Presence - Self and Remote

Entities in a Microsoft Lync 2010 subsystem can have up to eight active endpoints at a given time (Multiple Points Of Presence) that can each publish presence information and subscribe to the presence of others.

As can be seen in the following illustration, Alicia can be logged into multiple devices at the same time. These devices might include an Microsoft Lync 2010 endpoint, and a Microsoft Lync 2010 Phone Edition for Polycom CX700 device, as well as presence from a mobile device. Each endpoint updates her presence information in Lync Server 2010. Upon receiving an update, the server determines whether and which of the endpoint owner’s subscribers should be informed of this change and notifies them accordingly. In addition, all of Alicia’s other endpoints are informed as well if they choose to receive the information.

In Microsoft Unified Communications Managed API (UCMA) 3.0, applications can be developed to support a fully functional endpoint with presence functionalities. The primary presence functions and the related classes are described in this topic.

Publishing Presence

The primary entry point for managing the endpoint owner’s presence is the LocalOwnerPresence property on the endpoint. This property provides access to a LocalOwnerPresence instance, whose members can be used to carry out such tasks as publishing presence, managing relationship levels with subscribers, and acknowledging subscription requests from remote presentities.

An application can also enable presence at the time an endpoint is established. The PresenceServices property on an endpoint provides access to a simplified API that can be used at that time.

For more information, see LocalOwnerPresence.

Subscribing to Remote Presence

An endpoint can discover the presence information of another Lync 2010 presentity by using an instance of the RemotePresenceView class. The mode of subscription (persistent versus polled) can be set, as well as the frequency of updates for a polled subscription. Developers can specify the subscription mode for an endpoint, choosing between subscribing for changes in presence in real time or receiving updates by polling at regular intervals, and can also choose, in some cases, the nature of the data to be received.

An endpoint can also make one-time presence queries.

For more information, see RemotePresenceView.