These clever IP door viewers hold the access controller crafted in to the reader. They can be driven using Power in excess of Ethernet (PoE). Anything is within the door, so the wiring is a lot easier. *The IP reader-controllers are substantially diverse compared to the more mature door access https://andyxlvsm.tribunablog.com/the-fact-about-door-access-system-that-no-one-is-suggesting-49750409