Dear Nikhil :
do you mean :
FPGA + ASIC(CISCO IP) = Cisco nPower™ X1 ?

Why Cisco doesn’t use xilinx FPGA or Achronix or Tabula (3D) or Tri-gate FPGA ?
I think in SDN Networks, using 3D FPGAs Better than ASIC, FPGA is very flexible.
Even cisco could using optical ASIC (Reflexphotonics) or FPGA (Altera optical FPGA), with optical Interlaken and optical backplanes (pci-ex or optical rapid i/o).

FPGAs add comms cores amid ASIC debate :
(EETIMES)

Xilinx showcases 400G apps for optical and wired OTN Markets at OFC 2013 :
(EETIMES)