From: Yuchung Cheng <ych...@google.com> Date: Thu, 12 Jan 2017 22:11:29 -0800
> The patch set enables RACK loss detection (draft-ietf-tcpm-rack-01) > to trigger fast recovery with a reordering timer. > > Previously RACK has been running in auxiliary mode where it is > used to detect packet losses once the recovery has triggered by > other algorithms (e.g., FACK). By inspecting packet timestamps, > RACK can start ACK-driven repairs timely. A few similar heuristics > are no longer needed and are either removed or disabled to reduce > the complexity of the Linux TCP loss recovery engine: > > 1. FACK (Forward Acknowledgement) > 2. Early Retransmit (RFC5827) > 3. thin_dupack (fast recovery on single DUPACK for thin-streams) > 4. NCR (Non-Congestion Robustness RFC4653) (RFC4653) > 5. Forward Retransmit > > After this change, Linux's loss recovery algorithms consist of > 1. Conventional DUPACK threshold approach (RFC6675) > 2. RACK and Tail Loss Probe (draft-ietf-tcpm-rack-01) > 3. RTO plus F-RTO extension (RFC5682) > > The patch set has been tested on Google servers extensively and > presented in several IETF meetings. The data suggests that RACK > successfully improves recovery performance: > https://www.ietf.org/proceedings/97/slides/slides-97-tcpm-draft-ietf-tcpm-rack-01.pdf > https://www.ietf.org/proceedings/96/slides/slides-96-tcpm-3.pdf Series applied, thanks for all of your hard work.
