# Telnyx Wireless: VoLTE — Full Documentation
> Complete page content for VoLTE (Wireless section) of the Telnyx developer docs (https://developers.telnyx.com).
> Root index: https://developers.telnyx.com/llms.txt · Lightweight index for this subsection: https://telnyx.com/llms/wireless/volte.txt

## Overview

### Overview

> Source: https://developers.telnyx.com/docs/iot-sim/voice-enabled-iot.md

**Beta** — VoLTE is in beta. API reference and detailed configuration docs coming soon.

Add a real phone number to any eSIM-capable device. No second phone, no SIP client, no app — just a native cellular line with full API control.

---

## Configuration

### Phone Numbers

> Source: https://developers.telnyx.com/docs/iot-sim/mobile-phone-numbers.md

When you enable voice on a SIM, Telnyx assigns a Mobile Phone Number — a real +E.164 number. Inbound calls ring the device natively. Outbound calls show your number as caller ID.

## Enabling Voice

Voice is enabled per-SIM via action endpoints, not by patching a field.

| Action | Endpoint |
|:-------|:---------|
| [Enable Voice](/api-reference/sim-cards/request-a-sim-card-enable) | `POST /sim_cards/{id}/actions/enable_voice` |
| [Disable Voice](/api-reference/sim-cards/request-a-sim-card-disable) | `POST /sim_cards/{id}/actions/disable_voice` |
| [Bulk Enable Voice](/api-reference/sim-cards/request-bulk-enabling-voice-on-sim-cards) | `POST /sim_cards/actions/bulk_enable_voice` |
| [Bulk Disable Voice](/api-reference/sim-cards/request-bulk-disabling-voice-on-sim-cards) | `POST /sim_cards/actions/bulk_disable_voice` |

`enable_voice` accepts an optional `connection_id` to associate with a Mobile Voice Connection.

## Mobile Phone Number

Once voice is enabled, manage the assigned number via:

| Action | Endpoint |
|:-------|:---------|
| [List Numbers](/api-reference/mobile-phone-numbers/list-mobile-phone-numbers) | `GET /mobile_phone_numbers` |
| [Get Number](/api-reference/mobile-phone-numbers/retrieve-a-mobile-phone-number) | `GET /mobile_phone_numbers/{id}` |
| [Update Number](/api-reference/mobile-phone-numbers/update-a-mobile-phone-number) | `PATCH /mobile_phone_numbers/{id}` |

### Configurable Settings

| Setting | Description |
|:--------|:------------|
| `call_forwarding` | Forward calls on no-answer, busy, or unconditional |
| `call_recording` | Record inbound, outbound, or both |
| `caller_id_name_enabled` | Enable CNAM lookup on outbound calls |
| `cnam_listing` | Register business name for inbound CNAM display |
| `noise_suppression` | AI noise reduction on calls |
| `inbound_call_screening` | Filter inbound calls before connecting |
| `connection_id` | Associate with a Mobile Voice Connection |
| `customer_reference` | Your own reference string |
| `tags` | Arbitrary tags for filtering |
| `inbound` / `outbound` | Routing configuration per direction |

## Mobile Voice Connection

The voice application attached to a number — controls webhooks, API version, and routing.

| Action | Endpoint |
|:-------|:---------|
| [List Connections](/api-reference/mobile-phone-numbers/list-mobile-voice-connections) | `GET /mobile_voice_connections` |
| [Create Connection](/api-reference/mobile-phone-numbers/create-a-mobile-voice-connection) | `POST /mobile_voice_connections` |
| [Get Connection](/api-reference/mobile-phone-numbers/retrieve-a-mobile-voice-connection) | `GET /mobile_voice_connections/{id}` |
| [Update Connection](/api-reference/mobile-phone-numbers/update-a-mobile-voice-connection) | `PATCH /mobile_voice_connections/{id}` |
| [Delete Connection](/api-reference/mobile-phone-numbers/delete-a-mobile-voice-connection) | `DELETE /mobile_voice_connections/{id}` |

### Connection Settings

| Setting | Description |
|:--------|:------------|
| `webhook_event_url` | Where call events are sent |
| `webhook_event_failover_url` | Backup URL if primary fails |
| `webhook_timeout_secs` | How long to wait for webhook response |
| `outbound` / `inbound` | Routing configuration per direction |
| `active` | Whether the connection is active |

---

### Forwarding, Recording & Screening

> Source: https://developers.telnyx.com/docs/iot-sim/call-forwarding-recording.md

All settings below are configured via [`PATCH /mobile_phone_numbers/{id}`](/api-reference/mobile-phone-numbers/update-a-mobile-phone-number).

## Call Forwarding

Set the `call_forwarding` object to route calls when the device is unavailable.

| Type | Behavior |
|:-----|:---------|
| `unconditional` | All calls forward immediately — device never rings |
| `no_answer` | Forward after timeout (device rings first) |
| `busy` | Forward when line is in use |

Forward to any number — landline, mobile, SIP connection, or Call Control application.

## Call Recording

Set `call_recording` to record inbound, outbound, or both.

Recordings are accessible through the standard Telnyx Recordings API — same storage, retrieval, and webhooks as Call Control recordings.

## Inbound Call Screening

Inbound Call Screening automatically blocks or flags inbound calls based on caller reputation and SHAKEN/STIR attestation. The feature is free on any number.

### How it works

Screening evaluates three factors:

| Factor | Description |
|:-------|:------------|
| **Number Reputation** | Cross-references caller identity against CallerAPI, Nomorobo, and YouMail databases |
| **Number Validation** | Checks whether the originating number is valid and exists |
| **SHAKEN/STIR Attestation** | Validates Caller ID authenticity — screens calls with Attestation C (unauthenticated) or Invalid (certificate error) |

### Handling modes

| Mode | Behavior |
|:-----|:---------|
| **Flag** | Call connects but displays "SPAM LIKELY" in the From and P-Asserted-ID headers. A custom SIP header carries the screening status for your routing logic. |
| **Reject** | Call is blocked at the network level and never reaches your infrastructure. |

### Enabling call screening

1. Log in to the [Mission Control Portal](https://portal.telnyx.com).
2. Go to **My Numbers**, select a number, and click **Edit**.
3. Under the **Voice** tab, enable **Inbound Call Screening** and choose Flag or Reject.

You can also enable it via `PATCH /mobile_phone_numbers/{id}` by setting the `inbound_call_screening` field.

### Webhook integration

Enable webhooks to receive the `call_screening_result` field in the `call.initiated` webhook payload.

Number reputation screening applies to US and Canada calls. SHAKEN/STIR screening applies to North America.

## Other Settings

| Setting | Description |
|:--------|:------------|
| `noise_suppression` | AI noise reduction for loud environments |

## Example

```json
{
  "call_forwarding": {
    "forwarding_type": "no_answer",
    "forwarding_number": "+15551234567",
    "timeout_secs": 30
  },
  "call_recording": {
    "inbound": "enabled",
    "outbound": "disabled"
  },
  "noise_suppression": "enabled"
}
```

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