# Configure Call and Door Release for PBX Extensions on the Intercom

After a 2N IP (Internet Protocol) intercom is registered to your PBX (Private Branch Exchange, your phone system), you can direct its call button to specific extensions and enable remote door release. Once this is in place, a visitor's press rings the assigned extensions, and the person who answers can unlock the entrance directly from the Cloud Voice App, without leaving their desk or walking to the door.

## Prerequisites

- You have [created extensions for the indoor receivers](/pbx/integrations/2n-intercom/2n-ip-intercom-integration-preparation/#_2n-ip-intercom-integration-preparation__create-extension-for-indoor) on the PBX.
- You have [set up the network for the 2N IP intercom](/pbx/integrations/2n-intercom/2n-ip-intercom-integration-preparation/#_2n-ip-intercom-integration-preparation__section_q2g_prj_ghc) and [registered a PBX extension on the device](/pbx/integrations/2n-intercom/register-2n-ip-intercom-with-cloud-voice/).

:::note
Finish both prerequisites before you start. The intercom can only place calls after it holds a registered PBX extension, so if registration is not complete the steps below will not work.
:::

## Overview

Setting up call and door release involves three tasks. The first two are required; the third is optional.

1. Configure the call destination.
2. Set the DTMF code for door release.
3. (Optional) Customize the audio prompt for door release.

Complete each task on the web interface of the 2N IP intercom.

:::note
DTMF stands for Dual-Tone Multi-Frequency: the tones a phone produces when you press keys on the keypad. The intercom listens for these tones during a call and releases the door when it hears the code you set.
:::

## Configure the call destination

Tell the intercom which extensions to ring when a visitor presses the call button.

1. Sign in to the 2N IP intercom web interface.
2. Add each person you want to reach, along with their PBX extension:

   a. Go to **Directory > Users** and click **Add User**.

   ![The Add User button on the intercom Users directory page](/images/pbx/2n-add-user.png)

   b. Fill in the following fields:

   - **Name**: A label that identifies the user.
   - **Phone Number**: The user's PBX extension number.

   ![User details showing the Name and Phone Number fields](/images/pbx/2n-users.png)

   :::note
   **Phone Number** here means the internal extension number on your PBX (for example, `1001`), not an external phone number or DID (Direct Inward Dial, a public number that reaches an extension from outside). The intercom dials this extension over the PBX.
   :::

   c. Click **Save** at the bottom right.
3. Link the users to the call button:

   ![The Dialing page where users are assigned to the main unit call button](/images/pbx/2n-set-dial.png)

   a. Go to **Calling > Dialing** and click the add icon ![Add button](/images/pbx/add-macbook.png) under **Main Unit Buttons**.

   b. In the dialog, select the user or users you added, then click **Add**.

   c. Click **Save** at the bottom right.

:::tip
You can assign more than one user to the call button. A single press then rings every assigned extension at once, so a visitor reaches whoever is available first.
:::

## Set the DTMF code for door release

Define the code an extension user enters during a call to open the door.

1. Go to **Hardware > Switches**.

   ![The Switches page under the intercom Hardware menu](/images/pbx/2n-hardware-setting.png)

2. On the **Switch 1** tab, set up the door-release code:

   - Select the **Switch Enabled** checkbox.
   - In **Activation Codes**, enter one or more DTMF codes.

   ![The Switch 1 tab with the Switch Enabled option and Activation Codes field](/images/pbx/2n-switch-code.png)

   :::tip
   If **Switch Enabled** is not selected, the intercom ignores the activation codes and the door will never release. Confirm the checkbox is on before you save.
   :::

   :::caution
   This code controls a physical door lock. Anyone on a call with the intercom who dials the code can unlock the entrance, and the keypad tones can be overheard. Choose a code that is not easy to guess, share it only with people who should have access, and change it if you think it has been exposed.
   :::

3. Click **Save** at the bottom right.

:::caution
The code a user dials during the call must match an entry from **Activation Codes** on the **Switch 1** tab and must be followed by the `*` character. A mismatched code or a missing `*` leaves the door locked. Keep the two ends in sync: if you change the activation code here, tell the extension users the new code.
:::

## (Optional) Customize the audio prompt for door release

Choose the sound the intercom plays when the door is released.

1. Go to **Services > User Sounds**.

   ![The User Sounds page under the intercom Services menu](/images/pbx/2n-service.png)

2. On the **Sound Mapping** tab, pick the sound you want for Switch 1.

   ![The Sound Mapping tab with a sound assigned to Switch 1](/images/pbx/2n-sound.png)

Whenever the door is released with a code from the **Switch 1** tab, the intercom plays the sound you assigned here.

:::note
This step only changes which sound plays at the door. It does not change the activation code or affect whether the door releases.
:::

## Result

- Pressing the call button on the 2N IP intercom places a video call to the extensions you designated.
- Assigned extension users see the video feed and can answer on the Cloud Voice App. To let the visitor in, the user dials a switch code followed by `*` during the call (for example, `00*` or `1234*`). The intercom announces "The door is open, please come in.", confirming the door has unlocked.

:::note
To preview the visitor's video, the answering user needs a video-capable Cloud Voice App (desktop or mobile). Audio-only devices can still answer and open the door with the DTMF code, but will not show the video feed.
:::