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

# Incoming Calls

> The Volubile platform allows you to integrate our AI voice agents into your existing phone infrastructure to manage your incoming calls. This page presents the different integration methods available.

### Integration Options

<Tabs>
  <Tab title="Standard Call Forwarding">
    ### Call Forwarding Setup

    This simple yet effective method allows you to quickly redirect your calls to our voice agents.

    1. **Dedicated Number** — Volubile provides you with a unique number dedicated to your organization
    2. **Redirection Setup** — You configure your existing phone systems to forward incoming calls to this number
    3. **Automated Handling** — Our AI voice agents handle all redirected calls according to the configured scenarios

    <Warning>
      This option may incur additional costs associated with call forwarding from your phone infrastructure. These fees vary depending on your current phone provider.
    </Warning>
  </Tab>

  <Tab title="SIP Integration">
    ### SIP Trunking Setup

    This advanced method offers deeper integration and optimal performance for professional environments.

    1. **Prerequisites** — Ensure that the "SIP Trunk" feature is enabled on your Volubile account
    2. **Connection Settings** — Access the SIP credentials in the administration interface:

    ```
    Settings > SIP > SIP Trunk
    ```

    <Frame>
      <img src="https://mintcdn.com/weengage/qT_zmsw8Ut0OGKeg/images/telephony/volubile-telephony-sip-trunk.png?fit=max&auto=format&n=qT_zmsw8Ut0OGKeg&q=85&s=cbbe1c8689f4ee473ce36b9e6ea0652b" width="1864" height="392" data-path="images/telephony/volubile-telephony-sip-trunk.png" />
    </Frame>

    You can configure an authentication method:

    <AccordionGroup>
      <Accordion title="IP Address Authentication">
        * Enter the IP addresses allowed to connect to the SIP trunk
        * You can use CIDR notation to specify address ranges
        * Example: `203.0.113.1` or `203.0.113.0/24`
      </Accordion>

      <Accordion title="Credential Authentication">
        * **Username**: 5 to 32 characters (letters, numbers, hyphens only)
        * **Password**: 12 to 64 characters (must contain at least 1 digit, 1 lowercase letter, and 1 uppercase letter)
        * Case-sensitive
      </Accordion>
    </AccordionGroup>

    3. **Connection Information**:

    In the telephony configuration section of your agent, you will find the essential information to establish the connection with your phone infrastructure.

    <Frame>
      <img src="https://mintcdn.com/weengage/qT_zmsw8Ut0OGKeg/images/telephony/volubile-telephony-sip-agent-fqdn.png?fit=max&auto=format&n=qT_zmsw8Ut0OGKeg&q=85&s=2f92a53fe2529f0af1cfd0e55f789a74" alt="Volubile Agent SIP Configuration" width="2090" height="1414" data-path="images/telephony/volubile-telephony-sip-agent-fqdn.png" />
    </Frame>

    The following parameters are required for configuring your SIP connection:

    * SIP Server Address: The FQDN of our SIP server that your system must connect to <code>Example:
      volubile-efe2e38.sip-eu.vonage.com</code>

    * Agent FQDN Identifier: The unique identifier used to authenticate your agent upon connection <code>Example: 5389079</code>

    4. **Client Configuration** — In your phone infrastructure:

    * Configure the authentication on the SIP trunk according to the chosen method (IP or credentials)
    * Set up the forwarding of incoming calls to our SIP server

    ### SIP headers options

    1. **From header**

    If the caller's number is not correctly transcribed in the platform, it is possible to send it through the SIP header `X-Volubile-System-From` during call setup. This method allows for seamless integration with your existing systems.

    ```text Example theme={null}
    X-Volubile-System-From = +33612345678
    ```

    2. **To header**

    If the recipient agent's number cannot be overridden by your telephony system, as in the case of SIP redirect, you can use the SIP header `X-Volubile-System-To` to specify the Volubile agent's number.

    ```text Example theme={null}
    X-Volubile-System-To = 2566458
    ```

    3. **User-to-User header**

    The SIP `User-to-User` header is supported and always stored as a context variable. Therefore, if your contact center supports the User-to-User header according to RFC 7433, the Volubile agent will store the value as a `user_to_user` context variable.

    4. **Other custom headers**

    If you need to specify other custom information regarding the calling context, you can use header keys with the `X-Volubile` prefix.

    ```text Example theme={null}
    X-Volubile-Store = 'My Custom Store'
    ```

    [See context vars documentation](/en/product/prompt/context#sip)
  </Tab>
</Tabs>