VoIP Door Box
Door boxes are a phone that ring a group of business extensions by pressing it’s “call” button. The answering party can converse and also open a door latch. Door boxes are mounted on the door handle side of a door’s frame. They are also used in public parking access/security and elevator applications.
VoIP door boxes replace older analog door boxes that require expensive plain old telephone service lines. Phone people affectionately called these analog lines “POTS” lines.