BBR Fairness Evaluation Using NS-3

TL;DR

While BBR improves performance over loss-based methods in single flows, unfairness issues emerge with competing BBR and BBR/Cubic flows.

Abstract

This paper evaluates the fairness of BBR congestion control using NS-3 simulator. While BBR improves performance over loss-based methods in single flows, unfairness issues emerge with competing BBR and BBR/Cubic flows. Unfairness correlates with factors like round-trip time and buffer size. The core reason is the lack of responding mechanisms for the flows to converge on fair bandwidth share.

Figures (6)

• Figure 1: NS-3 dumbbell visualization.
• Figure 2: Single flow experiment at default configuration
• Figure 3: Synchronization behavior between two BBR flows
• Figure 4: Overestimate bandwidth behavior for three BBR flows at default configuration
• Figure 5: Throughput measurement between BBR flow and Cubic flow