As 2013 winds down and many take time to reflect on the things that mean most to them, it’s only fitting to check the pulse of progress on the software-defined networking (SDN) front as well. For all that has been said about software defined networking and network virtualization, one thing is certain: Networks are evolving to become as fluid and responsive as cloud applications need them to be, and the shifts in operational mindset that embody SDN have been translated to technologies that can be put to the test in real environments…