Custom prompt publishing is the process by which custom audio files are made available to all Outlook Voice Access users and callers who dial in to UM auto attendants. After you have created a custom audio prompt, you must first copy the custom prompt to the Unified Messaging server that you have designated as the prompt publishing point. The prompt publishing point is a shared folder that is located on the first server to be associated with a single UM dial plan. After the custom audio file is copied to the prompt publishing point, all the Unified Messaging servers that are members of the same dial plan will copy the custom audio prompt to a local folder. By copying the custom audio file to a local folder, the Unified Messaging server or servers will be able to play the custom file for Outlook Voice Access users or when callers dial in to a UM auto attendant.

The UM custom prompts that exist in the prompt publishing point will be copied locally by a Unified Messaging server regardless of the number of Unified Messaging servers that belong to the UM dial plan. Each UM dial plan represents a set of Unified Messaging servers and the set of UM-enabled users for whom the Unified Messaging servers answer incoming calls. Small dial plans that serve hundreds of users or fewer may have only one Unified Messaging server. Large dial plans that have several thousand users or more or that provide redundancy to help maintain UM service availability have two or more Unified Messaging servers.

Publishing custom prompts has the following benefits:

• Consistent user experience   To the user, custom prompts appear to always work in the same manner and at the same speed.
  
• Consistent server configuration   You do not have to make sure that each Unified Messaging server is updated correctly.
  

After you create a single copy of the custom audio file that you want to use as an audio prompt, greeting, or information announcement, you must make sure that all the Unified Messaging servers associated with the UM dial plan receive a copy of this custom audio file. You do this by configuring the UM dial plan or UM auto attendant to use the custom prompt by using the Exchange Management Console or by using the Copy-UMCustomPrompt cmdlet in the Exchange Management Shell.

When you install the Unified Messaging server role, the audio files for the system prompts are copied to a folder on the Unified Messaging server. The system prompts that are copied to the Unified Messaging server are used as the default prompts for UM dial plans and auto attendants. Because the system prompts are generic, you might want to enable custom greetings, announcements, and menu prompts in your Unified Messaging environment. You must first create your custom audio prompts, enable the custom prompts on a UM dial plan or auto attendant, and then make sure that your custom prompts are available on each Unified Messaging server that belongs to a single UM dial plan.

You can use the Exchange Management Console or the Exchange Management Shell to copy the required custom audio files. To make sure that the custom prompts are available to each Unified Messaging server, you perform the following tasks by using the Copy-UMCustomPrompt cmdlet or when you select the custom audio file in the Exchange Management Console:

• Locate the prompt publishing point in the Active Directory directory service.
  
• Copy the custom prompt to the prompt publishing point.
  
• Update the configuration for Unified Messaging in the Active Directory directory service.
  

After these tasks are performed, the Microsoft Exchange File Distribution service updates each Unified Messaging server that is associated with the dial plan.

Figure 1 illustrates the custom prompt publishing architecture and tasks that are performed by the Copy-UMCustomPrompt cmdlet or when you configure the dial plan or auto attendant to use a custom audio file by using the Exchange Management Console.

The Copy-UMCustomPrompt cmdlet queries the appropriate dial plan object in Active Directory to determine the location of the prompt publishing point. There is only one prompt publishing point for each dial plan, and it is stored as a Windows file share (also known as UNC) path that identifies a file share that is available for custom prompts. After the location of the prompt publishing point is determined, the cmdlet validates the content in the custom prompt, verifies that it is in the correct format, and that it uses a supported audio codec. If the custom prompt passes the validation tests, the Exchange Management Shell command copies the prompt content to the prompt publishing point.

The custom audio files in the prompt publishing point are automatically organized into a directory structure that reflects the dial plans and auto attendants that are configured in your Exchange 2007 organization.

Figure 2 illustrates the prompt publishing point directory structure. In Figure 2, a prompt publishing point has various subdirectories that correspond to UM dial plans and. There are auto attendants within each dial plan.

Each UM dial plan and UM auto attendant that is created is given a unique ID. The directory names are generated from the unique IDs that are given to the dial plan or auto attendant when their configuration objects are created. You do not have to know the exact names or locations of files under the prompt publishing point, because the Copy-UMCustomPrompt cmdlet uses the unique ID that is associated with the dial plan or auto attendant to make sure that the custom prompt is copied to the correct location in the directory structure.

After the custom prompt is copied to the prompt publishing point and any necessary directory updates are made, the prompt is copied to each Unified Messaging server in the dial plan. After the custom prompt is added to the appropriate folder on the Unified Messaging server that is configured as the prompt publishing point, the Microsoft Exchange File Distribution service that runs on each Unified Messaging server refers to the prompt publishing point and determines whether the files in the prompt publishing point have changed or if additional files have been added. If files have been changed or additional files exist, the other Unified Messaging servers pull the custom prompts from the prompt publishing point and copy them to the correct location in the \\<Server name>\ExchangeUM folder that exists on a local drive.

All the Microsoft Exchange File Distribution service information is stored in Active Directory. However, you should back up the source locations for replicated files, such as offline address books and UM prompts. The offline address book source is the Mailbox server that generates the offline address book, and the UM prompt location is on the first Unified Messaging server, unless otherwise specified. As long as the source is backed up or restored, the Microsoft Exchange File Distribution service replicates the content. If any of the replica servers go down, Microsoft Exchange File Distribution service replicates content from the source as soon as they are back online without any administrator intervention. You can run Update-FileDistributionService to force replication if you do not want to wait for the automated process to occur.

The prompt publishing point for a UM dial plan is automatically set at the time that the first Unified Messaging server joins the dial plan. It can be located on any server that can be accessed by the Unified Messaging servers that are associated with a particular dial plan. The prompt publishing point is a property that is set on a UM dial plan and is set to \\<server name>\ExchangeUM, where <server name> is replaced by the NetBIOS name of the Unified Messaging server.

For dial plans that have one Unified Messaging server, there is little reason to change the location of the prompt publishing point. However, you may want to move the prompt publishing point for the following reasons:

• In a dial plan that has multiple Unified Messaging servers, the prompt publishing point represents a single point of failure.
  
• A Unified Messaging server generally does not act as a file server. A Unified Messaging server may not be backed up as frequently as other servers and may not be configured to have disk storage devices such as redundant array of independent disks (RAID) arrays. If a file server that has a RAID array exists on the network, you may want to use it for the master copy of the UM custom prompts.
  

  Important:
  You must move the prompt publishing point to another location before you can uninstall the Unified Messaging server role.

For more information about how to change the prompt publishing point, see How to Change the Prompt Publishing Point.

• For more information about Unified Messaging audio prompts, see Understanding Unified Messaging Audio Prompts.
  
• For more information about how to manage Unified Messaging custom audio prompts, see Managing Custom Audio Prompts.