The Cisco ONS 15454 12-port DS-3 Transmultiplexer (DS3XM-12) card provides 12 Telcordia-compliant, GR-499-CORE DS-3 C-Bit or M2/3 framed interfaces operating at 44.736 Mbps.The DS3XM-12 card demultiplexes a channelized DS-3 into 28 DS-1s, maps each DS-1 to a VT1.5, then multiplexes the 28 VT1.5s into an VT-mapped STS-1 before hand-off to the Cisco ONS 15454’s cross-connect card. The integration of transmultiplexing capabilities into the Cisco ONS 15454 platform reduces the need for outboard M13 multiplexers or wideband digital cross-connect (DSX) systems to access and groom DS-1 signals from channelized DS-3 interfaces. The DS3XM-12 card offers grooming flexibility by supporting two ways to receive the DS-3 signal, ported or portless. Ported terminations refer to DS-3 interfaces that are received through 75 ohm coaxial cables from the shelf assembly’s electrical interface adapter (EIA) panels. Portless termination is a channelized DS-3 signal received over a STS-1 circuit from a SONET optical line (OC-n). The portless capability eliminates the need for intra-shelf cabling to groom a channelized DS-3 signal received via a SPE over an optical interface.