Internet engineering, science, and public policy communities have significant interest in understanding the extent and scope of, as well as potential consumer harm induced by, persistent interdomain congestion on the Internet. In recent work, we developed and implemented a lightweight active...

This paper discusses the evolution of the congestion controls that govern all Internet traffic. In particular we chronicle and discuss the implications of the fact that the most significant "congestion signals" are increasingly coming from network operators, not the TCP stack. Providers now...