DS3/2DS3+8xT1 IMA I/O card provides, when used with the OC-3c/OC-3c NI-2 card, one network OC-3c WAN trunk interface and one OC-3c subtend interface through connectors located on the NI-2 card faceplate. It also provides five rows of six wire-wrap pins located on the right side of the DS3/2DS3+8xT1 IMA I/O card that support central office alarm relay interfaces (visual and audible) between the NI-2 card and the subscriber and building integrated timing source (BITS) clock input circuits. The card supports up to 12 additional subtended node chassis, configured for DS3, T1, or T1 IMA operation.The DS3/2DS3+8xT1 IMA I/O card provides three sets of two vertically paired DS3 75-ohm Bayonet-Neill-Concelman (BNC) coaxial cable connectors that are located on the left side of the DS3/2DS3+8xT1 IMA I/O card. Each set of port connectors has both a transmit (TX) connector and a receive (RX) connector.