# An Empirical View on Content Provider Fairness

## TL;DR

This paper empirically investigates whether current Internet traffic from content providers adheres to fairness principles, revealing that some algorithms cause asymmetry but can be mitigated by active queue management techniques.

## Contribution

It provides an empirical analysis of fairness in real-world traffic from major content providers and evaluates the impact of different congestion control algorithms and queue management.

## Key findings

- Some congestion control algorithms cause unfair bandwidth distribution.
- Active queue management like FQ_CoDel can reduce unfairness.
- Content provider traffic shows significant asymmetry under certain conditions.

## Abstract

Congestion control is an indispensable component of transport protocols to prevent congestion collapse. As such, it distributes the available bandwidth among all competing flows, ideally in a fair manner. However, there exists a constantly evolving set of congestion control algorithms, each addressing different performance needs and providing the potential for custom parametrizations. In particular, content providers such as CDNs are known to tune TCP stacks for performance gains. In this paper, we thus empirically investigate if current Internet traffic generated by content providers still adheres to the conventional understanding of fairness. Our study compares fairness properties of testbed hosts to actual traffic of six major content providers subject to different bandwidths, RTTs, queue sizes, and queueing disciplines in a home-user setting. We find that some employed congestion control algorithms lead to significantly asymmetric bandwidth shares, however, AQMs such as FQ_CoDel are able to alleviate such unfairness.