Better-Behaved Multimedia Networking.ppt

1、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 protocol

2、s 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 tra

3、nsmission 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 t

4、o Congestion Fair Share of Bandwidth Relative Smoothness,MM-App-Old vs. TCP,MM-App-New vs. TCP,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 con

5、gestion 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,TCP-Friendly Results (1 sec.),TCP-Friendly Results (3 sec.),TCP-Friendliness of MM-App-Ne

6、w,TCP-Friendliness of TFRC,Multi-Protocol Layout,Multi-Protocol Env. (TCP),Multi-Protocol Env. (TFRC),Multi-Protocol Env. (MM-App-New),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,