Re: [tcpm] I-D Action: draft-ietf-tcpm-prr-rfc6937bis-03.txt

Hi,

I have one minor observations.

In Section 6 where the algorithm is described, while the document does
state to initialize the variable prr_delivered to zero at the beginning
of recovery, it may be clearer to point out that this explicitly
excludes any Limited Transmit period just prior of entering Fast Recovery.

While this becomes clear when observing PRR working, I had been using
sacked_bytes for initializing prr_delivered (which naturally will
already be inflated by however many segments were sent during limited
transmit).

Suggest to raise awareness of this potential implementation oversight by
explicitly pointing it out.

Other than this, I wanted to mention that code to do PRR according to
6937bis should be ready soon in fbsd.

Best regards,
   Richard

Am 27.03.2023 um 07:32 schrieb internet-drafts@ietf.org:
>
> A New Internet-Draft is available from the on-line Internet-Drafts
> directories. This Internet-Draft is a work item of the TCP Maintenance and
> Minor Extensions (TCPM) WG of the IETF.
>
>     Title           : Proportional Rate Reduction for TCP
>     Authors         : Matt Mathis
>                       Nandita Dukkipati
>                       Yuchung Cheng
>     Filename        : draft-ietf-tcpm-prr-rfc6937bis-03.txt
>     Pages           : 18
>     Date            : 2023-03-26
>
> Abstract:
>     This document updates the experimental Proportional Rate Reduction
>     (PRR) algorithm, described RFC 6937, to standards track.  PRR
>     potentially replaces the Fast Recovery to regulate the amount of data
>     sent by TCP or other transport protocol during loss recovery.  PRR
>     accurately regulates the actual flight size through recovery such
>     that at the end of recovery it will be as close as possible to the
>     slow start threshold (ssthresh), as determined by the congestion
>     control algorithm.
>
> The IETF datatracker status page for this Internet-Draft is:
> https://datatracker.ietf.org/doc/draft-ietf-tcpm-prr-rfc6937bis/
>
> There is also an HTML version available at:
> https://www.ietf.org/archive/id/draft-ietf-tcpm-prr-rfc6937bis-03.html
>
> A diff from the previous version is available at:
> https://author-tools.ietf.org/iddiff?url2=draft-ietf-tcpm-prr-rfc6937bis-03
>
> Internet-Drafts are also available by rsync at rsync.ietf.org::internet-drafts
>
>
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