twork (VPN's) VPN are a way to provide the secure connectivity to a private network using the public network. VPN works on tunneling by creating a path through the public network to provide access to private networks. Virtual private networks either provide site to site secure connectivity or remote access to intranet. Active and Programmable Networks The concept of active and programmable networks came into picture with a requirement of flexible network for easy configuration and management. It comes with two different approaches one was open signaling and the other was active networks approach. The open signaling approach works on abstraction of logical layer from physical layer where as Active network approach supports dynamic deployment of the services. Overlay Networks Overlay networks are logical network created over a physical network. Peer to peer networks is an example of an overlay networks. Overlay networks creates new kind of network services over an existing network removes the need of changing of the underlying physical networks. Evolution of NFV The foundation of NFV started in 2012 when the telecom service providers selected ETSI as the standard body for the development of NFV specification. ETSI is now a collaboration of more than 200 companies working together to provide standard, specification and development approach towards NFV. The specification published in 2013 covers infrastructural overview, framework for architecture, management and orchestration and security. Downloaded: 4/15/2022 9:44:49 AM Nova Southeastern University IP Address: 137.52.76.29 Introduction to SDN and NFV NFV FRAMEWORK As described by the NFV ISG, Network Functions Virtualization framework has three main components: NFV Infrastructure (NFVI) "NFVI is the totality of the hardware and software components which build up the environment in which VNFs are deployed." (ETSI GS NFV INF 001 V1.1.1 (2015- 01) To support the various use cases and the applications fields already identified by the NFV ISG, a common infrastructure c