systems our customers use:

Asterisk / FreePBX

Open-source PBX used by millions of businesses. VoiceInfra registers as a standard SIP extension.

FreeSWITCH

High-performance softswitch powering many commercial PBX platforms. Full SIP compatibility.

Cisco UCM

Enterprise-grade PBX. VoiceInfra connects via SIP trunk or direct extension registration.

Avaya Aura / IP Office

Legacy and modern Avaya systems supported. Deploy AI agents alongside existing call flows.

3CX

Popular software-based PBX. Register VoiceInfra as an extension in under 5 minutes.

Mitel MiVoice

Enterprise telephony. Connect via SIP for seamless AI agent integration.

Yeastar / Grandstream

SMB and mid-market PBX appliances. Standard SIP extension registration works immediately.

Any SIP-Compatible System

If your phone system speaks SIP, VoiceInfra works with it. No exceptions.

REAL-WORLD APPLICATIONS

How Businesses Use AI Extensions on Their PBX

24/7 Auto-Attendant

Replace your traditional IVR with an AI receptionist that understands natural language. Callers say what they need in their own words. The AI routes them, answers questions, or takes a message. Works after hours, weekends, and holidays without hiring staff.

IT Helpdesk Triage

Add an AI agent as an internal extension for IT support. It resets passwords, answers common questions, and creates tickets. Only escalates to human IT staff when necessary. Reduce Level 1 ticket volume by 60%+.

HR & Employee Services

Deploy an AI agent as an internal HR extension. Employees call to check PTO balances, understand benefits, or ask policy questions. The AI handles routine queries and escalates sensitive matters to the right HR team member.

Overflow Call Handling

When your human agents are at capacity, route overflow calls to AI. The AI handles the call or collects information for a callback. No more busy signals or endless hold times during peak hours.

PBX-Native vs. Cloud-Only Voice AI

Most voice AI platforms are cloud-only. They work as standalone services. VoiceInfra works inside your PBX. Here's why that matters:

Feature VoiceInfraCloud-Only Voice AI
PBX extension registration
Extension-based call routing
IVR / hunt group integration
Keeps your current carrierMay require carrier change
On-net calling (no PSTN hop)
Call transfer with full contextLimited or external
Zero hardware changes
Multi-LLM support5+ providersVaries by vendor
On-premise deployment optionRare
SIP extension registration

Comparison based on publicly available documentation and pricing pages as of July 2026. Check each platform directly for current information.

Frequently Asked Questions

Everything you need to know about adding AI voice agents to your PBX.

VoiceInfra uses standard SIP protocol to connect to your PBX. We provide a SIP trunk configuration that you add to your PBX admin panel - the same way you'd add any SIP trunk. For systems that support extension registration (Asterisk, FreeSWITCH, 3CX), VoiceInfra can register directly as an extension. No additional hardware, no carrier changes.

If your PBX supports SIP - and virtually all PBX systems from the past 20 years do - VoiceInfra will work with it. We have customers running on Asterisk, FreePBX, FreeSWITCH, Cisco UCM, Avaya Aura, Avaya IP Office, 3CX, Mitel, Yeastar, Grandstream, and many others. If you're unsure, our engineering team will verify compatibility during your trial.

No. VoiceInfra works alongside your existing carrier setup. Your PSTN lines, SIP trunks, and PRI connections stay exactly as they are. VoiceInfra sits inside your PBX as an extension - calls route to AI through your PBX using your existing infrastructure.

Most customers complete the technical setup in under 30 minutes, and many are live within 5 minutes. The process is: (1) create a VoiceInfra account, (2) build your first AI agent using our no-code builder, (3) add our SIP trunk details to your PBX, (4) route calls to your new AI extension. Our support team can guide you through it on a live call if needed.

Yes. VoiceInfra AI agents can transfer calls to any extension, ring group, or queue on your PBX with full conversation context. The human agent sees a summary of what was discussed, what the caller needs, and any data the AI collected - so the caller never has to repeat themselves.

Subscription plans start at $49/mo with full platform access, AI providers, support, and infrastructure included. No setup fees, no hardware costs. Each plan includes a monthly minute allocation with tiered overage rates for additional usage. Visit our pricing page for current plans and rates.

VoiceInfra uses end-to-end encryption for all calls. Audio is processed in real-time and not stored unless you enable call recording. We can deploy in your AWS VPC for HIPAA, SOC 2, or GDPR compliance requirements. Contact our sales team to discuss your specific compliance needs.

You define fallback behavior. Common configurations include: transfer to a human agent with full context, redirect to voicemail, offer a callback, or route to a different department. You can also set up escalation rules - for example, if the caller says "speak to a manager" or shows frustration, they are immediately transferred.

See AI Agents Working on Your PBX

We'll show you exactly how VoiceInfra integrates with your specific phone system - live, in under 30 minutes.

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