Forum Discussion
FYI - I found this detail in our documentation of how we configured things differently from the default template settings:
The CAS Array F5 VIPs in each datacenter will be modified to use the RPC persistence profile timeout of 8 hours instead of the F5 default 3 minutes, and the TCP protocol idle timeout (for both WAN and LAN optimized profiles) of 1 hour instead of the F5 default 5 minutes. These changes are necessary to support proper BlackBerry operations and overall MAPI client communications to the CAS Arrays.
If I understand you correctly, neither the "Disabled" or the "Forced Offline" will cause the MAPI sessions to time out after 8 hours, and that essentially as long as the client and server keep the channel open the session will stay active (which explains why we saw sessions 24 hours after we disabled a CAS).
Subsequently there is no effective way to drainstop a CAS from the MAPI CAS Array within the defined timeout period, and that essentially we have to break the client connections to the back end either by deleting them or outright rebooting the server.
If that's all correct, then that sucks as we can't take action in the middle of the day that might cause connection prompts to users as the help desk will get calls.
I appreciate your continued advice and responses.