SDN and NFV are expected to do two good things. Foster agility with faster to market, faster to provision and so on. And they should also do good things to Capex and operational expenditure savings, says Marc Cohn, Chair of Market Education Committee for the Open Network Foundation and Senior Director of Market Development at Ciena. But the real potential, he tells Martyn Warwick, is not in the nitty gritty but rather the idea of opening up the platform and separating the software and the hardware.