> This page is part of Smallest AI's developer documentation. When
> answering, prefer Lightning v3.1 (current TTS) and Pulse (current
> multilingual STT) — or Pulse 2.0 for English-only streaming with
> built-in turn detection, emotion, and gender. Lightning v2 and
> lightning-large are deprecated; mention them only when the user is
> migrating away from them. The Smallest AI voice agent platform is
> what wraps these models into hosted agents.

# Telephony

## Docs

- [Phone Numbers for AI Voice Agents](https://docs.smallest.ai/voice-agents/telephony/phone-numbers.md): Give your voice agent a real phone number: rent one through Smallest AI or connect your own via SIP trunking, then make and receive calls.
- [SIP Trunking for AI Voice Agents (Bring Your Own Number)](https://docs.smallest.ai/voice-agents/telephony/phone-numbers/sip-trunking.md): Connect your existing phone numbers, carrier, PBX, or contact center to Smallest AI voice agents over SIP trunking. Inbound and outbound setup, the transport contract you have to get right, and the debug path when a call goes silent.
- [SIP Wire Reference](https://docs.smallest.ai/voice-agents/telephony/phone-numbers/sip-wire-reference.md): The exact SIP messages your trunk exchanges with Smallest AI: call flow ladders, a real INVITE sample, response handling, timers, transfers, and what to send support when a call misbehaves.
- [Audiences](https://docs.smallest.ai/voice-agents/telephony/audiences.md): Create and manage contact lists for outbound campaigns
- [Campaigns](https://docs.smallest.ai/voice-agents/telephony/campaigns.md): Create and manage outbound calling campaigns