  Congestion control algorithms are crucial in achieving high utilization while
preventing overloading the network. Over the years, many different congestion
control algorithms have been developed, each trying to improve in specific
situations. However, their interactions and co-existence has, to date, not been
thoroughly evaluated, which is the focus of this paper. Through head-to-head
comparisons of representatives from loss-based, delay-based and hybrid types of
congestion control algorithms, we reveal that fairness in resources claimed is
often not attained, especially when flows sharing a link have different RTTs.
