http://www.linux.com/news/enterprise/networking/786720-10-reasons-to-use-open-source-software-defined-networking-
http://thenewstack.io/defining-software-defined-networking-part-1
http://ostatic.com/blog/red-hat-and-partners-aim-to-infuse-open-nfv-tools-in-telco-data-centers
http://www.biztechmagazine.com/article/2016/10/software-defined-networking-puts-network-managers-drivers-seat