To create a new UM dial plan, in the New UM Dial Plan Wizard, on the New page, complete the following information:

Dial plan name    

• A UM dial plan name is required and must be unique, but it is used only for display purposes in the Exchange Management Console and the Exchange Management Shell. If you have to change the display name of the dial plan after it has been created, you must first delete the existing UM dial plan and then create another dial plan that has the appropriate name. If your organization uses multiple UM dial plans, we recommend that you use meaningful names for your UM dial plans. The maximum length of a UM dial plan is 64 characters, and it can include spaces. However, it cannot include any of the following characters: " / \ [ ] : ; | = , + * ? < >.
  

Number of digits in extension    

• The number of digits for extension numbers is based on the telephony dial plan that is created on a PBX. For example, if a user associated with a telephony dial plan dials a 4-digit extension to call another user in the same telephony dial plan; you select 4 as the number of digits in the extension. This is a required field that has a value range from 1 to 20. The typical extension length is from 3 to 7. If your existing telephony environment includes extension numbers, you must specify a number of digits that matches the number of digits in those extensions.
  

After you complete the fields on this page of the New UM Dial Plan Wizard, click New to create the new UM dial plan.

For more information about UM dial plans, see the following topics:

• Managing Unified Messaging Dial Plans.
  
• Understanding Unified Messaging Dial Plans.