Enables the owner endpoint to subscribe to the presence of other unified communications entities identified by their SIP URIs.
Assembly: Microsoft.Rtc.Collaboration (in Microsoft.Rtc.Collaboration.dll)
The unified communications entity being subscribed to can be in the same pool as the endpoint owner, another pool in the same forest, a Public Cloud entity (such as MSN/Yahoo/AOL user), or a Microsoft Lync 2010 user. Subscriptions to these users are handled differently, the. details of which are hidden from the application. All subscriptions to the same server are batched onto a single subscription for better performance. Thus, manages many subscriptions to different servers in an opaque manner.
Applications are notified of subscription failures by the PresenceSubscriptionStateChanged event.
By default, the presence categories subscribed to are "note", "state", "contactCard", "services" and "calendarData". However the application can change this by setting the PresenceSubscriptionCategories property appropriately.
One off presence queries can also be made to SIP URIs without fully subscribing to a unified communications entity by using the BeginPresenceQuery(IEnumerable<String>, , EventHandler<RemotePresenceNotificationEventArgs>, AsyncCallback, Object) method.