# An Overview of Distributed Firewalls and Controllers Intended for Mobile Cloud Computing
## 1 Introduction
Thus, it is essential to analyse and address security issues across various network components, including mobile devices, networks, mobile applications, and their security [16]. In distributed firewalls and controllers for MCC, it is important to focus on data protection, secure task allocation, optimal service selection, and the security and privacy of personal data. Using encryption, access control, authentication, and adaptive context-aware optimisation techniques can help create an effective and secure system [17; 18; 19]. It is recommended to integrate SDN, NFV, and CASB as these advanced technologies offer more versatile and efficient security mechanisms than conventional systems [19; 20; 21]. Figure 1 represents the network of the distributed firewalls in MCC, showing the well-distributed firewalls and the client's device. The integration of SDN allows for centralised control and programmable networks [20], enhancing visibility and control over network traffic for improved security threat detection and prevention [22]. On the other hand, NFV virtualises network functions, facilitating the scalable and adaptable deployment of security functions [23] to accommodate evolving security demands in MCC environments [24]. The integration of NFV enables organisations to deploy and manage security functions more efficiently, leading to reduced costs and improved scalability [25]. Additionally, CASB provides visibility and control over cloud-based applications and data, enforcing security policies and improving data security, authentication, and accountability in mobile cloud applications [26; 27; 28]. The integration of CASB allows organisations to enforce security policies and mitigate potential threats in the mobile cloud environment [29]. The integration of SDN and NFV into MCC can potentially improve performance, scalability, and network management. [PERSON]'s research [23] explores the interplay between NFV, SDN, and cloud computing, highlighting the innovative aspects of NFV and identifying potential areas for future research. Additionally, [PERSON] et al. [30] introduce a combined SDN/NFV orchestration framework designed for the deployment of virtual backhaul networks in mobile environments, showcasing the dynamic capabilities of such integration. Furthermore, [PERSON] and [PERSON] [31] propose that combining SDN and NFV provides a practical approach to managing virtual networks on demand, effectively meeting the growing data traffic needs in smart city environments. This integration is also supported by [PERSON] [32] who stresses that SDN and NFV architectures enable the optimisation of network and cloud resources, facilitating enhanced performance and flexibility. Leveraging SDN and NFV in MCC can lead to an improved quality of service, as discussed by [PERSON] et al. [33] who demonstrate the integration of SDN/NFV virtualisation in a 5G multi-RAT scenario for smart television services. However, there is a gap in the current literature regarding the insufficient attention given to security aspects and policies within the integrated system, which can be addressed by incorporating CASB. While the current studies focus on the technical aspects of SDN, NFV, and cloud computing integration, there is a notable absence of in-depth analysis regarding the security implications and mechanisms necessary for ensuring secure data transmission and access control within the MCC environment. Introducing CASB into the integrated system could address this gap by providing security enforcement and monitoring across cloud services, applications, and data exchanges. CASB solutions offer data encryption, access control,  
Figure 1: Distributed Firewalls. threat detection, and compliance monitoring, which are essential for securing data flow within the dynamic MCC environment. Incorporating CASB into the system architecture allows for the dynamic application and enforcement of security policies in real time, ensuring data protection and compliance with regulatory requirements.