Q. What's the difference between the Microsoft Exchange Server Unified Messaging (UM) role and Microsoft Office Communications Server 2007?

A. Exchange 2007 consists of a number of roles, one of which is the UM role. UM requires separate Client Access Licenses and enables the following additional functionality over standard Exchange:

  • Unified store for email, fax, and voice messaging. The Exchange UM role controls the receipt of voicemail, configuration of answer message, fax receipt, and other functions.

  • Access to a unified store from both a computer and from a phone using voice commands (voice user interface) or numeric key presses (telephone user interface) which collectively are known as Outlook Voice Access. Phone access also includes the ability to search Global Address List, check calendars, accept/reject meetings, and an Auto Attendant is provided to give guidance on feature access.

  • A single management interface for voice, fax, and email platforms with scripting support.

Essentially, the UM role does exactly what the name suggests. It provides the ability to access your voice messages, fax, and email from a single location via computer or phone. The UM can hook directly into many IP PBX telephone systems that serve a specific business or company. Companies using traditional non-IP PBX systems must install a gateway between the PBX and the UM servers to facilitate communication.

OCS 2007 is a separate product from Exchange, but can integrate heavily with Exchange to give a complete communication solution. OCS 2007 focuses on real-time communication while Exchange is primarily a message store. OCS 2007 provides the following features:

  • Secure and archivable IM for an organizations users with connectivity to public IM services such as Yahoo and Windows Live Messenger through Public IM Connectivity (PIC), which is a separate license. OCS can also federate with other organizations' OCS implementations to allow communication via IM with partner companies without the need to use public IM services.

  • Presence information showing if a contact is currently online, busy, in a meeting, or so on. This information is visible in many mediums, including Outlook and SharePoint, and can be used to initiate communication through IM, voice, or a meeting scheduling.

  • File Transfer capabilities.

  • Peer-to-peer and multiparty conferencing services, including voice and video with web accessibility. Live Meeting client is used to access the services or the web-based interface.

  • Voice services allowing outbound and inbound voice conversations with redirection of incoming calls to alternate numbers (voice call routing).

  • A software based VoIP solution (Enterprise Voice).

  • 2007 R2 also adds support for desktop sharing, call management (allowing receptionists to take incoming calls then route to recipients) and group chat, which allow persistent chat rooms to be created which can be accessible to federated partners for cross-organization communication.

OCS has a client, Office Communicator, which is installed on users' desktops as the main interface to OCS. Office Communicator Mobile is available for mobile devices, giving access to OCS functionality, and Office Communicator Web Access, a web-based portal is also available.

When you combine Exchange 2007, Exchange 2007 UM, and OCS, you have a Unified Communications solution which gives single store access to all your e-mail, fax, and voice messages. You also have a rich interface for real-time communication, whether it be voice, text, video, or meeting-based, with presence information available to help choose the best way to contact people. The traditional divide between your phone system and your computer-based solutions is removed with UC.

Related Reading:
Check out hundreds more useful Q&As like this in John Savill's FAQ for Windows. Also, watch instructional videos made by John at ITTV.net.
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