What is the maximum number of participants (tenants) that can be integrated into a building complex? DoorBird's D21DK and D21DVK systems can integrate / manage installations with up to 200 participants / tenants and up to 200 RFID tags. Published: 01/06/2021 13:31 How can DoorBird be used in a multi-party building (superstructure) or apartment building? When is a connection via the local network established? (LAN-only mode)