# An Overview of Distributed Firewalls and Controllers Intended for Mobile Cloud Computing
## 4 Challenges and Future Trends  
### Research Challenges  
Several key challenges concerning the research topic have been identified. Some of these challenges are outlined below:  
1. Integration of SDN, NFV, and CASB into a Unified System: One of the most significant challenges in integrating SDN, NFV, and CASB is ensuring seamless interoperability. These technologies often rely on different protocols, standards, and configurations, making it difficult to achieve smooth interaction. Standardising communication protocols and developing interoperable frameworks are critical to overcoming this challenge. Variations in the protocols used by different SDN controllers and NFV orchestrators can create compatibility issues. Ensuring these protocols can work together without conflict is essential for the unified system's effectiveness [63; 90; 91; 92]. \begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline \multirow{2}{*}{**Security**} & \multicolumn{3}{c}{**Performance**} \\ \cline{2-4}  & **Low Latency** & **High Throughput** & **Scalability** \\ \hline SDN offers centralised control for effective network policy management, traffic monitoring, and access control [20; 87]. & SDN’s decoupling enables efficient traffic management and reduced latency [20; 86]. & SDN’s separation simplifies network management and facilitated network evolution for improved throughput [20; 86]. & SDN’s centralised control enables efficient management and scalable distribution, and dynamic allocation of resources [20; 80; 89]. \\ The logical centralisation of security functions provides a comprehensive strategy, enhancing robustness and addressing security concerns comprehensively [68; 88]. & Centralised control optimises traffic routing, dynamically managing resources for reduced latency in MCC [20; 86]. & Networking flexibility allows efficient resource allocation and traffic flow optimisation, leading to improved throughput in MCC [20; 86]. & SDN simplifies network management, ensuring allocation and traffic flow optimisation, leading to improved throughput in MCC [20; 88]. \\ SDN’s separation of concerns simplifies network management, facilitating the implementation of distributed firewall and controller mechanisms for enhanced security [20; 88]. & & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Enhancing security and performance in MCC through SDN. Performance Optimisation in Distributed Environments: Maintaining low latency and high throughput across distributed firewalls, SDN, NFV, and CASB is a significant challenge. Each component must be optimised to work together efficiently without compromising performance. This requires advanced resource management strategies and real-time monitoring to adjust the system's configuration dynamically. Efficiently allocating and managing resources across distributed systems is complex. Ensuring that tasks are appropriately distributed to avoid bottlenecks while maintaining optimal performance is crucial [63; 66]. 3. Security Coordination and Compliance: Coordinating security measures across SDN, NFV, CASB, and distributed firewalls presents a complex challenge. Adhering to industry standards and regulations is essential, demanding strong security measures and confidentiality. Integrating these technologies calls for careful planning and coordination to build a solid security framework that protects data and network resources effectively. Additionally, implementing strict security protocols and encryption standards is critical for safeguarding sensitive information from potential breaches and unauthorised access. By adhering to industry best practices and regulatory guidelines, organisations can establish a comprehensive security strategy that mitigates risks and upholds the integrity of their network infrastructure and data assets [93; 94; 95; 96]. 4. Dynamic and Scalable Framework Design: Designing a framework that can scale dynamically in response to changing demands is essential.