Sets how often SSG checks whether a logged-in subscriber's host is still reachable, as part of the Auto Logoff feature. This value is the tradeoff dial between how quickly dead sessions get cleaned up and how much extra probe traffic and CPU load the check itself generates; too short an interval on a large subscriber base can become a load problem in its own right, while too long a one leaves stale, billed sessions around longer. On a network with tens of thousands of subscribers, an admin might set cssgCfgAutoLogOffInterval to 300 (5 minutes) so a subscriber who unplugs their modem is logged off within roughly five minutes instead of triggering a probe storm every few seconds.