Analysis and Simulation of a Fair Queueing Algorithm

Summary

This paper presents an algorithm that emulates bit-by-bit round robin to ensure fairness for multiple flows in the case of congestion. The authors observe that the standard first-come-first-serve algorithms have a number of problems that make them "unfair." For example, a "fire hose" sender that ignores congestion signals (e.g. dropped packets) can get a disproportionate fraction of the bandwidth.

There two main design requirements the authors follow:

1. Fairness - ill-behaved senders get no more than their fair share of bandwidth
2. Delay control - ability to control delay independent of bandwidth

The authors propose a new fair queueing algorithm. They first decide to do allocation based on conversations, e.g. source-destination pairs. To ensure fairness the algorithm emulates bit-by-bit round robin of packets from each conversation. To implement this they send packets by earliest finishing time.

Thoughts

This paper presents a good idea for improving fairness in networks. I wonder why this technique is not currently widely used?