To allow the Application Server to clean up abandoned sessions, set enableTimeout to true in the Application Server web.config file. Do not set enableTimeout to true if you want the Application Server to maintain sessions during periods of inactivity.
When timeout is enabled, the Application Server checks for inactive sessions using the timeout period specified in the sessionState element. The timeout period is approximate. Five minutes are added to the timeout value to calculate the timeout interval. The timer that is used to check for inactive sessions runs at half of the calculated timeout interval. Depending on when the timer last ran, an inactive session could remain for up to one and a half times longer than the configured timeout value. Therefore, if the timeout value is set to 15 minutes, the timer will run every 10 minutes, and a session will be cleaned up between 20 and 30 minutes of inactivity.
The minimum timeout value permitted for the Application Server is 10 minutes.
The Application Server's timeout value should never be less than the timeout value specified in the Web Server's web.config.