typical cycle of innovation for the network opera- tor. Economies of scale required to cover investments in hardware-based functions are strongly mitigated through software-based deployment, which more or less follows a vari- able cost model and is far more fluid. Reduced costs by sharing resources across many services and different customer bases. Ability to run multiple versions of a network function is simple since the functions are implemented in software. Virtualization enables multitenancy, which allows the use of a single platform for different applications, users, and tenants. Targeted service introduction based on geography or customer sets is possible. Services can be rapidly scaled up or down as required. Ability to deploy systems that elastically support various network functional demands and which allow directing the capacity of a common resource pool against a current mix of demands in a flexible manner. Enable a wide variety of ecosystems and encourage openness. NFV opens the virtual appli- ance market to pure software entrants, small players, and academia-thus encouraging innovation in bringing more new services and new revenue streams quickly, at a much lower risk. Enable new types of network services. NFV can readily be applied to the control and man- agement plane in addition to the data plane. This allows virtual networks to be created and managed by end users and third parties using the tools and capabilities heretofore reserved only for native network operators. Faster testing of new services. Testing and certification of complex services is a time- consuming endeavor. Often, it is difficult to test the field of use in a laboratory environ- ment. The multitenancy aspect of NFV enables the service provider to test new services and updates in a production setting without risking real customer traffic. Higher reliability; software-based systems can be made resilient more easily and inexpen- sively. Hardware-based reliability tends to be more expensive due to the need to deploy special-purpose r