# Scalable OneM2M IoT Open-Source Platform Evaluated in an SDN Optical Network Controller Scenario +
## 4 Results  
As previously explained in Section 3.3, for the first experiment, we have chosen the rate \(R_{POST}\) as the performance metric, that is the number of POST messages per second that are successfully received and elaborated by the Mobius OneM2M platform. The graph of Figure 7 shows the trend of the rate for a varying number of sending nodes (\(N\)), depending on the sleeping time that has been chosen between consecutive bursts of update messages. With \(N=100\) ROADMs sending POST messages with optical parameter updates, an average value of \(R_{POST}>18\) messages has been achieved (more than 65000 messages in one hour of testing). With \(N=1000\) ROADMs, we measured a rate \(R_{POST}>5\) messages per second. When the sleeping time increases, the number of messages sent to the OneM2M decreases, and the same obviously happens to the rate \(R_{POST}\). The effect is more evident for smaller \(N\), as the sleeping times occur with a greater frequency. However, the trend in the graphs for the different sleeping times remains almost the same. Table 1 shows the 25 th percentile, the median and the 75 th percentile for the produced results. Figure 6: UML sequence schema of the interactions between the network components. The results confirm the capability of the network devices to efficiently provide parameter status updates to the controller in real-time, as the updates arrive with no significant delays. The network behaves as expected even when the number of sending nodes (and consequently the number of messages in the network) increases. Moreover, the moment of the day (work hours or nights) or the day of the week (working days or weekends) do not influence the results. The experiment also confirms the efficiency of the OneM2M in handling numerous network devices and an increasing number of update messages, obtaining satisfactory scalability performance. The rate of messages per second remains of the same order of magnitude. In the second experiment, we evaluated the configuration time \(T_{C}\) elapsed between the instant when the status of a connection is enforced at the Mobius Controller and the instant when all configuration messages are received by the subscribed ROADM agents interested in the update. Figure 8 shows the configuration time, varying the number \(M\) of nodes subscribed to configuration messages (e.g., the nodes that receive the configuration messages from the OneM2M platform) and the sleeping time that has been chosen between consecutive update messages from the \(N\) nodes of the network (e.g., all the nodes present in the network, that in background send update messages to the OneM2M platform). For example, with \(N=25\), \(M=5\), and ROADMs generating the status message every 30 s, an average value \(T_{C}\) in the order of 75 ms is achieved. With \(N=25\), \(M=10\), \(T_{C}\) is in the order of 120 ms. The configuration time \(T_{C}\) increases marginally when the sleeping time between consecutive update messages decreases, to a high update transmission rate. For example, with \(N=25\), \(M=5\), and ROADMs generating a message every 2 s, we obtained an average value \(T_{C}\) in the order of 87 ms. Considering that we achieved a \(T_{C}\) of 75 ms with a sleeping time of 30 s, the difference between the two values is minimal. The graph also confirms that the time required to enforce the configuration at the ROADM agents remains the same order of magnitude when the number of update messages in the network increases (e.g., bursts of update messages are sent more frequently as the sleeping time is \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Sleeping Time** & **25 th Percentile** & **50 th Percentile** & **75 th Percentile** \\ \hline
0s & 8.34722222 & 13.0416667 & 17.2361111 \\
0.5s & 6.719097222 & 9.31083333 & 11.7086111 \\
1s & 5.062430556 & 7.410694444 & 9.640625 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: 25 th percentile, median and 75 th percentile of results for the first experiment.