Assuming the programmed activity switch is active (which on a healthy redundant system, it should be), the newly inactive plane will reset after the activity switch happens. By default this is programmed to happen every day at 2:15am, so assuming the activity switch completes normally, each plane resets every other day. If you need to reload a control plane manually, just log in and do a "load <PLID>" for the MC3E you wish to re-load. If you need to bounce the active plane, do a "activity switch force", but this will knock down any conference calls in progress and any ACD calls ringing in queue. Other calls should not be affected assuming the message links between the planes is healthy.