# Assign Alternate Extensions to a Single Mailbox

The Alternate Extension feature is used to assign multiple extension numbers to a single mailbox. You can add four more extension fields to the mailbox record for a total of five phone numbers that can be associated with one mailbox. The first extension is the primary extension; the other four are alternate extensions.

## Call Behavior

Call behavior depends on the call scenario. The Receptionist feature and FCOS bit 64 use the primary extension to transfer calls as before. All the extension fields are used by this new feature to match against incoming calling IDs.

The following describes a few call scenarios:

1. Calling from any of the mapped extensions to voice mail is greeted by the login prompt of the mailbox that has the mappings.

2. A call to a teleworker phone that then forwards to voice mail is greeted by the desk phone’s mailbox’s greeting.

3. A call to a cell phone that then forwards to a DID number on the switch that ends up at the desk phone will get ring back while the desk phone is ringing. If the call is not picked up, the desk phone forwards to voice mail and the caller hears the desk phone’s mailbox’s greeting.

4. When an MWI action is instigated, only the set on the switch whose extension matches the mailbox number is affected. This extension may or may not be one of the 5 mapped to the mailbox.

In general, alternative extensions are used for non-desktop telephone numbers (for example, cell phones or teleworker phones). However, the system does not prevent you from associating desktop telephone extensions with the primary mailbox.

## Configuration

Depending on the integration and call scenarios, configuration for this feature can be quite different. However, there are always three common aspects:

- Set configuration

- Switch configuration

- NuPoint Unified Messaging configuration

## Example:

### MiVoice Business ICP Integration – desk phone and teleworker phone

In this scenario, a MiVoice Business ICP user has a desk phone and a teleworker phone. This user would like these two phones to have the same mailbox and get the same voice mail integration with each of the two phones.

Set configuration:

- Configure the teleworker set to forward to the voice mail hunt group. This should be the same as forward configuration for the user's desk phone.

Switch configuration:

- Same as set configuration.

NuPoint configuration:

1. Create a mailbox matching the extension of the user’s desk phone.

2. Set the primary extension to the extension of the user's desk phone (i.e. use the default value).

3. Set the alternate extension #2 to the extension of the user's teleworker phone.
   Assuming that the extensions are of the same length, the extension dial plan of the line group for incoming calls does not have to change. (Otherwise, the flexible ’r;v’ dial plan would have to be used.)

4. Configure the mailbox extensions.

- Managing Mailboxes