A little-known fact about the engineering team for Lync and Skype is that many of the people came out of the core networking division for Windows Server. While most of the world looks at Lync as a great unified communications software package, underlying its user interface and capabilities are lots and lots of networking protocols. Folks who spend any time with the deployment, configuration, or operations of Lync certainly realize this – there’s a lot going on with the “wire,” whether that’s over the air or on copper.
Networking is very much in the DNA of Lync, so when the industry started rallying around Software-Defined Networking (SDN), we were excited to participate. SDN has been defined in a bunch of ways and I encourage you to explore the topic, but generally you can think of two things. First, separating the low-level network functions into commodity hardware controlled by a software-based platform. Second, having applications inform the software controller of their requirements of the network. This concept started with cloud-scale data centers and has been moving down-market as enterprise network architects realize the power of this model.
Read more at source: http://blogs.technet.com/b/lync/archive/2013/12/17/lync-and-software-defined-networking.aspx