## 5 Results and Discussion
We also showed that the exponential backoff mechanism, while a standard feature of TCP/IP to prevent congestion, introduces unacceptable delays in scenarios where prompt data transmission is critical, such as when OT protocols are used in safety-critical environments or scenarios. Our tests revealed that connection recovery \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Paper**} & \multicolumn{3}{c}{**Vulnerability**} & \multicolumn{3}{c}{**Mitigation**} \\  & **Identification** & **Evaluation** & **Device Security** & **External** & **Software-Defined** \\  & & **Features** & **Firewall or IDS** & **Networking** \\ \hline
[9] & ✓ & ✓ & X & X & X \\ \hline
[10] & ✓ & ✓ & X & ✓ & ✓ \\ \hline
[11] & ✓ & ✓ & ✓ & ✓ & X \\ \hline
[12] & X & ✓ & X & ✓ & X \\ \hline
[13] & X & ✓ & X & ✓ & X \\ \hline
[14] & ✓ & ✓ & X & ✓ & X \\ \hline
[25] & ✓ & ✓ & X & ✓ & X \\ \hline Our Work & ✓ & ✓ & ✓ & ✓ & ✓ \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Our paper’s contributions in relation to other related works. delays can approach or exceed 40 s, which could be catastrophic in industrial contexts requiring real-time actuation or monitoring. Specifically, excessive latency can, for example, cause improper operations of assembly lines [30] resulting in defective products, or damage to smart grid components in the event of cascade failures not being curtailed in time [31]. In contrast, DNP3's more symmetrical approach to connection management, where both the master and outstation may initiate communication, provides enhanced resilience. The specification's support for reconnection upon data availability ensures quicker recovery from network disruptions, particularly in distributed or resource-constrained environments. These protocol-level behaviors underscore the importance of selecting communication standards based not just on compatibility or performance, but also on fault tolerance and the expected operational environment. This raises an important consideration for OT system operators: the tangible benefits of upgrading legacy systems to modern, networked architectures. One key advantage is improved communication performance--not only in terms of speed, but also reduced latency, increased reliability, and lower message loss rates. These enhancements benefit not just sensors, but also actuators, PLCs, and other critical components that rely on a timely and accurate data exchange. Upgrading also enables broader protocol support, improves interoperability across devices, and helps phase out outdated or insecure technologies. While such transitions can introduce new security challenges, they also provide the foundation for greater system visibility, future-proofing, and more robust operational control. Our testbed simulations further reinforced these findings. The integration of Modbus TCP with DNP3 via a gateway offered a practical bridge between legacy and modern OT systems but also introduced new potential points of failure. In particular, gateway devices, if misconfigured or targeted by malicious traffic, may become bottlenecks or vulnerabilities in the network. However, our implementation of defense-in-depth mitigations, including a dedicated security gateway and software-defined switching, proved to be effective. Despite introducing minor additional latency (as shown in Table 1), these tools can significantly enhance the security posture of OT networks with negligible performance penalties. Importantly, these mitigations help address a broader concern observed in related works: the lack of intrinsic security in many legacy OT protocols. Unlike newer industrial communication standards, both Modbus TCP and DNP3 were not originally designed with cybersecurity threats in mind. While DNP3 has evolved to include secure authentication, the default behavior of many deployed systems still reflects legacy assumptions. Therefore, supplementary protection mechanisms, such as whitelisting and SYN-flood prevention, remain essential components in securing these networks.