Incorporating nLight Silicon advancements, the Cisco line card offers aggregation and transport of high-density packet and OTN client interfaces over a DWDM infrastructure. The NCS 4000 2 x 100G DWDM line card can transport two 100 Gigabit Ethernet or OTU-4 signals over a 50 GHz spaced, 50 GHz stabilized, ITU-compliant wavelength with more than 4500 km of unregenerated reach. The card also features two pluggable client interfaces that can be used to provide transponder functionality, mapping each client signal to a single DWDM line interface.