In some environments, it is critical that when a user stops using a session, the session is closed to the host. Since it is unreliable to capture a browser being closed (or actually killed with Task Manager), the Lost Session Timeout can be used as a "dead browser detector".
When Lost Session Timeout is set to something other than 0 (zero-the default), that will set the number of minutes that the FVTerm server logic will wait in-between any activity from the client before automatically closing the session.
When websockets are active, a ping is sent every 20 seconds, unless an enter or keystroke has been sent in the meantime. Since there can be delays in the websocket (or plain HTTP environment), the minimum recommended setting for Lost Session Timeout is 2 minutes. 5 minutes probably provides the best balance between network error recovery and user's browsers being closed without ending the session.
