Each location will have an intercom system. This will also include houses. There will be a single telephone number for all of the intercom systems to reduce cost. The tenant can add the number into their contacts to let them know that the door system is being used to contact you. When your button is selected, there will be a telephone call to your telephone number. You would either answer, or let it go to voicemail. If you answer, and will want the visitor to enter, then you will select the * key which is next to the 0 on a numeric keypad. If you don’t answer, then the visitor will be forwarded to your voicemail system where they can leave a message for you at your voicemail. This means you can use your regular voicemail system for your telephone.
This will seem over-kill for a single residence house, but the alternative will be a Ring doorbell system which will not be as functional as the intercom system. As long as they are carrying their phone, they will be notified of a person at the front door. This is designed to make life easier, and more capable. And since this number to ring to can be a cellular phone, the visitor will have no idea if you are home or not.