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

# General SIP Guide for AI Enablement

> Learn how to configure SIP for both inbound and outbound calls with Vida AI phone agents.

SIP (Session Initiation Protocol) is the dominant protocol used globally for VoIP communications, and Vida's AI agent platform natively supports SIP registrations as well as inbound and outbound calls via SIP.

## Configuring a SIP Registration

SIP Registration allows your Vida AI agent to register to an external PBX or SIP server, enabling it to send and receive calls just like any other VoIP device within your network. This is by far the easiest way to connect your agent to your PBX.

Your agent can use your SIP registration via the [Call Transfer](https://vida.io/docs/functions/call-transfer) function to send calls out via your SIP registration so it can dial extensions and other internal destinations. You simply need to prepend `pbx:` or `ext:` to your transfer destination.

Full details on SIP Registration configuration [can be found here](https://vida.io/docs/sip/sip-registration).

## Configuring SIP for Inbound Calls

Before your Vida agent can accept a call over SIP, you need to configure your **SIP IP Access List**.

### Adding IPs to the SIP IP Access List

You can add IPs via the [API](/api-reference/sip/list-sip-ip-whitelist) or through the [Settings -> Developer page](https://vida.io/app/inbox?filter=priority\&settings=true\&showOrgSettings=true\&settingsTab=developers) in your Vida account.

Make sure all IPs sending SIP INVITEs are included in the access list, or calls will not be received by your agent.

![SIP IP Access List Configuration](https://vidapublic.s3.us-east-2.amazonaws.com/vida-sip-access-list.png "SIP IP Access List Configuration")

### Your Agent's SIP URI

Every Vida agent has a unique SIP URI for receiving calls. You can use either the agent's username or phone number in the URI format:

* **Username example**: `sip:vidasales@sip.vida.dev`
* **Phone number example**: `sip:+18335888432@sip.vida.dev`

Replace `vidasales` with your agent's username or `+18335888432` with your agent's phone number. Send SIP INVITEs to this URI from any VoIP PBX or softphone.

**Important Note**: The SIP `From` header must contain a valid E.164 phone number. Using any other format will result in a SIP 404 error.

***

## Configuring SIP for Outbound Calls

To enable outbound SIP calls, configure your **SIP Outbound Routes** in the Vida platform.

### Adding SIP Outbound Routes

You can add outbound routes via the [API](https://vida.io/docs/api-reference/sip/add-sip-outbound-route) or through the [Settings -> Developer page](https://vida.io/app/inbox?filter=priority\&settings=true\&showOrgSettings=true\&settingsTab=developers).

![SIP Outbound Route Configuration](https://vidapublic.s3.us-east-2.amazonaws.com/vida-sip-outbound-routes.png "SIP Outbound Route Configuration")

### Format of the SIP Outbound Route

The general format for SIP Outbound Routes is as follows:

`{Domain or IP}:{SIP Port};transport={tcp or udp};proxyAddress={domain or IP}:{proxy port}`

#### Parameters

* **Domain or IP** (Required): The SIP domain or IP where calls are sent. Supports SIP SRV or A records. This value is used in the Request URI and `To` header host portions.
* **SIP Port** (Optional): The port used for the SIP request. Defaults to `5060` if not specified.
* **Transport** (Optional): Specify `tcp` or `udp`. Defaults to `udp` if not specified.
* **Proxy Address** (Optional): If provided, requests are routed through this address. Supports SIP SRV or A records. The default port is `5060`.

#### Examples

1. Sending to a SIP domain with default settings: `sip.example.com`
2. Sending to a SIP domain using TCP on port 6000: `sip.example.com:6000;transport=tcp`
3. Sending through a SIP proxy using UDP on port 5060: `sip.example.com;proxyAddress=proxy.example.com`
4. Sending through a SIP proxy using TCP on port 6000: `sip.example.com;transport=tcp;proxyAddress=proxy.example.com:6000`

## Summary

Vida’s AI agent platform supports both inbound and outbound SIP configurations. By setting up your **SIP IP Access List** for inbound calls and defining **SIP Outbound Routes**, you can seamlessly integrate your VoIP system with Vida agents. Use the provided examples and ensure your settings match your specific requirements for successful call routing.