Most manufacturers who adhere to SDN, often claim to have been doing it for a long time, however, this is often not strictly true- customers need a more fundamental change. They need to become less dependent on specific products and need to separate physical devices and their functionality. The network functions are transferred to the control layer - the controller function of customer equipment is limited to the throughput and connectivity. Such devices come under the common term "White switch", using software known as OpenFlow which is installed on the switch. It is obvious that such SDN solutions uniquely eliminate dependence on hardware products and significantly accelerate the selection and deployment of new network elements.
Reducing operating costs of the data network is not everything SDN offers. The network is accessible through an open defined interface which sits above the control layer. An area, which up till now has been difficult to reach, owing to the fact that the network elements was managed by NMS from individual vendors, can now, thanks, to SDN, be managed by a single controller. SDN has opened the door to applications that were previously implausible or economically unjustifiable. At the same time there are new opportunities utilising applications using SDN..