Rate-Based Active Queue Management with Priority Classes for Better Video Transmission

1. Rate-Based Active Queue Management with Priority Classesfor Better Video Transmission Jae Chung and Mark Claypool Computer Science Department Worcester Polytechnic Institute Worcester, Massachusetts, USA http://perform.wpi.edu/

2. Streaming Media Applications • Can use TCP • Hides network information • Difficult to use media scaling upon • Hard to control transmission timing • Higher jitter due to traffic burst • Often use UDP • Control the flow as desired • Responsiveness, Fairness • Can tolerate some frame losses • Trickier for Video Streaming WPI

3. B B P B B I B B P B B I A Sample MPEG Stream Difficulty of Video Streaming • Inter-frame dependencies (Compression) • Large frames: fragmented in IP layer I WPI

4. Outline • Introduction • Approaches • Rb-RIO • Experiments • Results • Summary WPI

5. Approaches to The Problem • Application Support • Redundancy and Error Correction • Media Scaling • Network Architectural Support • Integrated Services (IntServ) • Differentiated Services (DiffServ) • Router Support • Resource Reservation (WFQ, …) • Priority Class-Based Queue Management WPI

6. Basic Idea: Avoid Domino Frame Loss Using Priority Queuing • Queue supports 3 priority class • Drop all the lowest class packets before starting to drop the next class packets • MPEG Video Frame Mapping • Map I-, P- and B-frame packets to High, Mid and Low priority classes • TCP Mapping • Randomly map TCP packets to the 3 classes (standalone better-than-best-effort Queue) WPI

7. Average Queue Size Based Rate Based … RED RIO … Rb-RED Rb-RIO AQM Support for Priority-Classes • Detect Congestion • Determine Degree • Notify Sources Active Queue Management WPI

8. EAR SR Rb-RED • Components • Limit: Queue Limit • Q: Queue Size • EAR: Estimated Arrival Rate • SR: Service Rate • Drop Logic (for incoming packets) • if (Q > Limit) • Drop • else if (EAR > SR) • Drop with P = (EAR – SR) / EAR WPI

9. EARlow EARmid EAR EARhigh SR EARlow EARlow EARmid EAR EAR EARmid SR EARhigh SR EARhigh Rb-RIO • Drop Logic • if (Q > Limit) • Drop • else if (EARhigh > SR) • if (L-class or M-class) Drop • if (H-class) Drop with P = (EARhigh– SR) / EARhigh • else if (EARhigh+ EARmid > SR) • if (L-class) Drop • if (M-class) Drop with P = (EARhigh+ EARmid– SR) / EARmid • else if (EAR > SR) • if (L-class) Drop with P = (EAR – SR) / EARlow WPI

10. Rb-RIO Mappings • MPEG Video • I-frame packets = H-class • P-frame packets = M-class • B-frame packets = L-class • TCP • Randomly map incoming TCP packets • H-class : M-class : L-class = x : y : z WPI

11. Outline • Introduction • Approaches • Rb-RIO • Experiments • Results • Summary WPI

12. Experiments • Implement Rb-RIO in NS • General Settings • Network Packet Size = 1 KB • MPEG Frame Size (from a news clip) I, P, B = 11, 8, 2 (KB) • Rb-RIO Priority Class Mapping for TCP H : M : L = 7 : 3 : 0 • Compare Rb-RIO with RED, Drop-Tail • Using TCP, MPEG and MIX (TCP + MPEG) WPI

13. s1 r1 25Mbps, 5ms 25Mbps, 5ms s2 r2 25Mbps, 20ms n1 n2 packet_size = 1kb s59 r59 s60 r60 40 Flows FTP-TCP 20 Flows n1-n2: q_size = 100 qweight = 0.0003 RED: max_th = 60 min_th = 20 max_p = 0.1 Rb-RIO: interval = 1ms ear_k = 0.5 aggr_p = 2.5 FTP-TCP 0 10 20 30 Simulation Time (Seconds) EXP TCP: Setup WPI

14. EXP TCP: Summary • Comparing Rb-RIO with Drop-Tail and RED (well-configured) • Throughput: All compatible • Drop Rate: All compatible • Fairness: RED and Rb-RIO are compatible and fairer than Drop-Tail WPI

15. s1 r1 25Mbps, 5ms 25Mbps, 5ms s2 r2 25Mbps, 20ms n1 n2 packet_size = 1kb s59 r59 s60 r60 Responsive MPEG 40 Flows Unresponsive MPEG 20 Flows n1-n2: q_size = 100 qweight = 0.0003 RED: max_th = 60 min_th = 20 max_p = 0.1 Rb-RIO: interval = 1ms ear_k = 0.5 aggr_p = 2.5 0 10 20 30 Simulation Time (Seconds) EXP MPEG: Setup WPI

16. EXP MPEG: Pkt & Frm Statistics Responsive MPEG Unresponsive MPEG WPI

17. EXP MPEG: Decodable Frames (Responsive MPEG) WPI

18. EXP MPEG: Decodable Frames (Unresponsive MPEG) WPI

19. EXP MPEG: Fairness WPI

20. EXP MPEG: Summary • Rb-RIO improves video transmission over Drop-Tail and RED • Effective use of network bandwidth • Smoother video streams (less jitter) • Improves fairness among video streams • Same kind of streams • Different kind of streams WPI

21. s1 r1 25Mbps, 5ms 25Mbps, 5ms s2 r2 25Mbps, 20ms n1 n2 packet_size = 1kb s59 r59 20 Flows FTP-TCP s60 r60 Responsive MPEG 20 Flows n1-n2: q_size = 100 qweight = 0.0003 RED: max_th = 60 min_th = 20 max_p = 0.1 Rb-RIO: interval = 1ms ear_k = 0.5 aggr_p = 2.5 Unresponsive MPEG 20 Flows 0 10 20 30 Simulation Time (Seconds) EXP MIX: Setup WPI

22. EXP MIX: Fairness WPI

23. EXP MIX: Summary • Rb-RIO improves video transmission over Drop-Tail and RED as in EXP MPEG • Protects TCP from other flows that are unresponsive or response differently to network congestion WPI

24. Summary • Rb-RIO behaves compatibly with well-configured RED on TCP flows • Offers efficient and smoother video transmission • Improves fairness among video streams • Protects TCP using configurable TCP mapping ratio WPI

25. Future Work • Thorough evaluation of Rate-Based AQM mechanism (with TCP) • Try and evaluate Rb-RIO with other video streams (H.263+, RealVideo) • Design an AQM mechanism that can control delay for interactive multimedia streaming WPI