Office Communications Server 2007 offers a competitive VoIP solution to the market. Although its feature set does not rival the feature set provided by most PBX vendors' solutions, Office Communications Server 2007 provides the necessary features to enable the core telephony scenarios most used by users. With the availability of the user's presence information, Office Communications Server 2007 provides novel features that integrate telephony with presence.

Enterprise Voice can be integrated to leverage an organization's PBX that is compatible with Office Communications Server 2007. This integration allows calls to be forked to both Office Communications Server clients (Office Communicator, Office Communicator Mobile Edition) and PBX phones. Alternatively, if Enterprise Voice is not an option for an organization, RCC can be enabled with Office Communications Server to allow Office Communicator to control users' desktop PBX phones.

Table 1-3 provides a breakdown of the features available to contrast each configuration.