Microsoft Office Communications Server 2007 is an enterprise server product that combines corporate instant messaging (IM), presence, federation, conferencing, and telephony (Voice over IP, or VoIP) in a fully integrated unified communications solution. It can integrate with existing Private Branch eXchange (PBX) infrastructure to leverage the investment in communications already made by organizations.
Office Communications Server 2007 is available in two editions, Standard Edition and Enterprise Edition. The Standard Edition Server is a single-server configuration, whereas the Enterprise Edition pool is a multiserver configuration that provides the same functionality as the Standard Edition Server with higher scalability and reliability. An Enterprise pool splits the different Office Communications Server roles onto separate physical servers. These server roles are as follows:
There are two possible configurations for the Enterprise pool: the consolidated configuration and the expanded configuration. The Enterprise pool expanded configuration provides the highest scalability option. It also has the highest deployment cost because it requires the largest number of physical servers.
To enable Office Communications Server 2007 telephony, a Mediation Server, which is an Office Communications Server role, might be required to function as an intermediate between Office Communications Servers and the media gateway. If the enterprise is integrating Office Communications Server with an existing PBX infrastructure, the media gateway should be connected to the PBX. (See Figure 1-1.)
Organizations can also enable remote access for their users and federation with other organizations that have deployed Office Communications Server 2007. To configure Office Communications Server for remote access and federation, a deployment must include the following server roles in the perimeter network:
Access Edge Server This server role is required to allow IM only across the firewall. If allowing audio/video and Web conferencing across the firewall, the Access Edge Server is also required in addition to the other Edge Server roles.
Web Conferencing Edge Server This server role is required to allow Web Conferencing across the firewall.
A/V Edge Server This server role is required for audio and video to work across the firewall.
Office Communications Server 2007 is the next iteration of a Microsoft product line that began with Live Communications Server 2003, 2005, and Service Pack 1 (SP1).
Live Communications Server 2003 introduced the availability of presence information that is updated automatically instead of requiring users to constantly update their status manually. This presence information was updated based on a variety of information, including user activity on the computer and calendar information from Microsoft Office Outlook. Live Communications Server 2003 also introduced corporate IM as a real-time means of communication. Presence and IM were incorporated into all of Microsoft's Office Suite, making them readily available to information workers.
Live Communications Server 2005 SP1 expanded on the functionality offered by Live Communications Server 2003. Remote access, federation, and public IM connectivity (PIC) became available. Integration with PBXs allowed Office Communicator 2005 to control the user's PBX phone. This functionality is referred to as Remote Call Control (RCC). Phone activity was integrated into the user's presence so that it was possible to tell whether the user was on the phone.
This present version, Office Communications Server 2007, introduces a large set of new features since the last release, Live Communications Server 2005 SP1, where Instant Messaging was the only mode of communication supported. In particular, Office Communications Server 2007 introduces support for the following additional modes of communication, also referred to as modalities:
IM Conferencing Two or more users can participate in the same Instant Messaging session.
Web Conferencing Two or more users can collaborate on the same document or application in real time or on a whiteboard.
Audio/Video Conferencing Two or more users can share a video session along with audio or just an audio conference.
Enterprise Voice Users can call phone numbers of other internal users or external users over the Public Switched Telephone Network (PSTN).
These new features and additional capabilities of Office Communications Server 2007 are discussed further in their corresponding sections found later in this chapter.
In addition to the new capabilities just listed, the presence model introduced in Live Communications Server 2003 has also been substantially overhauled in Office Communications Server 2007 to provide a more granular permission model for users to control the level of access that is visible to contacts. This enhanced presence model is discussed in the next section.
Finally, accompanying this lineup of Unified Communications (UC) products is the availability of the UC software developer kit (SDK). The SDKs available for customizing the platform are described in the Customizing the Platform section near the end of this chapter.