## 1 Introduction  
The service provision landscape has undergone a paradigm shift in recent years, driven by technological advancements and evolving user demands. Legacy networks, designed for a simpler era, are ill-equipped to address the emerging networking challenges associated with this transformation. The ubiquitous adoption of cloud computing, server virtualization, BYOD (Bring Your Own Device) environments, and the exponential growth of big data and Artificial Intelligence (AI) exemplify the new paradigms necessitating advanced network capabilities [1]. Implementing any change in conventional networks, such as adding, relocating, or removing a network device, necessitates an overhaul of the entire network configuration. Networks comprise multiple devices (switches, routers, firewalls, load balancers, etc. ), often from diverse vendors, resulting in intricate configurations that demand extensive time for implementation. The evolving needs of businesses demand enhanced networking capabilities, such as increased bandwidth, Quality of Service (QoS) control, and the convergence of voice, data, and video traffic. Legacy networks lack the dynamic agility necessary to effectively manage these demands [2]. Furthermore, scalability is a major hurdle for legacy networks. Networks typically expand to accommodate new users and their data demands, but this growth often outpaces the capacity of legacy architectures. This results in a network that is increasingly overloaded and unreliable. The need for a new abstraction layer is evident, one that enables the seamless addition of new devices while minimizing the burden on network administrators. Another significant challenge is the inability to establish consistent policies across the network. Maintaining security or QoS policies within legacy networks is an arduous task. Every network alteration requires the manual configuration of numerous devices, making it prone to errors and inconsistencies. In BYOD environments, where employees use personal mobile devices, policy enforcement becomes even more challenging, increasing the vulnerability of the corporate network to security breaches. The surge in mobile devices and users, combined with the intricacy of traditional networking, has created a perfect storm that hinders the consistent application of policy compliance mechanisms. Therefore, a fundamental shift in network architecture is necessary to overcome the limitations of legacy infrastructure. There is a need for a more adaptable, scalable, and secure network architecture that can seamlessly integrate with the evolving landscape of service provision [3]. Thus, Software-Defined Networking (SDN) [4] and Network Functions Virtualization (NFV) [5] architectures bring numerous benefits to this new computing paradigm. Their integration under a single framework, termed Software-Defined NFV (SDNFV) [6], is an active area of research and industry focus. This unified framework capitalizes on the control inherited from SDN and the flexibility gained from NFV's virtualized functions, allowing significant improvements in security issue detection and mitigation through SDNFV. Also, they are essential tools for managing security in this paradigm [7] because they are usually complementary technologies. In general, SDNFV-based networks combine SDN's network management with NFV's virtualization of network node functions, as well as the simplification of resource and service utilization within the network. Due to the integration of diverse technologies and protocols in network orchestration, security assumes a pivotal role in enhancing communication security through the deployment of innovative mechanisms. Traditional security measures like Intrusion Detection Systems (IDS), firewalls, and others are traditionally stationed at the network periphery to find of external threats. However, the advent of new network architectures necessitates novel security mechanisms to fortify services and networks, such as those employed in traditional deployments [8].