tcp bbr v3(一)
目前google 发布了tcp bbrv2+fixbug===tcp bbrv3
目前说是 BBRv3 的数据包重传率降低了 12%,延迟也略有改善
Impact of BBRv3 vs BBRv1 on Google.com and YouTube TCP public Internet traffic:
○ Lower retransmit rate (12% reduction)
○ Slight latency improvement (0.2% reduction) for:
■ Google.com web search
■ Starting YouTube video playback
○ Latency wins seem to be from lower loss rate (less/faster loss recovery)
- https://github.com/google/bbr/blob/v3/README.md
- https://datatracker.ietf.org/meeting/117/materials/slides-117-ccwg-bbrv3-algorithm-bug-fixes-and-public-internet-deployment-00
New: a version increment for BBR, from v2 to v3
○ Recent bug fixes change the bandwidth/fairness convergence properties of BBR ○ So most test results for BBRv2 will not apply to BBRv3
○ So we are incrementing the version number for BBR from v2 to v3
● A summary of BBR versions:
○ BBRv1: [obsolete/deprecated]
■ Bandwidth, RTT as signals primary signals; loss used over short time scales
○ BBRv2: [obsolete/deprecated]
■ BBRv1 + using ECN, loss as signals (with bugs mentioned previously at IETF)
○ BBRv3:
■ BBRv2 + bug fixes and performance tuning
○ BBR.Swift: [discussed at IETF 109: slide link]
■ BBRv3 + using network_RTT (excluding receiver delay) as primary CC signal