7). The objective of NFV is to separate the VNFs from the infrastructure including their management. As shown in Fig. 1.7, the MANO functions are divided between the MANO of the NFVI and the MANO of the VNFs. The MANO of the NFVI is an integral part of the NFV framework. One possible scenario is the management of the existing NFs that are partially virtualized by an NFV deployment. Managing the VNFs using the existing systems can be used for the deployment of NFV in the transition period as illustrated in Fig. 1.7. The removal of the hardware from the VNFs elimi- nates the requirement of managing hardware aspects. The flexibility provided by NFV can only 26 Chapter 1 be fully achieved, if the MANO implements efficient VNF life cycle management process adapted to new requirements such as fast order delivery, fast recovery, and auto-scaling. 1.1.3 Separation of Control and User Planes (Software-Defined Networks) SDN is an emerging architecture that is dynamic, manageable, cost-effective, and adaptable, making it ideal for the high bandwidth, dynamic nature of today's applications. This architec- ture decouples the network control and forwarding functions, enabling the network control to become directly programmable and the underlying infrastructure to be abstracted for applica- tions and network services. The OpenFlow protocol is a fundamental element for building SDN solutions. The OpenFlow standard, created in 2008, was recognized as the first SDN architecture that defined how the control- and data-plane elements would be separated and communicate with each other using the OpenFlow protocol. The Open Networking Foundation (ONF) 16 is the body in charge of managing OpenFlow standards, which are open- source specifications. However, there are other standards and open-source organizations with SDN resources, thus OpenFlow is not the only protocol that makes up SDN framework. SDN is a complementary approach to NFV for network management. While they both manage net- works, both rely on different methods. SDN offers a 