Paper Review:
Analysis and Design of an Adaptive Virtual Queue (AVQ) Algorithm for Active Queue Management

Reviewer: Jie Zhou

Problem

In the modern day Internet, links play an active role in congestion control and avoidance, so as to achieve the effeciency and fairness among flows. Against this background, designing Adaptive Queue Management (AQM) schemes have been a hot research area in the Internet community. One important question is how fast should one adapt while maintaining the stability of the system?

Contribution

The paper presents an easily implementable AQM scheme, called Adaptive Virtual Queue (AVQ), and provides a simple rule to design its parameters.

Main Ideas

  • AVQ is primarily a rate-based marking algorithm, which regulate utilization.
  • Compared with other AQM schemes, e.g. RED, AVQ achieves high utilization and low packet loss, and responses quickly to changing network conditions.

    Critique

    The proposed algorithm in this paper tries to regulate the utilization instead of queue length that traditional AQM algorithms focus on. In my view, this approach is more desirable because the traditional ones will lead to the situation where excessively large queue lengths persist over long periods of time. Besides, this paper provides insight into the problem of TCP/AQM model's stability. Based on these reasons, I rate the paper at 4 (significant contribution).

    The paper includes thorough and sound theoretical analysis and sufficient experiment data. I feel it is very convincing.

    Lession

    The stability of a linear delay-differntial equation can be analyzed using its characteristic equation.