It is increasingly difficult for Internet congestion control mechanisms to
obtain the feedback that they need. This lack of feedback can have severe
performance implications, and it is bound to become worse. In the long run, the
problem may only be fixable by fundamentally changing the way congestion
control is done in the Internet. We substantiate this claim by looking at the
evolution of the Internet's infrastructure over the past thirty years, and by
examining the most common behavior of Internet traffic. Considering the goals
that congestion control mechanisms are intended to address, and taking into
account contextual developments in the Internet ecosystem, we arrive at
conclusions and recommendations about possible future congestion control design
directions. In particular, we argue that congestion control mechanisms should
move away from their strict "end-to-end" adherence. This change would benefit
from avoiding a "one size fits all circumstances" approach, and moving towards
a more selective set of mechanisms that will result in a better performing
Internet. We will also discuss how this future vision differs from today's use
of Performance Enhancing Proxies (PEPs).Comment: Accepted for publication in IEEE Communications Magazine, 2022 (Open
Call Article