Paper review: < Analysis of the Increase and Decrease Algorithms for Congestion Avoidance in Computer Networks [CJ89] >

Reviewer: <Ryan Gehl>

  1. State the problem the paper is trying to solve.
  2. This paper concentrates on a detailed analysis of the increase/decrease algorithms for dealing with the problem of network congestion.

  3. State the main contribution of the paper: solving a new problem, proposing a new algorithm, or presenting a new evaluation (analysis). If a new problem, why was the problem important? Is the problem still important today? Will the problem be important tomorrow?  If a new algorithm or new evaluation (analysis), what are the improvements over previous algorithms or evaluations? How do they come up with the new algorithm or evaluation? 
  4. The main contribution of this paper is to abstractly characterize the wide class of increase/decrease algorithms and compare them using several different performance metrics.

  5. Summarize the (at most) 3 key main ideas (each in 1 sentence.) 
  6. (1) Congestion avoidance and congestion control are two different things. Congestion avoidance attemnpts to keep the network from congesting by "operating at the knee" whereas congestion control shemes help improve performance after congestion has occurred.
    (2) The criteria for selecting controls are efficiency, fairness, distributedness, and convergence. (3) What are all the possible solutions that converge to efficient and fair states? How do we compare those controls that converge.

  7. Critique the main contribution
  8. What lessons should researchers and builders take away from this work. What (if any) questions does this work leave open?

A simple additive increase and multiplicative decrease algorithm satisfiees the sufficient conditions for convergence to an efficient and fair state regardless of the starting state of the network.