Early BBRv3 Measurements Across Saturated Transpacific Transit

BBRv3 introduces significant refinements over v1 and v2, notably incorporating explicit loss response algorithms to address the long-standing complaint that BBRv1 was overly aggressive when sharing shallow-buffer bottlenecks with Reno or Cubic flows.

Over a three-week continuous test across a dedicated 10Gbps cross-connect between our West Coast and East Asia PoPs, BBRv3 reduced flow retransmissions by 34% compared to BBRv1 under induced 1% packet loss, while maintaining 98.4% of maximum throughput. Crucially, in mixed-flow tests against Cubic, BBRv3 settled at a 52/48 bandwidth split, indicating that inter-protocol fairness has substantially matured.