AI Voice Infrastructure Overview

Built for AI Voice

CloudVNO AI Voice Infrastructure is designed specifically for AI voice agents — Vapi, Retell, Bland.ai, OpenAI Realtime API, and custom LLM-powered agents. Standard telephony wasn't built for real-time AI inference. We were.

Key Specifications

Metric	Value
Media latency (SIP)	< 50ms (p99)
Media latency (WebSocket)	< 30ms (p99)
Concurrent calls	1,000+ per account
Number provisioning	< 2 seconds
STIR/SHAKEN	Full attestation (A)
Codecs	G.711 (PCMU/PCMA), G.722, Opus

Integration Patterns

Pattern 1: SIP Trunk (Recommended)

Connect your AI agent platform to CloudVNO via SIP trunk. Best for platforms that support SIP (Vapi, Retell, Bland).

User calls CloudVNO DID
  → CloudVNO routes to your SIP trunk
    → Your AI agent platform (Vapi/Retell)
      → LLM inference (OpenAI/Anthropic)
        → Audio back to CloudVNO
          → Delivered to caller

Pattern 2: WebSocket Audio Bridge

For custom AI agents, use CloudVNO's WebSocket bridge to stream raw audio to/from your LLM:

# When a call comes in, CloudVNO sends to your webhook
@app.route("/ai-voice-webhook", methods=["POST"])
def ai_voice():
    call_sid = request.form["CallSid"]

    return Response(f"""
    <?xml version="1.0" encoding="UTF-8"?>
    <Response>
        <Connect>
            <Stream url="wss://yourapp.com/audio-stream/{call_sid}"/>
        </Connect>
    </Response>
    """, mimetype="text/xml")

Getting Started with Vapi

1. Create a CloudVNO account and provision a US phone number
2. In Vapi dashboard → Phone Numbers → Buy Number → Import
3. Select SIP Trunk and enter CloudVNO credentials from your dashboard
4. Assign your assistant to the number

Full Vapi integration guide →

Getting Started with Retell

1. Provision a CloudVNO number via API
2. Set voice_url to your Retell SIP endpoint
3. Calls automatically route to your Retell agent

Full Retell integration guide →