# A Multi-Parameter Comprehensive Optimized Algorithm for MPTCP Networks
## 5 Result Analysis
### SRL to HU
Since buffer resources are more precious, we can reduce the waste of buffer resources by sacrificing a little throughput without affecting network performance. Therefore, the final output of the MPCOA algorithm is OBS = 12.36 MiB, OPM = PCDC, OCC = Hybla, and OTP = 74.65 Mbit/s. Figure 5 shows the relationship between buffer size and throughput, and illustrates how Equation (13) fits the data. As shown in Figure 5, PCDC with Hybla can achieve the highest throughput when the buffer size is around 18 MiB. Note that an overly large buffer--while being sufficiently big to cover a full bandwidth-RTT product--leads to \"buffer bloat\" [36; 37]: when reaching the network capacity, queues in routers start filling up, increasing the RTT, and therefore leading to a slower reaction time on packet loss. This causes a reduced performance, i.e., for buffer sizes that are too high, the throughput decreases again. Therefore, it is not that the larger the buffer size, the better the throughput performance. It is necessary to obtain the buffer size by the MPCOA algorithm. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Scenario**} & \multicolumn{4}{c}{**Relationship among Different Congestion Control (CC), Path**} \\  & \multicolumn{4}{c}{**Management (PM), Throughput and Buffer Size Obtained from the**} \\  & \multicolumn{4}{c}{**Prediction Models**} \\ \cline{2-6}  & **CC** & \multicolumn{2}{c}{**PM**} & **R and P** & **Calculation Results** \\ \hline \multirow{6}{*}{SRL-HU} & Cubic & \(tp=3.49+4.85 bs-0.15 bs^{2}\) & \(tp=6.31+5.45 bs-0.17 bs^{2}\) & \\  & OLIA & \(tp=7.01+5.26 bs-0.15 bs^{2}\) & \(tp=2.41+6.51 bs-0.17 bs^{2}\) & \\  & Hybla & \(tp=5.91+5.00 bs-0.15 bs^{2}\) & \(tp=24.49+6.16 bs-0.17 bs^{2}\) & \\  & Reno & \(tp=4.47+4.59 bs-0.15 bs^{2}\) & \(tp=3.49+5.30 bs-0.17 bs^{2}\) & \(p\)-value \(<0.00001\) & \(bs=18.12\) \\  & Scalable & \(tp=3.49+4.85 bs-0.15 bs^{2}\) & \(tp=1.99+5.64 bs-0.17 bs^{2}\) & \\  & Vegas & \(tp=4.67+4.63 bs-0.15 bs^{2}\) & \(tp=0.47+5.38 bs-0.17 bs^{2}\) & \\ \hline \multirow{6}{*}{UNIS-HiN} & Cubic & \(tp=171.62+11.08 bs-0.29 bs^{2}\) & \(tp=200.82+9.63 bs-0.27 bs^{2}\) & \\  & OLIA & \(tp=102.04+13.16 bs-0.29 bs^{2}\) & \(tp=118.6+12.25 bs-0.27 bs^{2}\) & \\  & Hybla & \(tp=109+13.48 bs-0.29 bs^{2}\) & \(tp=159.5+11.42 bs-0.27 bs^{2}\) & \\  & Reno & \(tp=111.74+13.54 bs-0.29 bs^{2}\) & \(tp=138.3+12.17 bs-0.27 bs^{2}\) & \(p\)-value \(<0.00001\) & \(bs=17.83\) \\  & Scalable & \(tp=130.48+12.95 bs-0.29 bs^{2}\) & \(tp=178.56+10.74 bs-0.27 bs^{2}\) & \\  & Vegas & \(tp=55.28+9.85 bs-0.29 bs^{2}\) & \(tp=66.8+7.77 bs-0.27 bs^{2}\) & \\ \hline \multirow{6}{*}{UIT-HAW} & Cubic & \(tp=0.763+0.002 bs\) & \(tp=0.764+0.002 bs\) & \\  & OLIA & \(tp=0.675+0.004 bs\) & \(tp=0.68+0.003 bs\) & \\  & Hybla & \(tp=0.795+0.002 bs\) & \(tp=0.796+0.002 bs\) & R-square \(=0.95\) & \(tp_{\text{max}}=0.87\) \\  & Reno & \(tp=0.753+0.002 bs\) & \(tp=0.754+0.002 bs\) & \(p\)-value \(<0.00001\) & \(bs=30\) \\  & Scalable & \(tp=0.807+0.002 bs\) & \(tp=0.808+0.002 bs\) & & \\  & Vegas & \(tp=0.743+0.002 bs\) & \(tp=0.744+0.002 bs\) & & \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Maximum throughput calculation with different PM and CC for SRL to HU, UNIS to HiN, and UiT to HAW. Figure 6 presents the throughput test results on the NorNet Core testbed for both path managers and all CC algorithms without considering the MPCOA algorithm, where the buffer size is set to be 30 MiB. In addition to the average shown by the main bars, the thin error bars present the range from absolute minimum to maximum, and the thick error bars show the range from 10% quantile to 90% quantile. As can be seen, the performance of PCDC with different CC is better than that of FullMesh with different CC. For Cubic, 26.7 Mbit/s of FullMesh vs. 32.6 Mbit/s of PCDC; For Reno, 30.8 Mbit/s vs. 33.8 Mbit/s; For Scalable, 27.5 Mbit/s vs. 34.9 Mbit/s; For Vegas, 29.2 Mbit/s vs. 31.2 Mbit/s; For OLIA, 43.0 Mbit/s vs. 50.2 Mbit/s.