Enterprise networks need to be reliable. That has been a given for many years. Flexibility wasn't part of the equation. But now software-defined networking (SDN) is changing the way IT and administrators are thinking about network architecture. With all the hype and promise surrounding SDN, what is the true state of this technology? To get a clearer view of SDN in 2016, Senior Editor Sara Peters spoke to Eric Hanselman, chief analyst at 451 Research, about how enterprises view the technology and where the industry is in terms of adoption and costs -- and what's next.