Uber’s use of QUIC to improve latency over cellular networks

Unfortunately, the HTTP/2 stack fares poorly in dynamic, lossy wireless networks, and we learned that poor performance can often be traced directly to Transmission Control Protocol (TCP) implementations buried in OS kernels. In this article, we share our experiences optimizing TCP performance for Uber’s apps by moving to a network stack that supports the QUIC protocol. This can be attributed to the inefficient computation of RTOs, TCP’s inability to react quickly to loss of last few packets in a window (tail loss), and inefficiencies in the congestion control algorithm, which does not differentiate between wireless losses and losses due to network congestion.

Source: eng.uber.com