18.4.5 Ensure 'MSS: (KeepAliveTime) How often keep-alive packets are sent in milliseconds' is set to 'Enabled: 300,000 or 5 minutes'
Information
This value controls how often TCP attempts to verify that an idle connection is still intact by sending a keep-alive packet. If the remote computer is still reachable, it acknowledges the keep-alive packet.
Solution
Make sure 'MSS: (KeepAliveTime) is enabled and set to 300,000 or 5 minutes.'