To maximize the utilization of already installed security
middle-boxes, we transparently redirect network flows to
desirable security middle-boxes when needed. For example,
if a security policy specifies that a network flow should
be investigated by a security service, our NSV technology
delivers or redirects the flow to the defined security middleboxes
(regardless of its actual physical location) automatically
and transparently. Beside this kind of flow controlling, we
provide a way of enabling security response function on
each network device. Some recent technologies suggest a method to control network flows dynamically at a network device, e.g., Software-Defined Networking (SDN) [24]. With
the help of this technology, we can realize some basic security response functions at a network device. For example, we can implement a dynamic access control method at a network device by forwarding or dropping network packets. Extending this technology, we can operate necessary security response functions on a network device when they are required