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LEDBAT++: Congestion Control for Background Traffic

Document Type Expired Internet-Draft (iccrg RG)
Expired & archived
Authors Praveen Balasubramanian , Osman Ertugay , Daniel Havey
Last updated 2021-03-08 (Latest revision 2020-08-25)
Replaces draft-balasubramanian-iccrg-ledbatplusplus
RFC stream Internet Research Task Force (IRTF)
Intended RFC status (None)
Additional resources Mailing list discussion
Stream IRTF state (None)
Consensus boilerplate Unknown
Document shepherd (None)
IESG IESG state Expired
Telechat date (None)
Responsible AD (None)
Send notices to (None)

This Internet-Draft is no longer active. A copy of the expired Internet-Draft is available in these formats:


This informational memo describes LEDBAT++, a set of enhancements to the LEDBAT (Low Extra Delay Background Transport) congestion control algorithm for background traffic. The LEDBAT congestion control algorithm has several shortcomings that prevent it from working effectively in practice. LEDBAT++ extends LEDBAT by adding a set of improvements, including reduced congestion window gain, modified slow-start, multiplicative decrease and periodic slowdowns. This set of improvement mitigates the known issues with the LEDBAT algorithm, such as latency drift, latecomer advantage and inter-LEDBAT fairness. LEDBAT++ has been implemented as a TCP congestion control algorithm in the Windows operating system. LEDBAT++ has been deployed in production at scale on a variety of networks and been experimentally verified to achieve the original stated goals of LEDBAT.


Praveen Balasubramanian
Osman Ertugay
Daniel Havey

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)