Cisco, however, has adopted the term programmable networking to desribe its own vision for the future of networking -- a future that goes beyond separating the control and forwarding planes to actually permitting programming up and down the network stack. To that end, Cisco says it will address demand for programmable networks in three ways. First, it will offer software-defined networking and OpenFlow for some users. Second, Cisco will support virtual network overlays like LISP and VXLAN , to bridge the physical and virtual worlds. Third, Cisco will introduce a software development kit ( SDK ) that makes all of its routers and switches programmable through a universal API .