[tsvwg] L4S issue #19: Single codepoint for both low latency & resequencing tolerance

Wesley Eddy <wes@mti-systems.com> Fri, 31 July 2020 15:32 UTC

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From: Wesley Eddy <wes@mti-systems.com>
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Date: Fri, 31 Jul 2020 11:32:35 -0400
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Subject: [tsvwg] L4S issue #19: Single codepoint for both low latency & resequencing tolerance
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Hello, this email is to check with the list and see if my understanding 
is correct that this ticket should be closed:

https://trac.ietf.org/trac/tsvwg/ticket/19

The ticket was opened originally when there was a "MUST" statement about 
L4S flows being robust to reordering.  The current draft has both 
brought that down to a "SHOULD" as well as scoping it to 
reordering-prone networks, so I believe this has been addressed with the 
current text:

    o  A scalable congestion control intended for reordering-prone
       networks SHOULD detect loss by counting in time-based units, which
       is scalable, as opposed to counting in units of packets (as in the
       3 DupACK rule ofRFC 5681  <https://datatracker.ietf.org/doc/html/rfc5681>  TCP), which is not scalable (see
       Appendix A.1.7  <https://datatracker.ietf.org/doc/html/draft-ietf-tsvwg-ecn-l4s-id-10#appendix-A.1.7>  for rationale).  This requirement is scoped to
       'reordering-prone networks' in order to exclude congestion
       controls that are solely used in controlled environments where the
       network introduces hardly any reordering.

Please let me know in the next week if I've got this wrong and the 
ticket should remain open.