Exchange UM Components

The deployment of Exchange Unified Messaging involves the configuration of several internal components, and these must be configured in a specific way to allow for integration with Lync. This section includes a description of these components to provide background on Exchange UM, as well as an explanation as to how the Exchange UM components fit into the picture with Lync and Exchange UM integration.

Following are the components included in an Exchange 2013 UM deployment:

• UM Dial Plan—UM dial plans are the central component of the Exchange unified messaging architecture. A UM dial plan logically corresponds to the set of extensions that are planned and assigned using a PBX. Some additional important purposes of the UM dial plan are that it associates the extension for subscriber access, and it establishes a common set of policies for a group of users, such as number of digits in an extension. Even in an environment where Lync is used for Enterprise Voice and is therefore used to establish the dial plan for the organization, one UM dial plan is still required for Lync to integrate with Exchange UM.

• UM Mailbox Policy—Unified Messaging mailbox policies are used to apply and standardize configuration settings for UM-enabled users. Some of the more important policy settings applied by a Unified Messaging mailbox policy include PIN policies, dialing restrictions, and maximum greeting duration. By default, a single UM mailbox policy is created every time a UM dial plan is created, and is named after the dial plan. The new UM mailbox policy is also automatically associated with the UM dial plan. Although only a single UM mailbox policy is required to enable users for Unified Messaging, additional UM mailbox policies can be created in order to apply a common set of mailbox policy settings for groups of users. The mailbox of each UM-enabled user must be linked to a single UM mailbox policy when the mailbox is enabled for Unified Messaging.

• UM IP Gateway—A Unified Messaging IP gateway object is a container object that logically represents a physical IP gateway hardware device, an IP-PBX, or another SIP server that can interoperate with Exchange Unified Messaging. Before the IP gateway can be used to process UM calls, it must be represented by an object in Active Directory. The combination of the IP Gateway object and a UM hunt group object establishes a logical link between an IP gateway hardware device and a UM dial plan. There can be only one UM IP gateway for each physical IP/VoIP gateway, and this is enforced through IP addresses.

• UM Hunt Group—With Exchange UM, hunt groups are used to act as a link between the UM IP gateway and the UM dial plan. UM hunt groups are used to locate the PBX hunt group from which the incoming call was received. A pilot number that is defined for a hunt group in the PBX must also be defined within the UM Hunt group, and is used to match the information presented for incoming calls through the SIP signaling information on the message. The pilot number enables the Unified Messaging service to interpret the call together with the correct dial plan so that the call can be routed correctly.

• UM Auto Attendant—Unified Messaging auto attendants are used to help internal and external callers locate users or departments that exist in an organization and transfer calls to them. The UM auto attendant is a series of voice prompts or .wav files that callers hear when dialing the organization.