[[file:Network interface device ameritech.jpg|thumb|upright|Two simple NIDs, carrying six lines each, on the outside of a building]]
[[file:apl germany.jpeg|thumb|upright|A German copper phone line termination box called ''[[:de:Abschlusspunkt Linientechnik|Abschlusspunkt LinienTechnik]]'' (APL, "[[Demarcation point]]")]]
In [[telecommunication]]s, a '''network interface device''' ('''NID'''; also known by several other names) is a device that serves as the [[demarcation point]] between the carrier's [[local loop]] and the customer's [[on-premises wiring|premises wiring]]. Outdoor telephone NIDs also provide the subscriber with access to the station wiring and serve as a convenient test point for verification of loop integrity and of the subscriber’s inside wiring.
