Networked applications must deal with a host of connection problems ranging from timeouts to congestion to unavailability. If these applications can check the current connection status and, when disconnected, cache transmissions, they become more efficient. Fortunately, both the System Event Notification System (SENS) and Windows Management Instrumentation (WMI) can send notifications to keep applications informed of network status. In this article, the author explains the use of several SENS interfaces, including ISensNetwork and ISensLogon, which trigger events for connects/disconnects and logons/logoffs, respectively. The author then shows how you can subscribe to each of these events, and follows with a discussion of when you might use WMI events instead.
MSDN Magazine August 2002
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