The NI-2 card is a system processor module that connects to the xTU-C line cards through point-to-point serial data buses on the backplane. Contains the ATM switch fabric. Supports subtending of as many as 12 subtended node chassis. Provides visual and audible operating status alerts; CO facility alarm relay contact interfaces and an alarm cut-off (ACO) button; Cisco IOS-based ATM quality of service (QoS). The NI-2 card is manageable through Cisco IOS software or Cisco Digital Subscriber Line Manager (CDM).