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List of Figures 

2-1 The Modeling State-Space Problem __________________________________________ 15 

2-2 A Method to Reduce the Scale of Computational Demands _______________________ 16 

2-3 An Example Applying Scale Reduction to MesoNet Simulations __________________ 17 

2-4 Reducing the Space of Model Responses using Correlation and/or Principal 

Components Analysis ______________________________________________________ 21 

3-1 Topology used for simulation experiments discussed in this study _________________ 38 

4-1 Encoding Template for a 211-5 Orthogonal Fractional Factorial Experiment Design __ 75 

4-2 Enlargement of Sample Scatter Plot of Response y7 vs. y2 _______________________ 80 

4-3 Sample (and Partial) Table of Correlations among Response Pairs ________________ 80 

4-4 Sample Histogram of Correlation Magnitudes among Response Pairs _____________ 81 

4-5 Sample 6-x-6 Subset from a Combined Matrix of Scatter Plots and Correlation Values 82 

4-6 Index-Index Plot Identifying Response Pairs with Correlation Magnitude above 0.65 _ 83 

4-7 Enlargement of a Sample Weight Vector for First Principal Component ___________ 84 

4-8 Enlargement of a Sample Histogram for First Principal Component _______________ 85 

4-9 Sample Main Effects Plot for Response y11, average congestion window size ________ 87 

4-10 Sample Y-Y-X plot for Responses y7 and y22 __________________________________ 88 

4-11 Example Illustrating the Technique used to Summarize System Responses _________ 102 

4-12 Sample Data Summarization: 22 Responses for each of 64 Simulation Runs ________ 103 

4-13 Combined Matrix of Scatter Plots and Correlation Values for 22 Responses ________ 103 

4-14 Frequency Distribution of the Absolute Value of Correlations for All Pairs of 

Responses ________________________________________________________________ 104

4-15 Clustered Index-Index Plot for Correlation Pairs where |Correlation (Yi, Yj)| > 0.65 __ 105 

4-16 Histograms for 22 Principal Components _____________________________________ 109 

4-17 Weight Vectors for the First Four Principal Components ________________________ 109 

4-18 Main-Effects Plot for Response y1 (Average Number of Active Flows) _____________ 112 

4-19 Main-Effects Plot for Response y10 (Average Retransmission Rate) _______________ 114

4-20 Main-Effects Plot for Response y22 (Average Instantaneous Throughput for NN

Flows) ___________________________________________________________________ 115 

4-21 Main-Effects Plot for Response y15 (Average Smoothed Round-Trip Time) _________ 116 

4-22 Main-Effects Plot for Response y4 (Average Packets Output per Measurement 

Interval) _________________________________________________________________ 117 

4-23 Main-Effects Plot for Response y6 (Flows Completed per Measurement Interval) ____ 117 

4-24 Main-Effects Plot for Response y17 (Average Instantaneous Throughput of DD

Flows) ___________________________________________________________________ 118 

4-25 Main-Effects Plot for Response y20 (Average Instantaneous Throughput of FF Flows) 119 

4-26 Main-Effects Plot for PC1 (Network Congestion) _______________________________ 121 

4-27 Main-Effects Plot for PC2 (Network Delay) ____________________________________ 122 

4-28 Main-Effects Plot for PC3 (Throughput for Advantaged Flows) __________________ 123 

4-29 Main-Effects Plot for PC4 (Macroscopic Throughput) ___________________________ 124 

4-30 Multi-factor Scatter Plot of Smoothed Round Trip Time (y15) for each of the 11 

Experiment Factors _______________________________________________________ 130 

4-31 Multi-factor Scatter Plot of Relative Queuing Delay (y16) for Each Experiment 

Factor ___________________________________________________________________ 131 

4-32 Average Condition Ranking Displayed on Vertices of a Cube _____________________ 133 

 

5-1 Main Phases and Congestion Control Procedures in the Life of a TCP Flow ________ 138 

5-2 TCP Connection Establishment Procedures Leading to Connection Failure _________ 140 

5-3 TCP Connection Establishment Procedures Leading to Initiation of the Transfer 

Phase ___________________________________________________________________ 141 

 
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5-4 Sample Change in Congestion Window over Time under Standard Slow Start and 

Congestion Avoidance _____________________________________________________ 145 

5-5 Sample Change in Congestion Window over Time under Limited Slow Start and 

Congestion Avoidance _____________________________________________________ 146 

5-6 Simulated Dumbbell Topology for MesoNet Verification Experiments _____________ 162 

5-7 Change in cwnd vs. Time for Two TCP Flows (rtt = 42 ms) _______________________ 163 

5-8 Change in cwnd vs. Time for Two TCP Flows (rtt = 162 ms) ______________________ 164 

5-9 Change in cwnd vs. Time for Two TCP Flows (rtt = 324 ms) ______________________ 165 

5-10 Change in cwnd vs. Time for Two BIC Flows (rtt = 42 ms) _______________________ 165 

5-11 Change in cwnd vs. Time for Two BIC Flows (rtt = 162 ms) ______________________ 166 

5-12 Change in cwnd vs. Time for Two BIC Flows (rtt = 324 ms) ______________________ 166 

5-13 Change in cwnd vs. Time for Two CTCP Flows (rtt = 42 ms) ______________________ 167 

5-14 Change in cwnd vs. Time for Two CTCP Flows (rtt = 162 ms) _____________________ 168 

5-15 Change in cwnd vs. Time for Two CTCP Flows (rtt = 324 ms) _____________________ 168 

5-16 Change in cwnd vs. Time for Two FAST Flows (–tuning enabled, rtt = 42 ms) ______ 169 

5-17 Change in cwnd vs. Time for Two FAST Flows (–tuning enabled, rtt = 162 ms) _____ 169 

5-18 Change in cwnd vs. Time for Two FAST Flows (–tuning enabled, rtt = 324 ms) _____ 170 

5-19 Change in cwnd vs. Time for Two FAST Flows (F = 80, rtt = 42 ms) _______________ 170 

5-20 Change in cwnd vs. Time for Two FAST Flows (F = 80, rtt = 162 ms) ______________ 171 

5-21 Change in cwnd vs. Time for Two FAST Flows (F = 80, rtt = 324 ms) ______________ 171 

5-22 Change in cwnd vs. Time for Two FAST Flows (F = 200, rtt = 42 ms) ______________ 172 

5-23 Change in cwnd vs. Time for Two FAST Flows (F = 200, rtt = 162 ms) _____________ 172 

5-24 Change in cwnd vs. Time for Two FAST Flows (F = 200, rtt = 324 ms) _____________ 173 

5-25 Change in cwnd vs. Time for Two HSTCP Flows (rtt = 42 ms) ____________________ 174 

5-26 Change in cwnd vs. Time for Two HSTCP Flows (rtt = 162 ms) ___________________ 174 

5-27 Change in cwnd vs. Time for Two HSTCP Flows (rtt = 324 ms) ___________________ 175 

5-28 Change in cwnd vs. Time for Two H-TCP Flows (rtt = 42 ms) _____________________ 175 

5-29 Change in cwnd vs. Time for Two H-TCP Flows (rtt = 162 ms) ____________________ 176 

5-30 Change in cwnd vs. Time for Two H-TCP Flows (rtt = 324 ms) ____________________ 176 

5-31 Change in cwnd vs. Time for Two Scalable TCP Flows (rtt = 42 ms) _______________ 177 

5-32 Change in cwnd vs. Time for Two Scalable TCP Flows (rtt = 162 ms) ______________ 177 

5-33 Change in cwnd vs. Time for Two Scalable TCP Flows (rtt = 324 ms) ______________ 178 

 

6-1 Topology Adopted for Experiments __________________________________________ 184 

6-2 Scenario Adopted for Each Simulated Condition _______________________________ 188 

6-3 Dendrogram Illustrating Clustering Based on Responses for Condition 4 During Time 

Period One _______________________________________________________________ 200 

6-4 Cluster Analysis for 32 Conditions Using Data from Time Period One _____________ 201 

6-5 Conditions Ordered from Least to Most Congested vs. Retransmission Rate ________ 201 

6-6 Distribution of Flow States over Three Time Periods under Condition 4 for Standard 

TCP ____________________________________________________________________ 202 

6-7 Distribution of Flow States over Three Time Periods under Condition 5 for Standard 

TCP ____________________________________________________________________ 203 

6-8 Cluster Analysis for Time Period One ________________________________________ 203 

6-9 Sample Plot Analyzing the Influence of Condition and Congestion Control Algorithm 

on the Average Number of Active Flows ______________________________________ 204 

6-10 Summary of Statistically Significant Outliers in Time Period One _________________ 206 

6-11 Filtered Summary Plot for Time Period One Identifying Statistically Significant 

Outliers with Associated Relative Effect > 10% ________________________________ 207 

6-12 Average Per-Flow Goodput on DD Flows for Seven Congestion Control Algorithms 

under Condition 4 over Three Time Periods ___________________________________ 209 

6-13 Number of Active DD Flows for Seven Congestion Control Algorithms under 

Condition 4 over Three Time Periods _________________________________________ 210 

6-14 Aggregate Packet Delivery Rate DD Flows for Seven Congestion Control Algorithms 

under Condition 4 over Three Time Periods ___________________________________ 210 
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6-15 Analyzing the Influence of Condition and Congestion Control Algorithm on the 

Average Goodput for DD Flows (y9) during Time Period Two ____________________ 211 

6-16 Analyzing the Influence of Condition and Congestion Control Algorithm on 

Congestion Window Size during Time Period Three ____________________________ 212 

6-17 Cluster Analysis Using Data from Time Period One – Algorithm 3 Excluded ________ 213 

6-18 Screenshot from DiVisa Animation of the Temporal Evolution of a MesoNet 

Simulation _______________________________________________________________ 214 

6-19 Clustering for Time Period One – Annotated to Identify Distinctive Algorithm 3 ____ 215 

6-20 Clustering for Time Period One – Algorithm 3 Omitted _________________________ 216 

6-21 Condition-Response Summary for Time Period One ____________________________ 216 

6-22 Filtered Summary Plot for Time Period One Identifying Statistically Significant 

Outliers with Associated Relative Effect > 10% ________________________________ 217 

6-23 Detailed Analysis for Congestion Window Increase Rate in Time Period One _______ 218 

6-24 Detailed Analysis for Flow Completion Rate in Time Period One __________________ 218 

6-25 Detailed Analysis for Retransmission Rate in Time Period One ___________________ 219 

6-26 Detailed Analysis for NN Flow Completion Rate in Time Period One ______________ 219 

6-27 Detailed Analysis for Number of Connecting Flows in Time Period One ____________ 220 

6-28 Clustering for Time Period Two – Annotated to Identify Distinctive Algorithm 3 ____ 221 

6-29 Clustering for Time Period Two – Algorithm 3 Omitted _________________________ 221 

6-30 Condition-Response Summary for Time Period Two ____________________________ 222 

6-31 Filtered Summary Plot for Time Period Two Identifying Statistically Significant 

Outliers with Associated Relative Effect > 30% ________________________________ 222 

6-32 Detailed Analysis for Congestion Window Increase Rate in Time Period Two _______ 223 

6-33 Detailed Analysis for Flow Completion Rate in Time Period Two _________________ 224 

6-34 Detailed Analysis for Retransmission Rate in Time Period Two ___________________ 225 

6-35 Detailed Analysis for Average Goodput on DF Flows in Time Period Two __________ 225 

6-36 Detailed Analysis for Average Number of Active DF Flows in Time Period Two _____ 226 

6-37 Detailed Analysis for Average Number of Connecting Flows in Time Period Two ____ 226 

6-38 Detailed Analysis for Average Goodput on Long-lived Flow L1 in Time Period Two _ 227 

6-39 Detailed Analysis for Average Goodput on Long-lived Flow L2 in Time Period Two _ 227 

6-40 Clustering for Time Period Three – Annotated to Identify Distinctive Algorithm 3 ___ 228 

6-41 Clustering for Time Period Three – Algorithm 3 Omitted ________________________ 229 

6-42 Condition-Response Summary for Time Period Three __________________________ 229 

6-43 Filtered Summary Plot for Time Period Three Identifying Statistically Significant 

Outliers with Associated Relative Effect > 30% ________________________________ 230 

6-44 Detailed Analysis for Congestion Window Increase Rate in Time Period Three ______ 230 

6-45 Detailed Analysis for Flow Completion Rate in Time Period Three ________________ 231 

6-46 Detailed Analysis for Retransmission Rate in Time Period Three _________________ 231 

6-47 Detailed Analysis for Average Goodput on DF Flows in Time Period Three _________ 232 

6-48 Detailed Analysis for Average Number of Active DF Flows in Time Period Three ____ 232 

6-49 Detailed Analysis for Average Number of Connecting Flows in Time Period Three ___ 233 

6-50 Detailed Analysis for Average Congestion Window Size in Time Period Three ______ 233 

6-51 Detailed Analysis for Average Goodput on Long-lived Flow L2 in Time Period Three 234 

6-52 Clustering for Totals – Annotated to Identify Distinctive Algorithm 3 ______________ 235 

6-53 Clustering for Totals – Algorithm 3 Omitted ___________________________________ 236 

6-54 Condition-Response Summary for Totals _____________________________________ 236 

6-55 Detailed Analysis for Aggregate Number of Flows Completed over 25-minute 

Scenario _________________________________________________________________ 237 

6-56 Detailed Analysis for Average SYN Rate for Connecting Flows over 25-minute 

Scenario _________________________________________________________________ 237 

6-57 Five Time Series Showing the Distribution of Flow States over Three Time Periods 

for Algorithm 1 (BIC) under Condition 12 ____________________________________ 239 

6-58 Five Time Series Showing the Distribution of Flow States over Three Time Periods 

for Algorithm 1 (BIC) under Condition 21 ____________________________________ 240 

6-59 Reproduction of Fig. 5-22, Showing Change in cwnd for Two FAST Flows (F = 200, 

rtt = 42 ms) _______________________________________________________________ 241 
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6-60 Change in Congestion Window under FAST for Long-Lived Flow L2 during 500 

Measurement Intervals within TP2 under Condition 21 _________________________ 242 

6-61 Change in Congestion Window under TCP Reno for Long-Lived Flow L2 during 500 

Measurement Intervals within TP2 under Condition 21 _________________________ 243 

6-62 Change in Congestion Window under BIC for Long-Lived Flow L2 during 500 

Measurement Intervals within TP2 under Condition 21 _________________________ 243 

6-63 Change in Congestion Window under CTCP for Long-Lived Flow L2 during 500 

Measurement Intervals within TP2 under Condition 21 _________________________ 244 

6-64 Change in Congestion Window under HSTCP for Long-Lived Flow L2 during 500 

Measurement Intervals within TP2 under Condition 21 _________________________ 244 

6-65 Change in Congestion Window under HTCP for Long-Lived Flow L2 during 500 

Measurement Intervals within TP2 under Condition 21 _________________________ 245 

6-66 Change in Congestion Window under Scalable TCP for Long-Lived Flow L2 during 

500 Measurement Intervals within TP2 under Condition 21 ______________________ 245 

6-67 Average Congestion Window Size of DD Flows during TP3 under Condition 12 for 

BIC, FAST, HSTCP, HTCP, Scalable TCP and TCP Reno _______________________ 246 

6-68 Average Congestion Window Size of DD Flows during TP3 under Condition 12 for 

CTCP ___________________________________________________________________ 247 

6-69 Comparing Congestion Window Size of Scalable TCP (STCP) and FAST with respect 

to Falling Congestion Window ______________________________________________ 249 

 

7-1 Retransmission Rate vs. Simulated Conditions Ordered from Least to Most 

Congested ________________________________________________________________ 257 

7-2 Change in Flow States over Three Time Periods under Condition 3 for Standard TCP 258 

7-3 Change in Flow States over Three Time Periods under Condition 5 for Standard TCP 259 

7-4 Cluster Analysis for Time Period One ________________________________________ 260 

7-5 Detailed Analysis of Retransmission Rate in Time Period One for All Algorithms ____ 262 

7-6 Detailed Analysis of Retransmission Rate in Time Period One when Excluding 

Responses for Algorithm 3 __________________________________________________ 263 

7-7 Clustering for Time Period One – each sub-plot Annotated to Identify Distinctive 

Algorithms 3/8 ____________________________________________________________ 264 

7-8 Condition-Response Summary for Time Period One ____________________________ 265 

7-9 Condition-Response Summary for Time Period One – 10% Filter Applied _________ 266 

7-10 Detailed Analysis for Congestion Window Increase Rate Per Flow in Time Period One 267 

7-11 Detailed Analysis for Flow Completion Rate in Time Period One __________________ 267 

7-12 Detailed Analysis for Retransmission Rate in Time Period One ___________________ 268 

7-13 Detailed Analysis for Average Goodput on NN Flows in Time Period One __________ 268 

7-14 Detailed Analysis for NN Flow Completion Rate in Time Period One ______________ 269 

7-15 Detailed Analysis for Number of Connecting Flows in Time Period One ____________ 269 

7-16 Detailed Analysis for Average Packets Output Per 200 ms Interval in Time Period 

One _____________________________________________________________________ 270 

7-17 Detailed Analysis for Average Goodput on Long-lived Flow L2 in Time Period One __ 270 

7-18 Detailed Analysis for Average Buffer Utilization at Router K0a in Time Period One _ 271 

7-19 Cluster Analysis for Time Period Two – each sub-plot Annotated to Identify 

Distinctive Algorithms 3/8 __________________________________________________ 273 

7-20 Condition-Response Summary for Time Period Two ____________________________ 273 

7-21 Condition-Response Summary for Time Period Two – 30% Filter Applied _________ 274 

7-22 Detailed Analysis for Congestion Window Increase Rate in Time Period Two _______ 274 

7-23 Detailed Analysis for Packet Output Rate in Time Period Two ___________________ 275 

7-24 Detailed Analysis for Flow Completion Rate in Time Period Two _________________ 275 

7-25 Detailed Analysis for Retransmission Rate in Time Period Two ___________________ 276 

7-26 Detailed Analysis for Average Goodput on FN Flows in Time Period Two __________ 276 

7-27 Detailed Analysis for Average FN Flow Completion Rate during Time Period Two __ 277 

7-28 Detailed Analysis for Average Goodput on Long-lived Flow L2 in Time Period Two _ 277 

7-29 Detailed Analysis for Average Number of Connecting Flows during Time Period Two 278 

7-30 Detailed Analysis for Buffer Utilization at Router I0a during Time Period Two _____ 278 
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7-31 Cluster Analysis for Time Period Three – each sub-plot Annotated to Identify 

Distinctive Algorithms 3/8 __________________________________________________ 280 

7-32 Condition-Response Summary for Time Period Three __________________________ 280 

7-33 Condition-Response Summary for Time Period Three – 30% Filter Applied ________ 281 

7-34 Detailed Analysis of Congestion Window Increase Rate for Time Period Three ______ 281 

7-35 Detailed Analysis of Packet Output Rate for Time Period Three __________________ 282 

7-36 Detailed Analysis of Congestion Window Size for Time Period Three ______________ 282 

7-37 Detailed Analysis of Flow Completion Rate for Time Period Three ________________ 283 

7-38 Detailed Analysis of Retransmission Rate for Time Period Three _________________ 283 

7-39 Detailed Analysis of Average Goodput on Long-lived Flow L1 ____________________ 284 

7-40 Detailed Analysis of Buffer Utilization in Router C0a during Time Period Three ____ 284 

7-41 Detailed Analysis of Average Number of Connecting Flows during Time Period Three 285 

7-42 Cluster Analysis for Totals – each sub-plot Annotated to Identify Distinctive 

Algorithms 3/8 ____________________________________________________________ 286 

7-43 Condition-Response Summary for Totals _____________________________________ 286 

7-44 Detailed Analysis for Number of Packets Input during 25-minute Scenario _________ 287 

7-45 Detailed Analysis for Number of Packets Output during 25-minute Scenario ________ 288 

7-46 Detailed Analysis for Number of Flows Completed over 25-minute Scenario ________ 288 

7-47 Detailed Analysis for Average SYN Rate for Connecting Flows over 25-minute 

Scenario _________________________________________________________________ 289 

7-48 Detailed Analysis for Average Goodput on Completed DD Flows over 25-minute 

Scenario _________________________________________________________________ 289 

7-49 Change in Congestion Window under FAST-AT for Long-Lived Flow L2 during 500 

Measurement Intervals within TP2 under Condition 21 _________________________ 293 

7-50 Change in Congestion Window under TCP Reno for Long-Lived Flow L2 during 500 

Measurement Intervals within TP2 under Condition 21 _________________________ 294 

7-51 Goodput from t=4500 to t=6500 for each Congestion Control Algorithm on LongLived Flow L1 under Condition 8 ____________________________________________ 298 

7-52 Goodput from t=4500 to t=6500 for each Congestion Control Algorithm on LongLived Flow L2 under Condition 8 ____________________________________________ 300 

7-53 Goodput from t=4500 to t=6500 for each Congestion Control Algorithm on LongLived Flow L2 under Condition 8 ____________________________________________ 301 

7-54 Goodput from t=4500 to t=7500 for each Congestion Control Algorithm on LongLived Flow L1 under Condition 14 ___________________________________________ 305 

7-55 Goodput from t=4500 to t=7500 for each Congestion Control Algorithm on LongLived Flow L1 under Condition 28 ___________________________________________ 306 

7-56 Goodput from t=4500 to t=7500 for each Congestion Control Algorithm on LongLived Flow L1 under Condition 32 ___________________________________________ 307 

7-57 Goodput from t=4500 to t=7500 for each Congestion Control Algorithm on LongLived Flow L1 under Condition 21 ___________________________________________ 309 

7-58 Average Congestion Window Size of DD Flows during TP3 under Condition 8 for 

BIC, FAST, FAST-AT, HSTCP, HTCP, Scalable TCP and TCP Reno _____________ 311 

7-59 Average Congestion Window Size of DD Flows during TP3 under Condition 8 for 

CTCP ___________________________________________________________________ 312 

 

8-1 Conditions Ordered from Least to Most Congested (High Initial Slow-Start 

Threshold) _______________________________________________________________ 328 

8-2 Conditions Ordered from Least to Most Congested (Low Initial Slow-Start 

Threshold) _______________________________________________________________ 328 

8-3 Distribution of Flow States for Six Conditions (High Initial Slow-Start Threshold) ___ 329 

8-4 Distribution of Flow States for Six Conditions (Low Initial Slow-Start Threshold) ___ 330 

8-5 Illustration of Technique to Compute Means for Responses y1 to y11 ______________ 334 

8-6 Detailed Analysis of Retransmission Rate under High Initial Slow-Start Threshold __ 336 

8-7 Average Goodput for Flows Using Alternate Congestion Control Algorithm and 

Flows Using TCP when Transferring Movies on a Very Fast Path with a Fast 

Interface Speed Given a Low Initial Slow-Start Threshold _______________________ 337 
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8-8 Principal Components Analysis of Goodputs given High Slow-Start Threshold ______ 338 

8-9 Illustration of Biplot of PC1 vs. PC2 and Related Clustering _____________________ 339 

8-10 Scatter Plot of y16(u)/100 vs. y2(u)/100 for Movies Transferred over a Very Fast Path 

with Fast Interface Speed Given a High Initial Slow-Start Threshold; FAST Alternate 

Congestion Control Algorithm ______________________________________________ 340 

8-11 Bar Graph for Movies Transferred over a Very Fast Path with Fast Interface Speed 

given a High Initial Slow-Start Threshold during Condition 21 (Most Congested) ____ 340 

8-12 Rank Matrix for Algorithm 7 (Scalable TCP) – High Initial Slow-Start Threshold ___ 341 

8-13 Average Number of Active Flows under High Initial Slow-Start Threshold _________ 343 

8-14 Average Number of Connecting Flows under High Initial Slow-Start Threshold _____ 344 

8-15 Average Rate of Flow Completion under High Initial Slow-Start Threshold ________ 344 

8-16 Average Flow Retransmission Rate under High Initial Slow-Start Threshold _______ 345 

8-17 Average Smoothed Round-Trip Time under High Initial Slow-Start Threshold ______ 345 

8-18 Aggregate Flows Completed under High Initial Slow-Start Threshold _____________ 346 

8-19 Web Objects as Proportion of Flows Completed under High Initial Slow-Start 

Threshold ________________________________________________________________ 346 

8-20 Average Flow Congestion Window Size under High Initial Slow-Start Threshold ____ 347 

8-21 Average Number of Active Flows under Low Initial Slow-Start Threshold __________ 348 

8-22 Average Number of Connecting Flows under Low Initial Slow-Start Threshold _____ 349 

8-23 Average Rate of Flow Completion under Low Initial Slow-Start Threshold _________ 349 

8-24 Average Flow Retransmission Rate under Low Initial Slow-Start Threshold ________ 350 

8-25 Average Smoothed Round-Trip Time under Low Initial Slow-Start Threshold ______ 350 

8-26 Aggregate Flows Completed under Low Initial Slow-Start Threshold ______________ 351 

8-27 Web Objects as Proportion of Flows Completed under Low Initial Slow-Start 

Threshold ________________________________________________________________ 352 

8-28 Average Flow Congestion Window Size under Low Initial Slow-Start Threshold ____ 352 

8-29 Average Goodput on Movies (High Initial Slow-Start Threshold) _________________ 355 

8-30 Average Goodput on Service Packs (High Initial Slow-Start Threshold) ____________ 356 

8-31 Average Goodput on Documents (High Initial Slow-Start Threshold) ______________ 356 

8-32 Average Goodput on Web Objects (High Initial Slow-Start Threshold) ____________ 357 

8-33 Principal Component 1 vs. Principal Component 2 from Average Goodput Data 

(High Initial Slow-Start Threshold) __________________________________________ 357 

8-34 Scatter Plot of Goodput on TCP Flows vs. Non-TCP Flows for Movies Transferred on 

Very Fast Paths with Fast Interfaces (High Initial Slow-Start Threshold) ___________ 358 

8-35 32 Bar Graphs (one for each Simulated Condition) plotting Goodput on TCP Flows 

vs. Non-TCP Flows for Movies Transferred on Very Fast Paths with Fast Interfaces 

(High Initial Slow-Start Threshold) __________________________________________ 359 

8-36 Scatter Plot of Goodput on TCP Flows vs. Non-TCP Flows for Service Packs 

Transferred on Very Fast Paths with Fast Interfaces (High Initial Slow-Start 

Threshold) _______________________________________________________________ 360 

8-37 Scatter Plot of Goodput on TCP Flows vs. Non-TCP Flows for Documents 

Transferred on Very Fast Paths with Fast Interfaces (High Initial Slow-Start 

Threshold) _______________________________________________________________ 360 

8-38 Average Goodput on Movies (Low Initial Slow-Start Threshold) __________________ 363 

8-39 Average Goodput on Service Packs (Low Initial Slow-Start Threshold) ____________ 363 

8-40 Average Goodput on Documents (Low Initial Slow-Start Threshold) ______________ 364 

8-41 Average Goodput on Web Objects (Low Initial Slow-Start Threshold) _____________ 364 

8-42 Principal Component 1 vs. Principal Component 2 for Average Goodput Data (Low 

Initial Slow-Start Threshold) ________________________________________________ 365 

8-43 Scatter Plot of Goodput on TCP Flows vs. Non-TCP Flows for Movies Transferred on 

Very Fast Paths with Fast Interfaces (Low Initial Slow-Start Threshold) ___________ 366 

8-44 32 Bar Graphs (one for each simulated condition) plotting Goodput on TCP Flows vs. 

Non-TCP Flows for Movies Transferred on Very Fast Paths with Fast Interfaces 

(Low Initial Slow-Start Threshold) ___________________________________________ 367 

 

 
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8-45 Scatter Plot of Goodput on TCP Flows vs. Non-TCP Flows for Service Packs 

Transferred on Very Fast Paths with Fast Interfaces (Low Initial Slow-Start 

Threshold) _______________________________________________________________ 368 

8-46 Bar Graphs plotting Goodput on TCP Flows vs. Non-TCP Flows for Service Packs 

Transferred on Very Fast Paths with Fast Interfaces (Low Initial Slow-Start 

Threshold) _______________________________________________________________ 368 

8-47 Scatter Plot of Goodput on TCP Flows vs. Non-TCP Flows for Documents 

Transferred on Very Fast Paths with Fast Interfaces (Low Initial Slow-Start 

Threshold) _______________________________________________________________ 369 

8-48 32 Bar Graphs plotting Goodput on TCP Flows vs. Non-TCP Flows for Service Packs 

Transferred on Very Fast Paths with Fast Interfaces (Low Initial Slow-Start 

Threshold) _______________________________________________________________ 369 

8-49 Goodput Rank Matrix – y2(u) – BIC (High Initial Slow-Start Threshold) __________ 372 

8-50 Goodput Rank Matrix – y2(u) – CTCP (High Initial Slow-Start Threshold) _________ 373 

8-51 Goodput Rank Matrix – y2(u) – FAST (High Initial Slow-Start Threshold) _________ 373 

8-52 Goodput Rank Matrix – y2(u) – FAST-AT (High Initial Slow-Start Threshold) ______ 374 

8-53 Goodput Rank Matrix – y2(u) – HSTCP (High Initial Slow-Start Threshold) _______ 374 

8-54 Goodput Rank Matrix – y2(u) – HTCP (High Initial Slow-Start Threshold) _________ 375 

8-55 Goodput Rank Matrix – y2(u) – Scalable TCP (High Initial Slow-Start Threshold) __ 375 

8-56 TCP Goodput Rank Matrix – y16(u) – BIC (High Initial Slow-Start Threshold) _____ 376 

8-57 TCP Goodput Rank Matrix – y16(u) – CTCP (High Initial Slow-Start Threshold) ___ 376 

8-58 TCP Goodput Rank Matrix – y16(u) – FAST (High Initial Slow-Start Threshold) ___ 377 

8-59 TCP Goodput Rank Matrix – y16(u) – FAST-AT (High Initial Slow-Start Threshold) 377 

8-60 TCP Goodput Rank Matrix – y16(u) – HSTCP (High Initial Slow-Start Threshold) __ 378 

8-61 TCP Goodput Rank Matrix – y16(u) – HTCP (High Initial Slow-Start Threshold) ___ 378 

8-62 TCP Goodput Rank Matrix – y16(u) – Scalable TCP (High Initial Slow-Start 

Threshold) _______________________________________________________________ 379 

8-63 Goodput Rank Matrix – y2(u) – BIC (Low Initial Slow-Start Threshold) ___________ 380 

8-64 Goodput Rank Matrix – y2(u) – CTCP (Low Initial Slow-Start Threshold) _________ 381 

8-65 Goodput Rank Matrix – y2(u) – FAST (Low Initial Slow-Start Threshold) _________ 381 

8-66 Goodput Rank Matrix – y2(u) – FAST-AT (Low Initial Slow-Start Threshold) ______ 382 

8-67 Goodput Rank Matrix – y2(u) – HSTCP (Low Initial Slow-Start Threshold) ________ 382 

8-68 Goodput Rank Matrix – y2(u) – HTCP (Low Initial Slow-Start Threshold) _________ 383 

8-69 Goodput Rank Matrix – y2(u) – Scalable TCP (Low Initial Slow-Start Threshold) ___ 383 

8-70 TCP Goodput Rank Matrix – y16(u) – BIC (Low Initial Slow-Start Threshold) _____ 384 

8-71 TCP Goodput Rank Matrix – y16(u) – CTCP (Low Initial Slow-Start Threshold) ____ 384 

8-72 TCP Goodput Rank Matrix – y16(u) – FAST (Low Initial Slow-Start Threshold) ____ 385 

8-73 TCP Goodput Rank Matrix – y16(u) – FAST-AT (Low Initial Slow-Start Threshold) 385 

8-74 TCP Goodput Rank Matrix – y16(u) – HSTCP (Low Initial Slow-Start Threshold) __ 386 

8-75 TCP Goodput Rank Matrix – y16(u) – HTCP (Low Initial Slow-Start Threshold) ___ 386 

8-76 TCP Goodput Rank Matrix – y16(u) – Scalable TCP (Low Initial Slow-Start 

Threshold) _______________________________________________________________ 387 

8-77 Average vs. Standard Deviation in Goodput Rank (High Initial Slow-Start Threshold) 388 

8-78 Average vs. Standard Deviation in Goodput Rank Low Initial Slow-Start Threshold)_ 389 

 

9-1 Conditions Ordered Least to Most Congested under High Initial Slow-Start 

Threshold ________________________________________________________________ 399 

9-2 Distribution of Flow States for Six Conditions with Increasing Congestion __________ 399 

9-3 Average Number of Connecting Flows under High Initial Slow-Start Threshold _____ 402 

9-4 Average Retransmission Rate under High Initial Slow-Start Threshold ____________ 403 

9-5 Average Flow Completion Rate under High Initial Slow-Start Threshold ___________ 404 

9-6 Aggregate Flows Completed under High Initial Slow-Start Threshold _____________ 404 

9-7 Average Smoothed Round-Trip Time under High Initial Slow-Start Threshold ______ 405 

9-8 Web Objects as Proportion of Flows Completed under High Initial Slow-Start 

Threshold ________________________________________________________________ 405 

9-9 Movies as Proportion of Flows Completed under High Initial Slow-Start Threshold __ 406 
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9-10 Average Flow Congestion Window Size under High Initial Slow-Start Threshold ____ 406 

9-11 Average Goodputs on Movies under Combinations of Path Class and Interface Speed 409 

9-12 Average Goodputs on Service Packs under Combinations of Path Class and Interface 

Speed ___________________________________________________________________ 409 

9-13 Average Goodputs on Documents under Combinations of Path Class and Interface 

Speed ___________________________________________________________________ 410 

9-14 Average Goodputs on Web Objects under Combinations of Path Class and Interface 

Speed ___________________________________________________________________ 410 

9-15 Principal Component 1 vs. Principal Component 2 from Average Goodput Data in a 

Large, Fast Network and High Initial Slow-Start Threshold ______________________ 411 

9-16 Goodput on TCP Flows vs. Non-TCP Flows for Movies on Very Fast Paths with Fast 

Interfaces in a Large, Fast Network with High Initial Slow-Start Threshold ________ 412 

9-17 Bar Graphs plotting Goodput Differences on TCP Flows vs. Non-TCP Flows for 

Movies Transferred on Very Fast Paths with Fast Interfaces in a Large, Fast Network 

with a High Initial Slow-Start Threshold ______________________________________ 413 

9-18 Goodput on TCP Flows vs. Non-TCP Flows for Movies on Fast Paths with Fast 

Interfaces in a Large, Fast Network with High Initial Slow-Start Threshold ________ 414 

9-19 Bar Graphs plotting Goodput Differences on TCP Flows vs. Non-TCP Flows for 

Movies Transferred on Fast Paths with Fast Interfaces in a Large, Fast Network with 

High Initial Slow-Start Threshold ____________________________________________ 414 

9-20 Goodput on TCP Flows vs. Non-TCP Flows for Service Packs on Fast Paths with Fast 

Interfaces in a Large, Fast Network with High Initial Slow-Start Threshold ________ 415 

9-21 Bar Graphs plotting Goodput Differences on TCP Flows vs. Non-TCP Flows for 

Service Packs Transferred on Fast Paths with Fast Interfaces in a Large, Fast 

Network with High Initial Slow-Start Threshold _______________________________ 415 

9-22 Goodput Rank Matrix – y2(u) – BIC (Large, Fast Network, High Initial Slow-Start) _ 418 

9-23 Goodput Rank Matrix – y2(u) – CTCP (Large, Fast Network, High Initial Slow-Start) 419 

9-24 Goodput Rank Matrix – y2(u) – FAST (Large, Fast Network, High Initial Slow-Start) 419 

9-25 Goodput Rank Matrix – y2(u) – FAST-AT (Large, Fast Network, High Initial SlowStart) ___________________________________________________________________ 420 

9-26 Goodput Rank Matrix – y2(u) – HSTCP (Large, Fast Network, High Initial SlowStart) ___________________________________________________________________ 420 

9-27 Goodput Rank Matrix – y2(u) – HTCP (Large, Fast Network, High Initial Slow-Start) 421 

9-28 Goodput Rank Matrix – y2(u) – Scalable (Large, Fast Network, High Initial SlowStart) ___________________________________________________________________ 421 

9-29 Goodput Rank Matrix – y16(u) – BIC (Large, Fast Network, High Initial Slow-Start) 422 

9-30 Goodput Rank Matrix – y16(u) – CTCP (Large, Fast Network, High Initial SlowStart) ___________________________________________________________________ 422 

9-31 Goodput Rank Matrix – y16(u) – FAST (Large, Fast Network, High Initial SlowStart) ___________________________________________________________________ 423 

9-32 Goodput Rank Matrix – y16(u) – FAST-AT (Large, Fast Network, High Initial SlowStart) ___________________________________________________________________ 423 

9-33 Goodput Rank Matrix – y16(u) – HSTCP (Large, Fast Network, High Initial SlowStart) ___________________________________________________________________ 424 

9-34 Goodput Rank Matrix – y16(u) – HTCP (Large, Fast Network, High Initial SlowStart) ___________________________________________________________________ 424 

9-35 Goodput Rank Matrix – y16(u) – Scalable (Large, Fast Network, High Initial SlowStart) ___________________________________________________________________ 425 

9-36 Average vs. Standard Deviation in Goodput Rank (Large, Fast Network, High Initial 

Slow-Start Threshold) _____________________________________________________ 426 

 

A-1 Response curves of two hypothetical TCP variants TCP0 and TCP1 and the graph of 

a hypothetical packet loss function ___________________________________________ 471 

A-2 Response curve for CUBIC with a ±50% error region vs. TCP Reno _______________ 477 

A-3 Response curve for CTCP with a ±50% error region vs. TCP Reno ________________ 478 

A-4 Response curves for CUBIC and CTCP with corresponding error regions __________ 479 
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B-1 Experiment Topology ______________________________________________________ 484

B-2 Changes in RTT Fairness with Increasing Buffer Size ___________________________ 489

B-3 Changes in Throughput Fairness with Increasing Buffer Size ____________________ 490

B-4 Changes in Average Throughput with Increasing Buffer Size _____________________ 491

 

C-1 Combined Matrix of Scatter Plots and Correlation Values for 22 Responses ________ 500

C-2 Frequency Distribution of the Absolute Value of Correlations for All Pairs of 

Responses ________________________________________________________________ 501

C-3 Index-Index Plot for Correlation Pairs where |Correlation (Yi, Yj)| > 0.65 ___________ 502

C-4 Histograms for 22 Principal Components _____________________________________ 503

C-5 Weight Vectors for the First Four Principal Components ________________________ 503

C-6 Main Effects Plots for Top Four Principal Components _________________________ 504

C-7 Y-Y-X plot for Responses y7 and y22 _________________________________________ 506

C-8 Main-Effects Plot for Response y1 (Average Number of Active Flows) _____________ 507

C-9 Main-Effects Plot for Response y10 (Average Retransmission Rate) _______________ 508

C-10 Main-Effects Plot for Response y11 (Average Congestion Window Size) ____________ 509

C-11 Main-Effects Plot for Response y22 (Average Throughput on NN Flows) ___________ 510

C-12 Main-Effects Plot for Response y15 (Average Smoothed Round-Trip Time) _________ 511

C-13 Main-Effects Plot for Response y4 (Average Packets Output per Measurement 

Interval) _________________________________________________________________ 512

C-14 Main-Effects Plot for Response y6 (Flows Completed per Measurement Interval) ____ 513

C-15 Main-Effects Plot for Response y17 (Average Instantaneous Throughput on DD

Flows) ___________________________________________________________________ 514

C-16 Main-Effects Plot for Response y20 (Average Instantaneous Throughput on FF

Flows) ___________________________________________________________________ 515

C-17 Average Condition Ranking Displayed on Vertices of a Cube _____________________ 518

D-1 Sample Ordered Data Plot __________________________________________________ 524

D-2 Sample Multi-factor Scatter Plot _____________________________________________ 526

D-3 Sample Main Effects Plot ___________________________________________________ 527

D-4 Sample Interaction Effects Matrix ___________________________________________ 528

D-5 Sample Block Plots ________________________________________________________ 529

D-6 Sample Youden Plot _______________________________________________________ 530

D-7 Sample |Effects| Plot _______________________________________________________ 531

D-8 Sample Half-Normal Probability Plot of |Effects| _______________________________ 532

D-9 Sample Cumulative Residual Standard Deviation Plot __________________________ 533

D-10 Sample Contour Plot of Two Dominant Factors ________________________________ 534
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Mills, et al. Special Publication 500-282 xxvi 

List of Tables 

3-1 Link Propagation Delays in the Base Simulated Topology ________________________ 41 

3-2 Routes across the Backbone from Source (S) to Destination (D) Domain ____________ 41 

3-3 Specification of Values for Parameter SOURCE_TYPE _________________________ 48 

3-4 Summary of Aggregate Measures Reported by MesoNet _________________________ 53 

3-5 Summary of Flow-Class Measures Reported by MesoNet ________________________ 56 

3-6 Summary of Long-Lived Flow Measures Reported by MesoNet ___________________ 58 

3-7 Summary of Measures Reported by MesoNet for Each Router ____________________ 59 

3-8 Summary of Added Measures Reported by MesoNet for Access Routers ___________ 60 

3-9 Characteristic Performance for MesoNet in Two Experiments ____________________ 68 

3-10 Processing Requirements for MesoNet in Two Experiments ______________________ 69 

3-11 Memory Requirements for MesoNet in Two Experiments ________________________ 69 

 

4-1 Responses Characterizing Macroscopic Network Behavior _______________________ 78 

4-2 Responses Characterizing Instantaneous Throughput for Active Flows by Flow Class 79 

4-3 Identity and Purpose of 10 Plots in the 10-Step Graphical Analysis ________________ 86 

4-4 Simulation-Control Parameters _____________________________________________ 90 

4-5 Parameters Controlling User Behavior _______________________________________ 90 

4-6 Parameters Adapting Network Characteristics _________________________________ 91 

4-7 Parameters Altering Properties of Sources and Receivers ________________________ 92

4-8 Parameters Controlling Source Startup Pattern ________________________________ 92 

4-9 Parameters Related to TCP Operation ________________________________________ 93 

4-10 Recap of Sensitivity Analysis Factors and Mapping to MesoNet Parameters ________ 93 

4-11 Two-Level Settings for Each of 11 Factors in Sensitivity Analysis _________________ 94 

4-12 Relationship among the Speed of Backbone Routers and Other Router Types _______ 95 

4-13 Relation between Factors and Number and Distribution of Sources _______________ 97 

4-14 Relation between Factors and Number and Distribution of Receivers ______________ 97 

4-15 Relation between Factors and Distribution of Flow Classes ______________________ 97 

4-16 Buffers for Combinations of Round-Trip Propagation Delay (x1) and Capacity (x2) __ 98 

4-17 Characteristics of Processors Executing Simulation Runs ________________________ 99 

4-18 Execution Time Required for Each Simulation Run _____________________________ 101 

4-19 Responses Selected for Investigation in Sensitivity Analysis ______________________ 107 

4-20 Responses Composing Principal Component One _______________________________ 109 

4-21 Responses Composing Principal Component Two ______________________________ 109 

4-22 Responses Composing Principal Component Three _____________________________ 109 

4-23 Responses Composing Principal Component Four ______________________________ 110 

4-24 Definition of Major Principal Components in Model Response ___________________ 119 

4-25 Rank Analysis based on Domain Expertise ____________________________________ 127 

4-26 Rank Analysis based on Principal Components Analysis ________________________ 127 

4-27 Mapping of Factor Settings to Eight Three-Factor Conditions ____________________ 131 

4-28 Average Response Values for Each Three-Factor Condition ______________________ 131 

4-29 Ranking for Each Condition vs. Each Response ________________________________ 132 

4-30 Changes in Ranking Attributable to Each Factor _______________________________ 132 

 

5-1 Definition of Symbols Used to Model Connection Establishment Procedures ________ 141 

5-2 Definition of Symbols Used to Model Slow-Start Procedures _____________________ 142 

5-3 Symbols and Definitions Used to Model BIC Congestion Avoidance Procedures _____ 147 

5-4 Symbols and Definitions Used to Model CTCP Congestion Avoidance Procedures ___ 150 

5-5 Symbols and Definitions Used to Model FAST Congestion Avoidance Procedures ___ 153 

5-6 Symbols and Definitions Used to Model HSTCP Congestion Avoidance Procedures __ 155 

5-7 Symbols and Definitions Used to Model H-TCP Congestion Avoidance Procedures __ 156 

5-8 Symbols and Definitions Used to Model Scalable TCP Congestion Avoidance 

Procedures _______________________________________________________________ 158 
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5-9 Capacity of the Dumbbell Topology with Various Round-Trip Times ______________ 179 

5-10 Link and Buffer Utilizations for Simulated Congestion Control Mechanisms ________ 180 

5-11 Bandwidth Fairness (Jain’s Index) for Simulated Congestion Control Mechanisms __ 180 

 

6-1 Congestion Control Mechanisms Compared ___________________________________ 183 

6-2 Definition of Three Path Classes _____________________________________________ 184 

6-3 Robustness Factors Selected for Comparing Congestion Control Mechanisms _______ 185 

6-4 Fixed Network Parameters _________________________________________________ 185 

6-5 Domain View of Router Speeds ______________________________________________ 186 

6-6 Path Propagation Delays Simulated __________________________________________ 186 

6-7 Buffer Sizes Simulated _____________________________________________________ 186 

6-8 Fixed Parameters Related to Sources and Receivers ____________________________ 187 

6-9 Number of Simulated Sources _______________________________________________ 187 

6-10 Fixed Simulation Control Parameters ________________________________________ 187 

6-11 Fixed Parameters Specifying Simulated User Traffic ____________________________ 188 

6-12 Fixed Parameters Specifying Long-Lived Flows ________________________________ 189 

6-13 Template Specifying a 26-1 Orthogonal Fractional Factorial Design ________________ 190 

6-14 Instantiated Robustness Conditions for 26-1 Experiment Design ___________________ 191 

6-15 Responses Characterizing Macroscopic Behavior _______________________________ 191 

6-16 Responses Characterizing User Experience on Very Fast Paths ___________________ 192 

6-17 Responses Characterizing User Experience on Fast Paths ________________________ 192 

6-18 Responses Characterizing User Experience on Typical Paths _____________________ 193 

6-19 Responses Characterizing User Experience on Long-Lived Flows _________________ 193 

6-20 Responses Charactering Buffer Usage in Directly Connected Access Routers _______ 193 

6-21 Aggregate Responses Characterizing Macroscopic Behavior _____________________ 194 

6-22 Responses Characterizing User Experience for Completed Flows on Very Fast Paths _ 194 

6-23 Responses Characterizing User Experience for Completed Flows on Fast Paths _____ 194 

6-24 Responses Characterizing User Experience for Completed Flows on Typical Paths ___ 195 

6-25 Responses Characterizing Distribution of Flows among Backbone Routers _________ 195 

6-26 Characteristics of Compute Servers Used to Execute the Simulations ______________ 196 

6-27 Processing Requirements for Simulations Mapped to Specific Compute Servers _____ 196 

6-28 Characterization of the Number of Flows and Data Packets Simulated _____________ 197 

6-29 Format Adopted for Each Time-Period Data File _______________________________ 197 

6-30 Format Adopted for Reporting Aggregate Measures ____________________________ 198 

6-31 Flows Completed per 200 ms interval and Total Completions for DD Flows in Time 

Period Two under Condition 4 ______________________________________________ 211 

6-32 Average, Minimum and Maximum Goodput on DD Flows for Each Congestion 

Control Algorithm during TP2 when Averaged over All 32 Conditions _____________ 240 

 

7-1 Congestion Control Mechanisms Compared ___________________________________ 253 

7-2 Robustness Factors Adopted for Comparing Congestion Control Mechanisms ______________ 254 

7-3 Fixed Parameters Related to Sources and Receivers ____________________________ 255 

7-4 Instantiated Robustness Conditions __________________________________________ 255 

7-5 Domain View of Router Speeds ______________________________________________ 256 

7-6 Number of Simulated Sources _______________________________________________ 256 

7-7 Buffer Sizes Simulated _____________________________________________________ 256 

7-8 Comparing Resource Requirements for Simulating the FAST Congestion Control 

Algorithm in a Large, Fast Network and a Scaled-Down Network _________________ 261 

7-9 Comparing Number of Simulated Flows and Packets for a Large, Fast Network and a 

Scaled-Down Network under All Congestion Control Algorithms _________________ 261 

7-10 Goodputs on DD Flows Averaged over all 32 Conditions for Each Time Period ______ 292 

7-11 Per Flow Goodputs for Long-Lived Flow L1 Averaged over all 32 Conditions for 

Each Time Period _________________________________________________________ 295 

7-12 Per Flow Goodputs for Long-Lived Flow L2 Averaged over all 32 Conditions for 

Each Time Period _________________________________________________________ 295 

 
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7-13 Per Flow Goodputs for Long-Lived Flow L3 Averaged over all 32 Conditions for 

Each Time Period _________________________________________________________ 295 

7-14 Time until Long-Lived Flows Reach Maximum Transfer Rate in TP1 for Condition 8 296 

7-15 Time until Long-Lived Flows Recover Maximum Transfer Rate in TP3 for 

Condition 8 ______________________________________________________________ 297 

7-16 Average Goodput for Each Congestion Control Algorithm on Three Long-Lived 

Flows during TP2 under Condition 8 _________________________________________ 302 

7-17 Time until Long-Lived Flow L1 Reaches Maximum Transfer Rate in TP1 for Three 

Uncongested Conditions ____________________________________________________ 303 

7-18 Time until Long-Lived Flow L1 Recovers Maximum Transfer Rate in TP3 for Three 

Uncongested Conditions ____________________________________________________ 303 

7-19 Average Goodput on Long-Lived Flow L1 for Each Congestion Control Algorithm 

under Each of Three Uncongested Conditions _________________________________ 308 

7-20 Average Goodput on Long-Lived Flow L1 for Each Congestion Control Algorithm in 

Each of the Three Time Periods under Most Congested Condition 21 _____________ 308 

 

8-1 Alternate Congestion Control Regimes Compared ______________________________ 316 

8-2 Robustness Factors Adopted for Comparing Congestion Control Mechanisms ______________ 317 

8-3 Probability Distributions for Files of Various Sizes _____________________________ 318 

8-4 Fixed Parameters for Sizing Files ____________________________________________ 318 

8-5 Four Dimensions Defining Flow Groups ______________________________________ 318 

8-6 Flow Group Identifiers Assigned Based on Three-Dimensional Classification _______ 319 

8-7 Computing Target Minimums for Document Transfers with Combinations of Flow 

Traits ___________________________________________________________________ 321 

8-8 Fixed Network Parameters _________________________________________________ 322 

8-9 Fixed Source and Receiver Parameters _______________________________________ 323 

8-10 Proportion of Sources and Receivers Placed under Specific Router Classes _________ 323 

8-11 Probability of Flows Transiting Specific Path Classes ___________________________ 323 

8-12 Fixed Simulation Control Parameters ________________________________________ 324 

8-13 Two-Factor 29-4 Orthogonal Fractional Factorial Design Template ________________ 325 

8-14 The 32 Simulated Conditions used to compare Each Combination of Congestion 

Control Algorithm and Initial-Slow Start Threshold ____________________________ 326 

8-15 Simulated Router Speeds ___________________________________________________ 327 

8-16 Number of Simulated Sources _______________________________________________ 327 

8-17 Simulated Propagation Delays _______________________________________________ 327 

8-18 Characterization of Simulated Buffer Sizes ____________________________________ 327 

8-19 Measured Responses Characterizing Macroscopic Network Behavior ______________ 331 

8-20 Measured Responses Characterizing User Experience for Each Flow Group ________ 332 

8-21 Comparing Resource Requirements for Simulating One Hour of Network Operation 

under 32 Conditions with High and Low Initial Slow-Start Thresholds _____________ 333 

8-22 Comparing Flows Completed and Data Packets Sent when Simulating One Hour of 

Network Operation under 32 Conditions with High and Low Initial Slow-Start 

Thresholds _______________________________________________________________ 333 

8-23 Data Format Summarizing Responses y1 to y16 for All Algorithms and Conditions __ 334 

8-24 Data Format Summarizing User Experience for One Flow Group _________________ 335 

8-25 Data Format Summarizing User Experience for One Flow Group under All 

Algorithms and Conditions _________________________________________________ 335 

8-26 Average Goodput per Flow Group under Each Alternate Congestion Control 

Algorithm (High Initial Slow-Start Threshold) _________________________________ 353 

8-27 Average Goodput per Flow Group on TCP Flows Competing with Each Alternate 

Congestion Control Algorithm (High Initial Slow-Start Threshold) ________________ 354 

8-28 Average Goodput per Flow Group under Each Alternate Congestion Control 

Algorithm (Low Initial Slow-Start Threshold) _________________________________ 361 

8-29 Average Goodput per Flow Group on TCP Flows Competing with Each Alternate 

Congestion Control Algorithm (Low Initial Slow-Start Threshold)_________________ 362 

 
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8-30 Range of Goodput Differences (%) for Flow Groups under High and Low Initial 

Slow-Start Threshold ______________________________________________________ 370 

8-31 Summary Average and Standard Deviation in Goodput and TCP Goodput Rank for 

All Congestion Control Algorithms (High Initial Slow-Start Threshold) ____________ 379 

8-32 Summary Average and Standard Deviation in Goodput and TCP Goodput Rank for 

All Congestion Control Algorithms (Low Initial Slow-Start Threshold) ____________ 387 

 

9-1 Comparison of Experiment with Congestion Control Algorithms in a Small Network vs. 

Experiment in a Large, Fast Network _________________________________________________ 395 

9-2 Robustness Factors Adopted for Comparing Congestion Control Mechanisms ______ 396 

9-3 Key Fixed Factors Adopted for Comparing Congestion Control Mechanisms _______ 396 

9-4 Two-Level 29-4 Orthogonal Fractional Factorial Design __________________________ 397 

9-5 Simulated Router Speeds ___________________________________________________ 398 

9-6 Number of Simulated Sources _______________________________________________ 398 

9-7 Characterization of Simulated Buffer Sizes ____________________________________ 398 

9-8 Comparing Resource Requirements for Simulating a Small Network and a Large, 

Fast Network _____________________________________________________________ 400 

9-9 Comparing Number of Simulated Flows and Packets for a Small Network and a 

Large, Fast Network _______________________________________________________ 401 

9-10 Average Goodput per Flow Group under Each Alternate Congestion Control 

Algorithm for a Large, Fast Network with High Initial Slow-Start Threshold _______ 407 

9-11 Average Goodput per Flow Group on TCP Flows Competing with Each Alternate 

Algorithm for a Large, Fast Network with High Initial Slow-Start Threshold _______ 408 

9-12 Range of Goodput Differences (%) for Flow Groups under High Initial Slow-Start 

Threshold for Small, Slow Network and for Large, Fast Network _________________ 416 

9-13 Summary Average and Standard Deviation in Goodput Rankings for Flows using 

Alternate Congestion Control Algorithms and for Competing TCP Flows (Large, Fast 

Network, High Initial Slow-Start Threshold) __________________________________ 425 

 

10-1 Comparing Four Characteristics of Individual Alternate Congestion Control 

Algorithms _______________________________________________________________ 436 

 

A-1 Estimated throughput for CUBIC in p/ms for 1000 concurrent flows on a link with a 

122 p/ms capacity (for 1 KB packets) _________________________________________ 480 

A-2 Estimated throughput for CTCP in p/ms for 1000 concurrent flows on a link with a 

122 p/ms capacity (for 1KB packets) _________________________________________ 480 

A-3 Estimated throughput for TCP Reno in p/ms for 1000 concurrent flows on a link with 

a 122 p/ms capacity (for 1 KB packets) _______________________________________ 480 

 

B-1 One-Way Propagation Delay on Each Link in the Simulated Topology _____________ 485 

B-2 Characteristics of Three Flow Sets Simulated in the Experiment __________________ 486 

B-3 MesoNet Parameter Settings for the Experiment _______________________________ 486 

B-4 Domain View of the Simulated Network Characteristics _________________________ 487 

B-5 Configuration of Compute Server for Simulations ______________________________ 488 

B-6 Resource Requirements for Simulations ______________________________________ 488 

 

C-1 Two-Level Settings for Each of 11 Factors in Sensitivity Analysis _________________ 494 

C-2 Selected Fixed Parameters _________________________________________________ 495 

C-3 Router Speeds by Router Class for Each Level of Network Speed (x2) ____________ 495 

C-4 Average Buffer Size by Router Class for Specific Combinations of Propagation Delay 

(x1), Network Speed (x2) and Buffer-Sizing Algorithm (x3) ______________________ 495 

C-5 Relation between Factors and Number and Distribution of Sources _______________ 496 

C-6 Relation between Factors and Number and Distribution of Receivers ______________ 497 

C-7 Relation between Factors and Distribution of Flow Classes ______________________ 497 

C-8 Responses Characterizing Macroscopic Network Behavior _______________________ 498 

C-9 Responses Characterizing Average Instantaneous Throughput by Flow Class _______ 498 
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C-10 Configuration of Compute Servers for Simulations _____________________________ 499 

C-11 Execution Time Required for Each Simulation Run ____________________________ 499 

C-12 Responses Selected for Investigation in Sensitivity Analysis ______________________ 506 

C-13 Rank Analysis of Sensitivity Analysis Responses _______________________________ 516 

C-14 Mapping of Factor Settings to Eight Conditions ________________________________ 517 

C-15 Average Response Values for Each Condition __________________________________ 517 

C-16 Ranking for Each Condition vs. Each Response ________________________________ 518 

C-17 Changes in Ranking Attributable to Each Factor _______________________________ 519 

 

D-1 Identity and Purpose of 10 Plots in the 10-Step Graphical Analysis ________________ 523 
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 Table of Acronyms 

Acronym Definition

ACK Acknowledgment

AvFSWO Average File Size for Web Objects

AvThT Average Think Time

AWND Advertised Window

BIC Binary Increase Congestion control

BRS Backbone Router Speed

C Capacity

CA Cellular Automata

CAC Correlation Analysis and Clustering

CPU Central Processing Unit

CRTO Current Retransmission Time Out

CTCP Compound TCP

CWND Congestion Window

DES Discrete‐Event Simulation

DT Data segment (or packet)

DWND Delay Window (used by CTCP)

FAST Fast Active Queue Management Scalable TCP

FAST‐AT Fast Active Queue Management Scalable TCP with Alpha Tuning

GB Gigabytes (Giga denotes billion)

Gbps Gigabits per second (Giga denotes billion)

GENI Global Environment for Network Innovation

GHz Giga Hertz (Giga denotes billion)

HSTCP High Speed TCP

HTCP Hamilton TCP

ICCRG Internet Congestion Control Research Group

IP Internet Protocol

IRTF Internet Research Task Force

ISP Internet Service Provider

ITL Information Technology Laboratory

Kbytes Kilobtyes

Kbytes Kilobytes

MB Megabytes

Mbps Megabits per second

Mbytes Megabytes

MCMP Multicore Multiprocessor

NAK Negative Acknowledgment

NIST National Institute of Standards and Technology

NSF National Science Foundation

OFF Orthogonal Fractional Factorial

P2P Peer‐to‐Peer
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Mills, et al. Special Publication 500-282 xxxii 

PC Personal Computer

PC Principal Component

PCA Principal Components Analysis

PDM Propagation Delay in Milliseconds  

POP Point Of Presence

ppts packets per time step

pps packets per second

p/ms packets per millisecond

PrFH Probability of a Fast Host

PrLF Probability of a Larger File

QSA Queue Sizing Algorithm

RDist Receiver Distribution

RTO Retransmission Time Out

RTT Round Trip Time

RWND Receiver Window

SD Standard Deviation

SDist Source Distribution

SFSR Scaling For Sources and Receivers

SLX Simulation Language with eXtensibility

SQR Square Root

SQRT Square Root

SRTT Smoothed Round Trip Time

SST slow start threshold

STCP Scalable TCP

TCP Transmission Control Protocol

UDP User Datagram Protocol

WEB World‐wide Web