Paper review : Congestion Avoidance and Control (Jac88)

• Goal
  To implement congestion avoidance and control for TCP.

• Contribution
  The authors investigate the transport protocol implementations, analysis the reasons of why packet conservation may fail, and propose several algorithms for 4BSD TCP, which was originally mis-behaving and is tuned to work better under abysmal network conditions.

• Main ideas
  • Much of the cause of the congestion problems lies in transport protocol implementations instead of the protocols themselves.
  • 4.3BSD TCP was mis-behaving and it could be tuned to work better when a group of algorithms applied.

• Evaluation
  • Significance rating: 4
    This is the first attempt on implementing congestion avoidance and control for TCP. The authors also provide different algorithms to tackle different problems. (4)

  • Convincing rating
    The authors investigate the deficit of the primitive implementation of the TCP protocols, design several algorithms to tackle the different failures of packet conservation, analysis the results mathematically, and provide the data of the experiments to show the good performance of the algorithms on dealing with congested conditions on the Internet.

  • Limitation
    As the authors mentioned, the paper only provides the solutions on the transport endpoints, whereas the gateway side of congestion control was left for future investigation. Moreover, congestion detection is another important problem besides congestion avoidance and control.

• Conclusion
  Protocols themselves cannot always avoid network congestion problems, the investigations of the implementation aspect can generate algorithms that improve the performance of network traffic greatly.

  9/24/01