rtant revenue-generating services. Integration: Seamless integration of multiple virtual appliances into existing industrial- grade servers and hypervisors is a major challenge for NFV schemes. Network operators need to be able to combine servers, hypervisors, and virtual appliances from different vendors without incurring significant integration costs. The ecosystem offers integration services and maintenance and third-party application support. It must be possible to resolve integration issues between several suppliers. The ecosystem will require mechanisms to validate new NFV products. Tools must be identified and/or created to address these issues. 1.1.2.1 Architectural Aspects The NFV initiative began when network operators attempted to accelerate deployment of new network services in order to advance their revenue and growth plans. They found that customized hardware-based equipment limited their ability to achieve these goals. They studied standard IT virtualization technologies and found NFV helped accelerate service innovation and provisioning in that space [48]. 5G Network Architecture Management and orchestration (MANO) Vi-Vnfm Or-Vi Virtualized infrastructure NFV infrastructure (NFVI) manager (VIM) Nf-Vi Software-defined networking (SDN) controller Figure 1.3 High-level concept of a virtualized network. Fig. 1.3 illustrates the conceptual structure of a virtualized network and its main compo- nents. Following conversion of physical NFs to software, that is, virtual network functions (VNFs), the software applications need a platform to run. The NFV infrastructure (NFVI) consists of physical and virtual compute, storage, and networking resources that VNFs need to run. The NFVI layer primarily interacts with two other NFV framework components: VNFs and the virtual infrastructure manager (VIM). As we mentioned earlier, the VNF soft- ware runs on NFVI. The VIM, on the other hand, is responsible for provisioning and man- aging the virtual infrastructure. As shown in Fig. 1.4, the VNF to NFVI interface (Vn-N