# Novel Multi-Level Dynamic Traffic Load-Balancing Protocol for Data Center
## 5 Results and Discussion  
The proposed algorithm was implemented in a Network Simulator 3 (NS3) environment. The simulation environment was configured using the selected parameters. The simulation parameters are listed in Table 5. We tested MDTLB under a symmetric 4 \(\times\) 4 leaf-spine topology, as shown in \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Events** & **1** & **2** & **3** & **4** & **5** & **6** & **7** & **8** & **9** \\ \hline
**Flow** & A & B & C & D & E & F & G & H & I \\
**P1 type** & Grey & Bad & Good & Bad & Very Bad & Very Bad & Very Good & Good & Good \\
**P2 type** & Grey & Gray & Bad & Bad & Good & Bad & Good & Good & Bad \\
**chosen path** & P1 & P2 & P1 & P1 & P2 & P2 & P1 & P2 & P1 \\
**Dynamic thresholds** & No change & +10\% & No change & +10\% & No change & +10\% & \(-10\%\) & \(-10\%\) & No change \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Example summary. Figure 8: The example of the multi-level dynamic traffic load-balancing (MDTLB) method. Figure 9, with 64 hosts connected by 10 Gbps links. We simulate a 2:1 oversubscription at the leaf level similar to the typical data center deployments. \begin{table}
\begin{tabular}{c c} \hline \hline
**Values** & **Parameters** \\ \hline runMode & MDTLB, TLB (Hermes), Conga, Presto, DRB, ECMP, Clove, DRILL, \\  & LeftFlow \\ transportProt & Tcp \\ enableLargeDupAck & False \\ enableLargeSynRetries & False \\ enableFastReConnection & False \\ enableLargeDataRetries & False \\ For each leaf serverCount & 8 \\ spineCount & 4 \\ leafCount & 4 \\ linkCount & 1 \\ spineLeafCapacity & 10 \\ leafServerCapacity & 10 Gbps \\ linkLatency & 10 us \\ cdfFileName & data mining: VL2\_CDF, web search: DCTCP\_CDF, general flows: \\  & (VL2\_DF + DCTCP\_CDF)/2 \\ load & [0.3, 0.5, 0.7, 0.9] \\ MDTLBMinRTTS & 40 us \\ MDTLBHighRTTS & 180 us \\ Initial MDTLBMinRTTD & 40 us \\ Initial MDTLBHighRTTD & 180 us \\ MDTLBBetterPathRTT & 1 us \\ MDTLBT1 & 100 us \\ MDTLBECNPortionLow & 0.1 \\ MDTLBProbingEnable & True \\ MDTLBProbingInterval & 50 us \\ MDTLBSmooth & True \\ MDTLBRerouting & True \\ MDTLBS & 64,000 byte \\ MDTLBReverseACK & True \\ quantifyRTTBase & 10 \\ MDTLBFlowletTimeout & 5 ms \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Simulation Parameters. Figure 9: Leaf-Spine topology. We evaluate and measure the performance of the proposed MDTLB by two main metrics: the (normalized) flow completion time (FCT) and the throughput. To do so, general flow, data mining, and the web search workload were used. The observation of the FCT of general flows, with three types of flows, are also shown separately for short flows, long flows, and both short and long flows in Figure 10. Similarly, in Figures 11 and 12, the observation was made for the flow completion time (FCT) of web search and data-mining, respectively. In all of the figures of FCT, the results were normalized to MDTLB protocol in order to have better visualization for comparing results. Figure 10: Flow completion time of various loads for the general flows in the symmetric topology with three types of flows: **(a)** short flows FCT; **(b)** long flows FCT; **(c)** and overall FCT of both short and long flows. Figure 11: Flow completion time of various loads for the web search application in the symmetric topology with three types of flows: (**a**) short flows FCT; (**b**) long flows FCT; (**c**) and overall FCT of both short and long flows. Figure 12: Flow completion time of various loads for the data-mining application in the symmetric topology with three types of flows: (**a**) short flows FCT; (**b**) long flows FCT; (**c**) and overall FCT of both short and long Flows. From the above results, the following observation can be made:  
**Under general workload**  
As we observe in Figure 10, we use the FCT of short flows, long flows, and a combination of both short and long flows with general flows to compare the MDTLB performance with other protocols. All of the FCTs were normalized to MDTLB for easy visualization.