## 4 Results and Analysis
### Network Parameter Evaluation
#### 4.2.4 Study on Instantaneous Throughput  
The throughput for each instance when messages were sent was calculated, and the statistical summary of the instantaneous throughput in bytes per second was noted. This reveals the statistics as shown in Table 7 and Figure 21.  
The average instantaneous throughput of 226.83 bytes per second, with peaks of up to 717.65 bytes per second, represents the encryption system's performance under current conditions. The mean instantaneous throughput (226.83 bytes per second) is higher than the median (203.98 bytes per second), indicating a right-skewed distribution which suggests that while most of the network transmissions achieve throughput values around the lower  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Statistic** & **Value (bytes/s)** \\ \hline Number of Observations & 31 \\ Mean & 226.83 \\ Standard Deviation & 103.29 \\ Minimum & 114.77 \\
25 th Percentile (Q1) & 161.68 \\ Median (Q2) & 203.98 \\
75 th Percentile (Q3) & 247.82 \\ Maximum & 717.65 \\ \hline \hline \end{tabular}
\end{table}
Table 7: Statistical overview of data throughput.  
Figure 20: Correlation between transmission time (sec) represented by blue dots and bytes in payload for 31 different messages of varying sizes with varying transmission times, illustrating an upward growing trend.  
end of the range, there are a few instances where the network achieves significantly higher throughput. Although this throughput with the current method is sufficient for control plane operations, like flow rule management and policy enforcement, it is significantly below the data plane requirements in modern SDN environments, which typically require throughput ranging from 100 Mbps to 10 Gbps [65]. It highlights the necessity for exploring approaches to be deployed alongside the proposed method to enhance throughput. To properly understand how the throughput behaves as the network transmission scales up, it is important to study its behavior against the bytes of data transmitted in the instance [66]. For this, the correlation between bytes transmitted and instantaneous throughput has been studied, as shown in Figure 22.  
Figure 22 depicts a scatter plot for bytes received against instantaneous throughput. There is a correlation coefficient value of 0.86, indicating a positive linear and direct relationship with a good fit between the variables, which means that more data are being  
Figure 21: Instantaneous throughput for 31 different message instances transmitted between hosts h1 and h4 during the test of encryption policy.  
Figure 22: Correlation between the bytes transmitted and instantaneous throughput, as represented by the \(x\)-axis and by blue dots, respectively, in the designed SDN architecture during the emulation process.  
processed with increasing throughput in proportion ratio. The graph clearly shows that data are being transferred efficiently with an increasing transmission volume. In networking terms, it implies that the currently designed network infrastructure is efficient with optimal bandwidth and resources to cope with higher data rates and can efficiently scale up with high throughput as the amount of data transmission increases [67] without noticeable diminution in performance.  
In conclusion, from the observed range of throughput and trend by correlation, it can be deduced that although the system has encouraging signs with regard to efficient scaling at its current limit, enhancing throughput is required for better operation. To ensure performance as the network scales towards higher data rates and to enhance and avoid possible bottlenecks caused by throughput, optimization through hardware acceleration and parallel and distributed processing approaches need to be explored.