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

# Overview & Setup

> Learn about SIP integration and how to set it up in Callers.

# SIP Integration Overview

SIP (Session Initiation Protocol) integration allows you to connect your existing telephony infrastructure with Callers. You can use SIP for both incoming and outgoing calls:

* **Incoming Calls**: Receive calls from your SIP provider to Callers
* **Outgoing Calls**: Make calls from Callers through your SIP provider
* **Bidirectional**: Use the same numbers for both incoming and outgoing calls

<Note>
  Your SIP provider will need to whitelist our IP address:

  ```copy theme={null}
  35.245.182.192
  ```

  Alternatively, you can use DNS: `sip.callers.ai`

  **Important:** This IP/DNS can only be used for inbound calls to Callers. It cannot be added to your allowed IPs list for receiving outbound calls from us.
</Note>

## Setting Up SIP Integration

### Step 1: Access SIP Integration

* Go to the ***App Center*** tab on your Callers dashboard
* Find SIP under the `TELEPHONY & COMMUNICATION` section
* Click on the `plus` button in the SIP Integration block

{/*     <img src="../../images/documentation/integrations/new-sip-window.png" alt="new sip window" style={{borderRadius: '10px'}} /> */}

<Frame caption="Setup a SIP under Integrations">
  <img src="https://mintcdn.com/voxiaai/uyFxyS8gRtMdGpw9/images/documentation/integrations/connect-sip-button.png?fit=max&auto=format&n=uyFxyS8gRtMdGpw9&q=85&s=0484a34a6c1daa6461c596d6774a0f59" alt="connect sip button" style={{borderRadius: '10px'}} width="2514" height="1119" data-path="images/documentation/integrations/connect-sip-button.png" />
</Frame>

### Step 2: Configure SIP Details

* **SIP Name**: Enter a descriptive name for this SIP connection
* **E.164 syntax:** All phone numbers must use the format: \[+] \[country code] \[area code] \[number]
* **Outbound Authentication Settings:**
  * Enable if your SIP provider requires authentication
  * **Username**: Your SIP authentication username
  * **Password**: Your SIP authentication password
* **Advanced Settings:**
  * **Tech Prefix:** Enable if required by your provider
  * **SIP Diversion Header:** Enable for authenticated outgoing calls
  * **URL**: Your SIP provider's endpoint URL
  * **Port**: Default is 5060 (or as specified by your provider)
* **Gateway Configuration:** Enable to use the same numbers for both incoming and outgoing calls

<Frame caption="Configure your SIP">
  <img src="https://mintcdn.com/voxiaai/uyFxyS8gRtMdGpw9/images/documentation/integrations/configure-sip.png?fit=max&auto=format&n=uyFxyS8gRtMdGpw9&q=85&s=c02954ffb446dad38ceee6c3c049d919" alt="configure sip" style={{borderRadius: '10px'}} width="3251" height="1656" data-path="images/documentation/integrations/configure-sip.png" />
</Frame>

Click `Next` to proceed.

### Step 3: Add Phone Numbers

After the initial setup:

1. You'll be prompted to enter your SIP phone numbers
2. Alternatively, access the `Phone numbers` tab and click `Add SIP Numbers` anytime

## Multiple SIP Connections

You can set up multiple SIP connections to:

* Work with different providers
* Set up redundancy
* Route calls through different providers based on regions or cost

To add another SIP connection:

* Go to the ***Integrations*** tab
* Click `Connect` in the SIP Integration section
* Configure the new connection's details

<Frame caption="Set up additional SIP connections">
  <img src="https://mintcdn.com/voxiaai/uyFxyS8gRtMdGpw9/images/documentation/integrations/multiple-sip.png?fit=max&auto=format&n=uyFxyS8gRtMdGpw9&q=85&s=0878d6fb99e228ae3226cbba206f17a6" alt="multiple sip" style={{borderRadius: '10px'}} width="2795" height="1463" data-path="images/documentation/integrations/multiple-sip.png" />
</Frame>

## Contact Fields in SIP Headers

All contact fields are included in the SIP headers to ensure comprehensive integration and communication. This allows for:

* Seamless data transfer
* Complete call handling information
* Proper call routing
* Support for advanced features like call forwarding

For more details on call forwarding capabilities, see the [Call Forwarding section](../build-your-campaign/customizing-steps#call-forwarding).

## Provider-Specific Guides

For detailed instructions on setting up specific SIP providers, please refer to our integration guides in the sidebar.