Change the UM dial plan in Exchange Server

Applies to: Exchange Server 2013, Exchange Server 2016

You may need to move a user who is enabled for Unified Messaging (UM) to a different UM dial plan or change the dial plan that's associated with the user. For example, you might want to move a UM-enabled user from a Telephone Extension dial plan to a SIP URI dial plan.

To change the UM dial plan, you'll have to disable the user for Unified Messaging and then enable the user for Unified Messaging on the new UM dial plan. This is because different dial plans may have different settings and requirements, such as different extension lengths or different URI types. For example, SIP URI dial plans require a SIP Resource Identifier to be assigned to each UM-enabled mailbox, but Telephone Extension dial plans don't. Also, each UM mailbox contains references to both the UM dial plan and the UM mailbox policy. The UM mailbox policy, in turn, contains references to the UM dial plan. If you change the primary proxy address for a UM-enabled user to point to a different dial plan, the UM mailbox is in an inconsistent state.

For additional management tasks related to users who are enabled for voice mail, see Voice mail-enabled user procedures.

What do you need to know before you begin?

Tip

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Step 1: Create the new UM dial plan

Important

If you're migrating UM-enabled users to Microsoft Office Communications Server 2007 R2 or to Microsoft Lync Server, you must first create a SIP URI dial plan.

For detailed instructions, see Create a UM dial plan.

Step 2: Disable the user for Unified Messaging

For detailed instructions, see Disable voice mail for a user.

Step 3: Enable the user for Unified Messaging on the new UM dial plan

Important

If you're moving users to an environment with Office Communications Server 2007 R2 or Lync Server, you must also include a SIP Resource Identifier for the user when you enable them for UM. You must also select the UM mailbox policy that's associated with a SIP dial plan.

For detailed instructions, see Enable a user for voice mail.