Subject: [tcpm] Last Call: <draft-ietf-tcpm-proportional-rate-reduction-04.txt> (Proportional Rate Reduction for TCP) to Experimental RFC

From: The IESG <[email-masked]>
Date: Tue, 12 Feb 2013 06:37:31 -0800

The IESG has received a request from the TCP Maintenance and Minor
Extensions WG (tcpm) to consider the following document:
- 'Proportional Rate Reduction for TCP'
  <draft-ietf-tcpm-proportional-rate-reduction-04.txt> as Experimental
RFC

The IESG plans to make a decision in the next few weeks, and solicits
final comments on this action. Please send substantive comments to the
[email-masked] mailing lists by 2013-02-26. Exceptionally, comments may be
sent to [email-masked] instead. In either case, please retain the
beginning of the Subject line to allow automated sorting.

Abstract

   This document describes an experimental algorithm, Proportional Rate
   Reduction (PPR) to improve the accuracy of the amount of data sent by
   TCP during loss recovery.  Standard Congestion Control requires that
   TCP and other protocols reduce their congestion window in response to
   losses.  This window reduction naturally occurs in the same round
   trip as the data retransmissions to repair the losses, and is
   implemented by choosing not to transmit any data in response to some
   ACKs arriving from the receiver.  Two widely deployed algorithms are
   used to implement this window reduction: Fast Recovery and Rate
   Halving.  Both algorithms are needlessly fragile under a number of
   conditions, particularly when there is a burst of losses such that
   the number of ACKs returning to the sender is small.  Proportional
   Rate Reduction minimizes these excess window adjustments such that at
   the end of recovery the actual window size will be as close as
   possible to ssthresh, the window size determined by the congestion
   control algorithm.  It is patterned after Rate Halving, but using the
   fraction that is appropriate for target window chosen by the
   congestion control algorithm.

The file can be obtained via
http://datatracker.ietf.org/doc/draft-ietf-tcpm-proportional-rate-reduction/

IESG discussion can be tracked via
http://datatracker.ietf.org/doc/draft-ietf-tcpm-proportional-rate-reduction/ballot/

No IPR declarations have been submitted directly on this I-D.