How to Change the Audio Codec on a Unified Messaging Dial Plan

Microsoft Exchange Server 2007 will reach end of support on April 11, 2017. To stay supported, you will need to upgrade. For more information, see Resources to help you upgrade your Office 2007 servers and clients.


Applies to: Exchange Server 2007, Exchange Server 2007 SP1, Exchange Server 2007 SP2, Exchange Server 2007 SP3

Topic Last Modified: 2016-11-10

This topic explains how to use the Exchange Management Console and the Exchange Management Shell to change the audio codec on a UM dial plan. Unified Messaging (UM) can use one of three codecs for creating voice messages: Windows Media Audio (WMA), Group System Mobile (GSM) 06.10, and G.711 Pulse Code Modulation (PCM) Linear. By default, when you create a Unified Messaging dial plan, the UM dial plan uses the WMA audio codec. However, after the UM dial plan is created, you can configure the UM dial plan to use the GSM 06.10 or G.711 PCM Linear audio codecs.

On 64-bit Unified Messaging servers, you must install the Windows Media Encoder if you plan to use the WMA UM dial plan codec. For more information about how to install the Windows Media Encoder, see Availability of the Windows Media Audio 9 Voice codec for x64-based computers or visit the Microsoft Download Center.

To perform this procedure, the account you use must be delegated the Exchange Organization Administrator role.

For more information about permissions, delegating roles, and the rights that are required to administer Microsoft Exchange Server 2007, see Permission Considerations.

Also, before you perform these procedures, confirm that a UM dial plan has been created.

  1. In the console tree of the Exchange Management Console, expand the Organization Configuration node.

  2. In the console tree, click Unified Messaging.

  3. In the work pane, on the UM Dial Plans tab, select the UM dial plan that you want to modify.

  4. In the action pane, click Properties.

  5. On the dial plan properties page, click the Settings tab.

  6. On the Settings tab, use the Audio codec list to select the audio codec that you want.

  7. Click OK to accept your changes.

  • Run the following command:

    Set-UMDialPlan -Identity MyUMDialPlan -AudioCodec G711

For more information about syntax and parameters, see Set-UMDialplan.