  TCP and its variants have suffered from surprisingly poor performance for
decades. We argue the TCP family has little hope to achieve consistent high
performance due to a fundamental architectural deficiency: hardwiring
packet-level events to control responses without understanding the real
performance result of its actions. We propose Performance-oriented Congestion
Control (PCC), a new congestion control architecture in which each sender
continuously observes the connection between its actions and empirically
experienced performance, enabling it to consistently adopt actions that result
in high performance. We prove that PCC converges to a stable and fair
equilibrium. Across many real-world and challenging environments, PCC shows
consistent and often 10x performance improvement, with better fairness and
stability than TCP. PCC requires no router hardware support or new packet
format.
