> ## Documentation Index
> Fetch the complete documentation index at: https://docs.subverseai.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Voice Channel

> Connect inbound and outbound phone numbers to your Voice Agents via SIP trunks

## Overview

A Voice Channel connects your Voice Agent to real phone numbers using SIP trunks. Subverse gives you a unique **SIP URI** for your workspace — you configure your telephony provider to point calls to this URI, and Subverse routes them to the linked agent.

Voice channels support two trunk types:

* **Inbound SIP Trunk** — receives incoming calls and routes them to a Voice Agent
* **Outbound SIP Trunk** — provides a number the agent uses to make outgoing calls

<img style={{ borderRadius: '0.5rem' }} src="https://mintcdn.com/subverse-611dde60/Zexg3flUqmmV-dK_/images/communication-channels/add-voice-channel-sip-trunk.png?fit=max&auto=format&n=Zexg3flUqmmV-dK_&q=85&s=6425dc3da2f084ba9451b9988085dc28" width="1312" height="1002" data-path="images/communication-channels/add-voice-channel-sip-trunk.png" />

Your workspace **SIP URI** is shown at the top of the Voice Channel setup screen. Copy this and configure it as the destination in your telephony provider (Twilio, Telnyx, Plivo, etc.).

<Note>
  To use the live call transfer feature, you must configure an Outbound Trunk for the corresponding number and ensure outbound calling is enabled by your telephony provider.
</Note>

***

## Inbound SIP Trunk

An inbound trunk assigns a phone number that customers can call. Incoming calls on this number are routed directly to the linked Voice Agent.

<img style={{ borderRadius: '0.5rem' }} src="https://mintcdn.com/subverse-611dde60/Zexg3flUqmmV-dK_/images/communication-channels/add-inbound-sip-trunk.png?fit=max&auto=format&n=Zexg3flUqmmV-dK_&q=85&s=6ba048b460d107178ac984fc3ce403c7" width="1166" height="1496" data-path="images/communication-channels/add-inbound-sip-trunk.png" />

### Configuration

| Field          | Type              | Required | Description                                                                                                              |
| -------------- | ----------------- | -------- | ------------------------------------------------------------------------------------------------------------------------ |
| Name           | Text              | Yes      | A friendly name for this inbound trunk (e.g. `Support Line`).                                                            |
| Description    | Text              | No       | Internal description for this channel.                                                                                   |
| Numbers        | Phone number list | Yes      | One or more phone numbers that will receive inbound calls. Click **+ Add number** to add numbers with country code.      |
| SIP Credential | Dropdown          | Yes      | Select a saved SIP credential to authenticate this trunk. Click **Create new credentials** to add one under Credentials. |
| Agent          | Dropdown          | No       | The Voice Agent to handle calls on this trunk. Link directly here or configure it later.                                 |

### How to Set Up

1. Navigate to **Channels** and click **Add Channel → Voice**.
2. Select **Inbound SIP Trunk for Calls**.
3. Enter a **Name** and optionally a **Description**.
4. Add the **phone number(s)** that will receive calls.
5. Select a **SIP Credential** (or create one).
6. Under **Agent Configuration**, select the Voice Agent to handle calls.
7. Click **Save**.
8. In your telephony provider, point the number's SIP destination to your workspace **SIP URI**.

***

## Outbound SIP Trunk

An outbound trunk provides a phone number the Voice Agent uses when placing outgoing calls — either for outbound campaigns or for the test call feature.

<img style={{ borderRadius: '0.5rem' }} src="https://mintcdn.com/subverse-611dde60/Zexg3flUqmmV-dK_/images/communication-channels/add-outbound-sip-trunk.png?fit=max&auto=format&n=Zexg3flUqmmV-dK_&q=85&s=77422319608e8bc1272e76e9b84f29a6" width="1190" height="1404" data-path="images/communication-channels/add-outbound-sip-trunk.png" />

### Configuration

| Field          | Type              | Required | Description                                                                                                            |
| -------------- | ----------------- | -------- | ---------------------------------------------------------------------------------------------------------------------- |
| Name           | Text              | Yes      | A friendly name for this outbound trunk (e.g. `Outbound Dialer`).                                                      |
| Description    | Text              | No       | Internal description for this channel.                                                                                 |
| Numbers        | Phone number list | Yes      | The phone number(s) used as the caller ID for outbound calls. Click **+ Add number** to add numbers with country code. |
| SIP Credential | Dropdown          | Yes      | Select a saved SIP credential authorizing outbound calls. Click **Create new credentials** to add one.                 |

### How to Set Up

1. Navigate to **Channels** and click **Add Channel → Voice**.
2. Select **Outbound SIP Trunk for Calls**.
3. Enter a **Name** and optionally a **Description**.
4. Add the **phone number(s)** to use as the outbound caller ID.
5. Select a **SIP Credential** (or create one).
6. Click **Save**.

***

## Credentials

Voice channels use **SIP Credentials** to authenticate your SIP trunk. These are stored securely in encrypted form and never exposed in plaintext after saving.

<CardGroup cols={2}>
  <Card title="SIP Credentials" icon="key" href="/credentials/types/sip-credentials">
    Create and manage SIP credentials for your voice trunks
  </Card>

  <Card title="All Credentials" icon="shield" href="/credentials/overview">
    Overview of all credential types in Subverse
  </Card>
</CardGroup>

<Tip>
  Need to set up a telephony provider? See the integration guides for [Twilio](/integrations/telephony-twilio), [Telnyx](/integrations/telephony-telnyx), and [Plivo](/integrations/telephony-plivo).
</Tip>