NT

In ISDN networks, a set of functions accomplished through the use of programmed logic variously embedded in the carrier network and the customer premises equipment (CPE). NT devices operate to interface the four-wire customer wiring to the physical two-wire UTP local loop, performing functions similar to those provided by digital service units (DSUs) and channel service units (CSUs) in non-ISDN digital networks. See also CPE, CSU, DSU, four-wire circuit, ISDN, NT1, NT2, and two-wire circuit.