Paper Review:
Dynamic Behavior of Slowly-Responsive Congestion Control Algorithms

Reviewer: Jie Zhou


Different classes of Internet applications demand different congestion control algorithms. To co-exist with the dominant TCP, these algorithms should be governed by the TCP-compatibility requirement. However, this requirement is based on static notion of throughput under a steady-state loss rate. How about its effeciency in practice, where most conditions are dynamic.


This paper investigates the behavior of slowly-responsive, TCP compatible congestion control algorithms under more realistic dynamic network conditions, addressing the fundamental question of whether these algorithms are safe to deploy in the public Internet.

Main Ideas

  • Slowly-responsive TCP-compatible algorithms may not always get their equitable share when network conditions change dynamically.
  • Incorporating the principle of packet conservation is crucial in dynamic settings to ensure safety.


    I give the paper a rate 3 (modest contribution), because it renders more realistic analysis of slowly-responsive congestion control algorithms in Internet, but this is not an original problem.

    The authors test SlowCC mechanism on four aspects: 1) response to a suden increase in congestion; 2) long-term bandwidth fairness; 3) transient fairness; 4) link utilization. I think it basically covers most we want to know about SlowCC's performance in dynamic setting. Besides, the experiments have been made in a single-bottleneck "dumbbell" topology with RED queue management at the bottleneck. Though simple, the model is appropriate.


  • Internet is a environment made up of dynamic conditions. It is dangerous to only study the static behavior of certain algorithm or application.