Point of interface
In Telecommunications a Point of Interface (POI) is used to show the physical interface between two different carriers, such as a local exchange carrier (LEC) and a wireless carrier or an LEC and an IntereXchange Carrier (IXC). This demarcation point often defines responsibility as well serving as a point for testing. In many cases, a POI exists as a point of demarcation ("DEMARC") within an LEC building, and is established under "Co-Location" agreements. A long distance, wireless, or competitive local carrier 'rents' space at the local telephone (usually tandem switch) location.
This space is physically a 'cage' in which a device for interconnecting telecom services is installed. This 'device' was originally a wire frame with one side being accessed by the LEC, and the other side accessed by the "other" carrier. In recent years, 'electronic frames' such as a digital cross-connect systems have been used as POI devices. Local exchange services are ordered from the local telephone carrier who delivers the service to 'their side' of the POI. The 'other' carrier then arranges to bring its own facilities (fiber, or other type of transport) into the POI and transport the service to its own network facilities.This point of interconnection are used in IT industries also.