New to the Samsung product...how can I setup a phone to cover to another phone if not answered (for all calls)? Can I assign multiple call coverage buttons for the same extension on the covering phone? If phone A has an active call and phone B has a CC button for phone A, can phone B answer the second incoming call for phone A? How can I accomplish this and I need to make sure that the last point of coverage is voicemail for phone A if not answered by A or B. Thank you.