Getting Started with Enhanced Presence
A unified communications application establishes real-time communication between users and identifies the presence of each user. A typical unified communications application publishes presence data to specify availability, activities and supported device capabilities, calendar data, contact information, and other user information. It also needs to support presence subscription for the user to discover the presence information published by other users. Such presence information allows the users to determine when and how to contact each other.
Enhanced presence, as supported in a Microsoft Lync Server 2010 deployment, lets an application developer include any information as part of the presence. It also provides a flexible mechanism for the application developer to publish the presence information in a way that the user controls what presence data is published, who can access the publications, and how much information a subscriber may receive. It does so with a flexible data model to represent many types of presence information, which is also supported by a robust access control mechanism for publishing, subscribing to and querying the enhanced presence.
In a Lync Server 2010 deployment, the enhanced presence schemas are exposed to third-party application developers through various APIs, including Microsoft Unified Communications Managed API (UCMA) 3.0 and Microsoft Lync 2010 SDK. With these APIs, presence data can be created, parsed, and manipulated using supported API objects instead of the raw XML-blobs. In Lync SDK, all the supported presence data is encapsulated. However, UCMA may require the application to explicitly construct or parse some presence data as XML blobs. This is especially true when the application must handle custom presence data.