## 5 Future Work  
While this work primarily investigates the efficacy of our framework from the perspective of the Modbus protocol and its evaluation against a specific IED, the insights gained from the framework's end-to-end evaluation process nonetheless offer valuable implications for analyzing other session-based protocols within OT systems. Our results demonstrate the ability to detect vulnerabilities and other areas of concern--both within the protocol and its implementation.  
The application of formal models to identify critical transition states in Modbus demonstrates the potential for this approach to also be applied to a broader range of OT communication standards. Additionally, expanding the use of formal methods to explore the behavior of additional OT protocols could, in turn, help enhance the robustness and scalability of this framework, facilitating its wider adoption across various industrial applications. However, mapping from protocol specifications to formal models can be complex and time-consuming; thus, integrating artificial intelligence techniques could streamline this process. Machine learning algorithms, for example, could assist in identifying patterns in protocol behavior and automatically generating or refining formal models, making the framework more accessible and efficient for broader protocol support.  
In terms of simulation capabilities, one limitation of the current framework is that the OMNeT++ real-time simulator can at times struggle to accurately measure the time between packets in high-fidelity network environments. To address this, additional software tools were integrated during the network emulation stage to collect packet response timings, but improving OMNeT++'s native capabilities to handle such metrics would increase the precision and realism of the simulation. Furthermore, the current framework is only compatible with Linux platforms due to reliance on specific system-level features such as namespace creation that are not supported on Windows systems. Expanding compatibility to include other operating systems would enhance the framework's accessibility and facilitate broader deployment.  
Looking forward, supporting additional IoT protocols such as MQTT and Thread presents an exciting opportunity for future work. These protocols are widely used in modern IoT ecosystems and are critical to the operation of numerous smart devices and sensor networks. Integrating them into the framework would extend its applicability and improve its utility in simulating diverse and heterogeneous IoT environments. Furthermore, it would be valuable to explore the use of the framework in the context of emerging IIoT  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline Packets per Second & 5 & 10 & 20 & 30 & 40 & 50 & 60 & 70 & 80 \\ \hline Invalid Responses & 0 & 32 & 30 & 30 & 24 & 49 & 48 & 49 & 81 \\ \hline \end{tabular}
\end{table}
Table 1: Modbus invalid packet responses vs. attack traffic.  
protocols and technologies that require high scalability, low-latency communication, and robust security features. As the number and complexity of interconnected devices continue to grow, the ability to simulate and test such systems in a controlled environment will become increasingly important to ensure their reliability, security, and performance.  
Additionally, future efforts will focus on improving the integration of formal methods with real-time emulation, potentially combining hybrid approaches that leverage both formal verification and empirical testing to create a more comprehensive evaluation framework. This could involve integrating additional testing tools, such as fuzzing techniques or security vulnerability scanners, to complement the existing simulation and emulation capabilities. Finally, the development of a more user-friendly interface and automated reporting tools for this framework could further facilitate its adoption by industrial practitioners, enabling more streamlined evaluation and deployment of OT and IoT systems.