1. Jingyuan Wang, Jiangtao Wen, Jun Zhang and Yuxing Han
Tsinghua National Laboratory for Information Science and Technology

2.  Introduction
 Background and Motivation
 The TCP-FIT Algorithm
 Experimental Results
 Conclusion

3.  TCP
◦ The Transmission Control Protocol
 TCP Reno/ TCP New Reno
◦ Pros
 Reliable
 Sequential
◦ Cons
 Wireless network
 high Bandwidth Delay Product (BDP)

4.  Recent development
◦ Wireless
 TCP Westwood
 TCP Veno
◦ BDP
 TCP Compound
 TCP CUBIC
 FAST TCP
 TCP-FIT
◦ Inspired by parallel TCP

5.  Introduction
 Background and Motivation
 The TCP-FIT Algorithm
 Experimental Results
 Conclusion

6.  What is a Congestion Algorithm?
 Classification
◦ Loss-based
◦ Delay-based
◦ Hybrid

7.  Loss-Based
◦ TCP Reno, TCP CUBIC
◦ TCP BIC , High Speed TCP
 Definition
 Assumption
◦ Constraints
 In wireless scenarios
 In BDP scenarios

8.  Delay-Based
◦ TCP Vegas and FAST TCP
 Definition
 Assumption
◦ Queuing delay = RTT – Propagation delay.
◦ Pros
 Resilient -> good
◦ Cons
 bandwidth starvation

9.  Hybrid TCP
◦ Veno, TCP Westwood, TCP Illinois, H-TCP and
Fusion TCP
◦ Compound TCP
 Cons
◦ Poor in BDP-wireless-hybrid scenarios

10.  TCP-FIT
◦ Parallel TCP
◦ E.g. GridFTP and E-MulTCP
◦ Pros:
 Utilization
 Good in wireless and BDP
◦ Cons:
 Compatibility
 Fairness

11.  Introduction
 Background and Motivation
 The TCP-FIT Algorithm
 Experimental Results
 Conclusion

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19.  Introduction
 Background and Motivation
 The TCP-FIT Algorithm
 Experimental Results
 Conclusion

20.  BDP Scenarios

21.  Wireless Scenarios

22.  Inter-fairness

23.  RTT-fairness

24.  Cons:
◦ a low speed ADSL network with large bandwidth
variations
◦ Due to simplistic model of bandwidth estimation
compared with FAST.

25. Thank
you