SDN Controller Design for Dynamic Chaining of Virtual Network Functions

Network Function Virtualization (NFV) is gaining a lot of interest as a flexible and cost-effective solution for replacing hardware-based, vendor-dependent middle boxes with software appliances running on general purpose hardware in the cloud. This approach provides an unprecedented degree of flexibility with respect to conventional traffic processing based on middle-boxes. In this manuscript a methodology is investigated for the design of general traffic steering policies to implement different service chains through virtual network functions interconnected by a Software Defined Networking (SDN) infrastructure. A proof-of-concept implementation on the Open Stack platform is then presented, to provide a practical example of the feasibility and degree of complexity of the proposed approach.