# Forward Door Phone Calls to an External Number

When a visitor rings the door phone but the person at the indoor monitor is away, on another call, or declines the call, the call would normally go unanswered. To close that gap, set up call forwarding on the extension assigned to the Akuvox indoor monitor. Cloud Voice can then hand the call off to an external number, such as a mobile phone, so someone can still respond.

## Before you begin

- Both Akuvox intercom devices, the door phone and the indoor monitor, must already be connected to Cloud Voice. You can do this by [provisioning the Akuvox intercom devices](/pbx/integrations/akuvox/provision-akuvox-intercom-device-with-cloud-voice-cloud/) or by [registering them manually](/pbx/integrations/akuvox/manually-register-akuvox-intercom-device-with-cloud-voice/).
- The extension registered on the indoor monitor needs permission to dial the external number through the appropriate outbound route.

## Choose a forwarding condition

You can forward door phone calls under either of these conditions, and you can configure both if you want full coverage:

- **No Answer**: the call rings the indoor monitor but no one picks up within the ring timeout. See [Forward calls that go unanswered](#forward-calls-that-go-unanswered).
- **When Busy**: the extension user is already on a call or rejects the incoming call. See [Forward calls when the extension is busy](#forward-calls-when-the-extension-is-busy).

## Forward calls that go unanswered

1. Sign in to the PBX (Private Branch Exchange, your phone system) web portal and open **Extension and Trunk > Extension**.
2. Find the extension registered on the Akuvox indoor monitor and click the edit icon ![Edit](/images/pbx/edit.png) next to it.
3. Open the **Presence** tab on the extension configuration page.
4. In the **Call Forwarding** section, set the destination for internal calls:
   a. Select the **No Answer** checkbox.
   b. In the drop-down list next to **No Answer**, choose **External Number** as the destination.
   c. In the **Prefix** field, enter the prefix of the outbound route you want the call to use.

      :::note
      Leave this field blank if the desired outbound route has no outbound dial pattern.
      :::
   d. In the field beside the prefix, enter the external number that should receive the call.

   ![Call forwarding set to an external mobile number on No Answer](/images/pbx/call-forwarding-2-mobile-phone.png)
5. Scroll to the **Ring Timeout (s)** section and use the **Ring Timeout** drop-down list to set how long the monitor rings before the call is forwarded.

   ![Ring timeout drop-down for the extension](/images/pbx/ring-timeout.png)

   :::tip
   Pick a value that gives someone at the monitor enough time to reach the door, but not so long that the visitor gives up before the call forwards. Around 15 to 20 seconds is a good starting point.
   :::
6. Click **Save**, then **Apply**.

**Result:** When a visitor calls the indoor monitor from the door phone and no one answers within the ring timeout, Cloud Voice forwards the call to the external number you specified.

## Forward calls when the extension is busy

1. Sign in to the PBX web portal and open **Extension and Trunk > Extension**.
2. Find the extension registered on the Akuvox indoor monitor and click the edit icon ![Edit](/images/pbx/edit.png) next to it.
3. Open the **Presence** tab on the extension configuration page.
4. In the **Call Forwarding** section, set the destination for internal calls:
   a. Select the **When Busy** checkbox.
   b. In the drop-down list next to **When Busy**, choose **External Number** as the destination.
   c. In the **Prefix** field, enter the prefix of the outbound route you want the call to use.

      :::note
      Leave this field blank if the desired outbound route has no outbound dial pattern.
      :::
   d. In the field beside the prefix, enter the external number that should receive the call.

   ![Call forwarding set to an external number on When Busy](/images/pbx/call-foewarding-when-busy.png)
5. Open the **Feature** tab, scroll to the **Call** section, and select the checkboxes that match how you want "busy" to be detected:

   ![Feature tab options for busy and reject handling across endpoints](/images/pbx/call-foewarding-all-busy-all-reject.png)

   - **All Busy Mode for Endpoints**: forwards the call to the external number when the extension user is on a call on any one endpoint.
   - **All Reject Mode for Endpoints**: forwards the call to the external number when the extension user rejects it on any one endpoint.

   :::caution
   An extension can be registered on more than one device at once (for example, the indoor monitor plus the Cloud Voice App). If you leave these boxes clear, the extension counts as busy or rejected only when every endpoint is busy or has rejected the call, so **When Busy** forwarding may never trigger. Enable the mode that matches the behavior you want so a single busy or rejected endpoint forwards the call.
   :::
6. Click **Save**, then **Apply**.

**Result:** When a visitor calls the indoor monitor from the door phone and the extension user is already on a call or manually rejects it, Cloud Voice forwards the call to the external number you specified.