# Introduction

Indian phone numbers and SIP trunks for calling and voice-AI teams.

Vonyx gives you Indian `+91` numbers and a SIP trunk to call through them. Point any SIP client at Vonyx, or place calls with the Call API and stream the audio to your agent over a WebSocket.

## Two ways to connect

<Cards>
  <Card title="SIP trunk" href="/docs/sip">
    Your PBX, dialer or voice platform sends calls to Vonyx with a username and password.
  </Card>
  <Card title="Call API" href="/docs/call-api">
    One HTTP request places a call and streams its audio to your WebSocket.
  </Card>
</Cards>

## How a call flows

```text
Your dialer ──INVITE──▶ Vonyx ──▶ Carrier ──▶ +91 phone
            ◀─200 OK──        ◀──────────── answered
            ◀════════════ audio (RTP) ════════════▶
```

## Where to start

<Cards>
  <Card title="Quickstart" href="/docs/quickstart" description="Verify, buy a number, create a trunk, call." />
  <Card title="Integrations" href="/docs/integrations" description="Step-by-step guides for PBXs and voice-AI platforms." />
</Cards>