Overview: Telephony
Connect Ultravox to traditional phone networks for AI-powered voice calls.
Ultravox Realtime is a “BYOT” (bring your own telephony) platform and integrates with major telephony providers to enable AI-powered voice applications that work with regular phone numbers. Your AI agents can make outbound calls and answer inbound calls through traditional phone networks.
Connection Methods
Ultravox supports multiple ways to connect to phone networks:
Telephony Providers
Native support for Twilio, Telnyx, Plivo, and Exotel.
Voice Platforms
Integrations with Voximplant and jambonz.
SIP
Connect your existing phone system through our SIP integration.
Learn more: Supported Providers →
Learn more: SIP Guide →
Key Capabilities
Create AI agents that can handle both directions of phone communication:
- Outbound Calls - AI agents initiate calls to users.
- Incoming Calls - AI agents answer calls from users.
You can also enable your agents to handle more advanced tasks:
- Call Transfers - Route calls between agents and humans.
- IVR Flows - Interactive voice response with keypad input using Ultravox’s native support for DTMF.
Connecting Ultravox to a Phone Call
It can be a bit confusing because Ultravox Realtime uses the concept of a “call” to mean a voice session between an AI agent and another party. For phone calls, you will accept inbound or make outbound calls via your chosen telephony provider and then connect those calls to an Ultravox call.
Creating an Ultravox call that you can connect with a phone call requires specific parameters in the Create Call command:
Tells Ultravox which protocol to use. For phone calls, must be set to one of:
{"telnyx": {}}
, {"twilio": {}}
, or {"plivo": {}}
.
Defaults to {"webRtc": {}}
.
Tells Ultravox who should speak first.
For outbound calls, typically set to user: {}
.
The default is agent: {}
.
Learn More
- Discover how to get started with Supported Providers.
- Learn how to integrate with your existing phone system in the SIP Guide.
- Set your agent up to receive Inbound Calls or make Outbound Calls.