Loosely Coupled Events
The loosely coupled event model provided by COM+ supports late-bound events or method calls between the publisher and subscriber and the event system. Rather than repeatedly polling the server, the event system notifies interested parties as information becomes available.
To use this service, the event class and the event sink must derive directly or indirectly from the System.EnterpriseServices.ServicedComponent class. For more information about how to implement an event class and event sink, see How to: Implement Loosely Coupled Events.
To create persistent or transient subscriptions between the sink and the event class, use the COM+ administration objects with scripts or managed code. You can also create transient subscriptions using the Component Services administrative tool, accessible from the Windows Control Panel.