This open source distribution contains documentation, scripts, and other materials related to the BBR congestion control algorithm.

Quick links

• Linux TCP BBRv3 Release:
  • https://github.com/google/bbr/blob/v3/README.md
• BBR FAQ:
  • https://github.com/google/bbr/blob/master/Documentation/bbr-faq.md
• TCP BBR Quick-Start: Building and Running TCP BBR on Google Compute Engine:
  • https://github.com/google/bbr/blob/master/Documentation/bbr-quick-start.md
• Mailing list: Test results, performance evaluations, feedback, and BBR-related discussions are very welcome in the public e-mail list for BBR: https://groups.google.com/d/forum/bbr-dev

Latest BBR code from Google's BBR team

• For Linux TCP BBR:

  • https://github.com/google/bbr/blob/v3/net/ipv4/tcp_bbr.c

• For QUIC BBR:

  • https://github.com/google/quiche/blob/main/quiche/quic/core/congestion_control/bbr2_sender.cc
  • https://github.com/google/quiche/blob/main/quiche/quic/core/congestion_control/bbr2_sender.h

BBR v1 releases

• For Linux TCP BBR:

  • https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/tree/net/ipv4/tcp_bbr.c

• For QUIC BBR:

  • https://github.com/google/quiche/blob/main/quiche/quic/core/congestion_control/bbr_sender.cc
  • https://github.com/google/quiche/blob/main/quiche/quic/core/congestion_control/bbr_sender.h

BBR Internet Draft

• There is an Internet Draft specifying BBR:
  • BBR is a Congestion Control Working Group (CCWG) "working group item"
  • Target: publish an experimental RFC documenting the algorithm
  • IETF working group members are collaborating on github
    • https://github.com/ietf-wg-ccwg/draft-ietf-ccwg-bbr
    • Ideas or suggestions? Feel free to file a github issue.
    • Specific editorial suggestions? Feel free to propose a pull request.
  • BBR Internet Draft: draft-ietf-ccwg-bbr
    • https://datatracker.ietf.org/doc/draft-ietf-ccwg-bbr/

Information About BBR

• There is a blog post on the launch of BBR for Google.com, YouTube, and Google Cloud Platform
• There is an article describing BBR in the February 2017 issue of CACM (the same content is in the ACM Queue BBR article from Oct 2016).
• [YouTube] [slides] for a BBR talk at the Linux netdev 1.2 conference (Oct 2016)
• [YouTube] [slides] for a BBR talk in the ICCRG session at IETF 97 (Nov 2016)
• [YouTube] [slides] for a talk covering policers and BBR's handling of policers, in the MAPRG session at IETF 97 (Nov 2016)
• [YouTube] [slides] BBR talk at the ICCRG session at IETF 98 (Mar 2017)
• [YouTube] [slides] BBR talk at the ICCRG session at IETF 99 (Jul 2017)
• [YouTube] [slides] BBR talk at the ICCRG session at IETF 100 (Nov 2017)
• [YouTube] [slides] BBR talk at the ICCRG session at IETF 101 (Mar 2018)
• [YouTube] [slides] BBR Congestion Control Work at Google: IETF 102 Update (Jul 2018)
• [YouTube] [slides] BBR Congestion Control: IETF 102 Update: BBR Startup (Jul 2018)
• [YouTube] [slides] BBR v2: A Model-based Congestion Control - ICCRG at IETF 104 (Mar 2019)
• [YouTube] [slides] BBR v2: A Model-based Congestion Control: IETF 105 Update - ICCRG (Jul 2019)
• [YouTube] [slides] BBR v2: A Model-based Congestion Control: Performance Optimizations - IETF 106 - ICCRG (Nov 2019)
• [YouTube] BBR: A Model-based Congestion Control - High-Speed Networking Workshop (May 2020)
• [YouTube] [slides] BBR Update: 1: BBR.Swift; 2: Scalable Loss Handling - IETF 109 - ICCRG (Nov 2020)
• [YouTube] [slides] BBR Internal Deployment, Code, Draft Plans - IETF 110 - ICCRG (Mar 2021)
• [YouTube] [slides] BBRv2 Update: Internet Drafts & Deployment Inside Google - IETF 112 - ICCRG (Nov 2021)
• [YouTube] [slides] BBRv2 Update: QUIC Tweaks and Internet Deployment - IETF 112 ICCRG (Nov 2021)
• [YouTube] [slides] BBRv3: Algorithm Updates and Public Internet Deployment - IETF 117 - CCWG (Jul 2023)
• [YouTube] [slides] BBRv3: Algorithm Overview and Google's Public Internet Deployment - IETF 119 - CCWG (Mar 2024)
• [YouTube] [slides] BBRv3: Internet Draft Update: draft-cardwell-ccwg-bbr-00 - IETF 120 - CCWG (Jul 2024)

This is not an official Google product.