The NT1 ACE3 combines the functionality of three NT1s in a single device. Connection to the ISDN network is accomplished via three U-interfaces, and connection to the subscribers' terminal equipment utilizing three S/T-interfaces. The U- and S/T-interfaces on the NT1 ACE3 conform to ANSI and CCITT standards and perform all Layer 1 functions. The NT1 ACE3 is designed with aesthetics as well as functionality in mind. The unit is enclosed in an attractive, durable plastic housing appropriate for desktop or wallmount use. The NT1 ACE3 is powered by the external power supply provided with the unit. The unit monitors the S/T-interface for over-current fault conditions. If such a condition occurs, the unit automatically limits the amount of delivered current until the fault condition is removed. The NT1 ACE3 provides 100ohm bus termination and is protected from lightning and harmful line transients on the network interfaces. Six LED status indicators on the NT1 ACE3 aid in fault isolation. Indicators display the status for Power, Network Ready, Network and Customer Errors, and Network Test. Technical Specifications: Three 2B1Q basic rate U to S/T interfaces in a single enclosure Compatible with 2B+D basic rate service Conforms to ANSI T1.601-1992 and ANSI T1.605-1991 specifications Supports multiple switch vendors; LUCENT 5ESS, NT1 DMS-100, Siemens EWSD, NEC, and National ISDN-1 Responds to Quiet Mode and Insertion Loss Test Provides automatic over-current protection for S/T power Provides U-interface lightning protection includes wall-mount power supply