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

# Receive calls

> A step by step guide to receive phone calls with Retell managed numbers & imported numbers

### Bind Voice Agents

* Only when you bind agents to a number will the number be able to receive and make calls.
* You can assign different inbound and outbound agent to the number.
* You can leave agent unset to disable inbound / outbound (for example, you are doing outbound and don't
  want callbacks, you can leave `inbound_agent_id` unset)

<Frame caption="Bind inbound and outbound agents to your number">
  <img src="https://mintcdn.com/retellai/rxvYffEkEJPRL1KD/images/deploy/phone-call/bind-agent.jpeg?fit=max&auto=format&n=rxvYffEkEJPRL1KD&q=85&s=e65cbf9714ec24c493ffc4fa914d8772" alt="Phone number configuration showing agent binding for inbound and outbound" width="504" height="296" data-path="images/deploy/phone-call/bind-agent.jpeg" />
</Frame>

After binding an agent for inbound, you should be able to receive inbound calls already.

### A/B Testing

See [A/B Testing](/deploy/ab-testing).

### Inbound Call Webhook

A lot of times, you want to use different agents to handle inbound calls of a number; also you need a way to provide dynamic variables to use for inbound calls, and other fields specific to that call.

Read more at [Inbound Call Webhook](/features/inbound-call-webhook)

### Inbound Custom SIP Headers

* You can use custom SIP headers to pre-set dynamic variables for a call.
* Retell extracts any header starting with `sip.h.x-`, along with common SIP headers like `Diversion`, `History-Info`, `User-To-User` and `P-Asserted-Identity`, and converts each into a dynamic variable by stripping the `sip.h.` prefix.
  * E.g. `sip.h.x-caller: abc` -> `x-caller: abc`
  * E.g. `sip.h.p-asserted-identity: +12345678910` -> `p-asserted-identity: +12345678910`
  * E.g. `sip.h.diversion: <sip:2000@192.168.254.254>;privacy=off;reason=no-answer;counter=1;screen=no` -> `diversion: <sip:2000@192.168.254.254>;privacy=off;reason=no-answer;counter=1;screen=no`

### Get Call Detail

* API: You can use [Get Call API](/api-references/get-call) to get information like
  transcript, recording, latency tracking, etc.
* Webhook: You can also setup webhooks to receive real time updates when call is
  initiated, ends, and analyzed.
  Read more at [Call Webhook Guide](/features/webhook-overview#event-types).