better-behaved multimedia networking
DESCRIPTION
Better-Behaved Multimedia Networking. Keith Barber Jason Ingalsbe Joel Thibault Prof. Mark Claypool (Advisor) April 19, 2001. Issues with Multimedia Traffic. Basic Internet protocols inappropriate for multimedia TCP does not provide smooth transmission UDP takes up too much bandwidth - PowerPoint PPT PresentationTRANSCRIPT
Better-Behaved Multimedia Networking
Keith Barber
Jason Ingalsbe
Joel Thibault
Prof. Mark Claypool (Advisor)
April 19, 2001
Issues with Multimedia Traffic
• Basic Internet protocols inappropriate for multimedia– TCP does not provide smooth transmission– UDP takes up too much bandwidth
• Multimedia protocols must be TCP-friendly
Existing Alternatives
• TCP-Friendly Rate Control (TFRC)
• TCP Emulation At Receivers (TEAR)
• MM-Flow
Re-Engineering MM-Flow
• Location of flow control logic– “True” application and transport layers– Receiver decides whether scale value should
change– Sender converts scale values to transmission
rate
• Number of scale values• Weighted average scale
Evaluation Techniques
• Simulation Scenarios– Standard Bottleneck Layout– Standard Delay Layout– Standard Fragile Layout
Standard Bottleneck Layout
Standard Delay Layout
Standard Fragile Layout
Effects of Re-Engineering MM-Flow
• Responsiveness to Congestion
• Fair Share of Bandwidth
• Relative Smoothness
MM-App-Old vs. TCP
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Percent Utilization
TCP MM-App-Old Total
MM-App-Old Average Utilization = 66.0% TCP Average Utilizaton = 32.7%
MM-App-New vs. TCP
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Percent Utilization
TCP MM-App-New Total
MM-App-New Average Utilization = 51.8% TCP Average Utilizaton = 44.5%
Further Evaluation of MM-App-New
• Packet Size
• Number of Scale Values
• Delay
• Fragile Flows
• Weighted Scale Values
TCP-Friendly Flows
• Possible definitions:– Flow uses fair share of bandwidth– Flow responds to congestion– Flow transmission rate less than or equal to
TCP flow transmission rate
• Quantitative measurement is desired
TCP-Friendly Equation
• Implications and Assumptions:– Packet Drop Rate– Measurement Interval Size
pR
BT
*
*3/25.1
TCP-Friendly Results (1 sec.)
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Time (sec)
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bp
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Actual Bandwidth
TCP-Friendly Bandwidth
TCP-Friendly Results (3 sec.)
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Time (sec)
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Actual Bandwidth
TCP-Friendly Bandwidth
TCP-Friendliness of MM-App-New
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Time (sec)
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Fair Bandwidth
TCP-Friendliness of TFRC
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Time (sec)
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Actual Bandwidth
TCP-Friendly Bandwidth
Fair Bandwidth
Multi-Protocol Layout
Multi-Protocol Env. (TCP)
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Time (sec)
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nd
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th (
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Actual Bandwidth
TCP-Friendly Bandwidth
Fair Bandwidth
Multi-Protocol Env. (TFRC)
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Time (sec)
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Actual Bandwidth
TCP-Friendly Bandwidth
Fair Bandwidth
Multi-Protocol Env. (MM-App-New)
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Time (sec)
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Actual Bandwidth
TCP-Friendly Bandwidth
Fair Bandwidth
Conclusion and Future Work
• MM-Flow is an improvement over original
• Areas for future research:– Increase transmission rate quickly at startup– Decrease fluctuation in transmission rate– Continue examination of TCP-Friendliness
Questions?
http://www.wpi.edu/~jmi725/mqp
http://perform.wpi.edu