# On Cross-Layer Interactions for Congestion Control in the Internet
## 5 Performance Evaluation
### Data Center, Mixed TCPs
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & \multicolumn{3}{c}{**DT**} & \multicolumn{3}{c}{**PIE**} & \multicolumn{3}{c}{**CoDel**} \\ \hline \multicolumn{2}{c}{} & \multicolumn{1}{c}{**AvgThr (SD)**} & \multicolumn{1}{c}{**BD [\%]**} & \multicolumn{1}{c}{**JI**} & \multicolumn{1}{c}{**AvgThr (SD)**} & \multicolumn{1}{c}{**BD [\%]**} & \multicolumn{1}{c}{**JI**} & \multicolumn{1}{c}{**AvgThr (SD)**} & \multicolumn{1}{c}{**BD [\%]**} & \multicolumn{1}{c}{**JI**} \\ \hline \multirow{3}{*}{UC} & NReno & 188 (37) & 61 & 0.97 & 128 (6) & 42 & 1.00 & 117 (9) & 38 & 1.00 \\ \cline{2-11}  & Cubic & 86 (5) & 28 & 1.00 & 109 (8) & 35 & 1.00 & 112 (5) & 36 & 1.00 \\ \cline{2-11}  & C-TCP & 34 (15) & 11 & 0.89 & 71 (1) & 23 & 1.00 & 78 (6) & 25 & 1.00 \\ \cline{2-11}  & All & 103 (71) & 100 & 0.70 & 103 (26) & 100 & 0.95 & 103 (19) & 100 & 0.97 \\ \hline \multirow{3}{*}{MC} & NReno & 21.44 (7,52) & 69 & 0.89 & 9.85 (0.48) & 31 & 1.00 & 9.84 (0.50) & 31 & 1.00 \\ \cline{2-11}  & Cubic & 4.55 (1.02) & 15 & 0.95 & 10.97 (0.51) & 35 & 1.00 & 10.98 (0.39) & 35 & 1.00 \\ \cline{2-11}  & C-TCP & 5.30 (1.95) & 17 & 0.88 & 10.47 (0.36) & 33 & 1.00 & 10.46 (0.37) & 33 & 1.00 \\ \cline{2-11}  & All & 10.43 (9) & 100 & 0.57 & 10.43 (0.6) & 100 & 1.00 & 10.43 (0.6) & 100 & 1.00 \\ \hline \multirow{3}{*}{HC} & NReno & 0 (0) & \(>\)1 & 0.15 & 0.91 (0.09) & 29 & 0.99 & 0.95 (0.08) & 30 & 0.99 \\ \cline{2-11}  & Cubic & 3.17 (2.24) & \(\sim\)99 & 0.67 & 1.21 (0.11) & 38 & 0.99 & 1.16 (0.10) & 37 & 0.99 \\ \cline{1-1} \cline{2-11}  & C-TCP & 0 (0) & \(>\)1 & 0.01 & 1.06 (0.09) & 33 & 0.99 & 1.06 (0.07) & 33 & 1.00 \\ \cline{1-1} \cline{2-11}  & All & 1.06 (2) & 100 & 0.22 & 1.06 (0.15) & 100 & 0.98 & 1.06 (0.12) & 100 & 0.99 \\ \hline \hline \end{tabular}
\end{table} 
Table 10: The summary results in the data center scenario with mixed TCPs, UC—uncongested, MC—mildly congested, HC—heavily congested network. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & \multicolumn{2}{c}{**DT**} & \multicolumn{2}{c}{**PIE**} & \multicolumn{2}{c}{**CoDel**} \\ \hline \multicolumn{2}{c}{} & QS (SD) & DR & QS (SD) & DR & QS (SD) & DR \\ \hline UC & 825 (57) & 0.07 & 168 (34) & 0.08 & 168 (11) & 0.08 \\ \hline MC & 881 (20) & 0.56 & 167 (27) & 1.67 & 209 (22) & 1.49 \\ \hline HC & 899 (1) & 0.80 & 169 (52) & 6.86 & 723 (217) & 6.12 \\ \hline \hline \end{tabular}
\end{table} 
Table 11: Mean queue length (QS) and standard deviation (SD) of queue length [pkts] and packet drop ratio (DR) [%] in the Data center scenario with mixed TCPs, UC—uncongested, MC—mildly congested, HC—heavily congested network. We summarize our findings are follows:  
* Applying PIE or CoDel significantly improves the inter- and intra-fairness among competing flows using different TCP versions. * CoDel maintains a short and stable queue only if the network is not overloaded. The average queue size provided by CoDel depends on the network load. * PIE provides satisfactory and comparable results regarding fairness, drop ratio, and queue stability in all network load scenarios.