1 / 22

Dynamic-CBT and ChIPS: Enhancing Multimedia Router Performance on the Internet

This study, conducted by Jae Chung and Mark Claypool at Worcester Polytechnic Institute, investigates Dynamic-CBT (Class-Based Threshold) and ChIPS (Cut-In Packet Scheduling) as advanced techniques for managing router performance in multimedia applications. Traditional TCP, while reliable, often falls short for interactive multimedia due to its delay and retransmission issues. Our findings highlight how the integration of D-CBT and ChIPS can significantly improve congestion control, reduce jitter, and enhance fairness among different traffic flows. This research proposes a responsive multimedia architecture that addresses key challenges in packet scheduling and resource reservation.

prentice
Download Presentation

Dynamic-CBT and ChIPS: Enhancing Multimedia Router Performance on the Internet

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Dynamic-CBT and ChIPS – Jae Chung and Mark Claypool Router Support for Improved Multimedia Performance on the Internet Computer Science Department Worcester Polytechnic Institute Worcester, Massachusetts, USA http://perform.wpi.edu/

  2. The Internet and Multimedia • Internet routers are best effort • No timing constraints • Packet loss, which indicates congestion • TCP • Completely reliable delivery through retransmission • Respond to loss as congestion • But … TCP often unsuitable for interactive multimedia • Full reliability not needed • Window-based rate fluctuations

  3. Multimedia Using TCP

  4. Multimedia Using UDP

  5. Multimedia on the Internet • Multimedia often uses UDP • Avoid delay and jitter from retransmission • Rate-based • Unresponsive! • Router queue management goals • Congestion Control • Fairness • Reduce Jitter

  6. Resource Reservation Active Queue Mgmt ... CBQ RED ... (Floyd, Jacobson ‘95) (Floyd, Jacobson ‘93) Class-Based Threshold (CBT) (Parris, Jeffay, Smith ‘99) Router Queue Management Bursty Loss Unfairness Drop Tail (FIFO)

  7. Outline • Introduction  • CBT  • D-CBT • ChIPS • Conclusion

  8. CBT Design

  9. FRED (Lin, Morris ‘97) Dynamic-CBT Router Queue Management ChIPS Drop Tail (FIFO) Resource Reservation Active Queue Mgmt ... CBQ RED ... (Floyd, Jacobson ‘95) (Floyd, Jacobson ‘93) Class-Based Threshold (CBT) (Parris, Jeffay, Smith ‘99)

  10. D-CBT Design Responsive MM Enable Thrsh

  11. Evaluation in NS • Developed responsive multimedia application (for tagged UDP class) • AIMD Media Scaling (5 discrete rates) • “MPEG-1 like” transmission rates • Implemented and validated CBT • Implemented D-CBT and measured congestion time fairness • RED vs. CBT vs. D-CBT

  12. 25Mbps, 5ms 25Mbps, 5ms 25 FTP-TCP s1 r2 25Mbps, 20ms 10 MM-UDP s2 r2 n1 n2 s66 r66 n1-n2: q_size = 60 RED: max_th = 15 min_th = 5 qweight = 0.002 max_prb = 0.1 CBT: mmu_th = 2.9 udp_th = 0.6 2 CBR-UDP (5Mbps each) s67 r67 30 FTP-TCP 0 10 20 30 Second Simulation (RED, CBT, D-CBT)

  13. Fairness: RED

  14. Fairness: CBT

  15. Fairness: D-CBT

  16. Outline • Introduction  • CBT and D-CBT  • Design  • Evaluation  • ChIPS  • Design • Evaluation • Conclusion

  17. Cut-In Packet Scheduling (ChIPS) Design

  18. ChIPS Evaluation - Jitter

  19. TCP Packets Delivered TCP Packet Drop Rate TCP Throughput D-CBT 66,648 pkts 4.46 % 17,773 Kbps D-CBT w/ ChIPS 66,386 pkts 4.44 % 17,703 Kbps ChIPS Evaluation - Fairness

  20. Conclusion • D-CBT • Protect responsive flows from unresponsive • Class-based consideration • Adaptive to mix of flows • ChIPS • Reduce multimedia jitter during congestion

  21. Future Work • Active Flow Counting (Overhead) • For every incoming packet, update flow info • Hash Table - O(1) • Every ms, delete old flows • Hash Table - O(n) • Measure Overhead • Processing Time and Memory Usage

  22. Future Work • How many different classes are needed? • Example • 1 class is RED • 1 class per flow is FRED • Overhead per class • Effects of D-CBT and ChIPS on Perceptual Quality

More Related