Re: [tsvwg] Review comments on a careful read of the L4S ID (#1: ABE)

["Black, David" <[e-mail]>]

Bob,

Let's see if we can come up with an intermediate approach that conveys useful info to the reader about ABE without endorsing it as an IETF standard.

Suggestion: No text changes for 1 and 22 (for 22, I agree that ABE does not affect marking), just add a sentence for 6 in the first paragraph of the Introduction that explains what ABE is/does and that ABE is an experiment.  No need to mention ABE again in the body of the draft (there's one mention in Appendix B.1).

Will that work?

Thanks, --David

From: tsvwg <[e-mail]> On Behalf Of Bob Briscoe
Sent: Thursday, May 13, 2021 2:04 PM
To: Gorry Fairhurst
Cc: [e-mail]
Subject: Re: [tsvwg] Review comments on a careful read of the L4S ID (#1: ABE)


[EXTERNAL EMAIL]
See [BB]...
On 06/05/2021 07:52, Gorry Fairhurst wrote:
=================================================================
1. Abstract needs to be corrected to accommodate ABE (RFC 8511).

Abstract text says:
   “ 'Classic' ECN marking is required to be
   equivalent to a drop, both when applied in the network and when
   responded to by a transport.”

⁃           That’s no longer completely correct in light of ABE (RFC 8511), although the strong connection between this marking and reaction to drops is still the case.  Perhaps: ‘Classic’ ECN marking is an enhancement to drop-based congestion control, both when applied …

=================================================================
6. Add text to acknowledge ABE (RFC 8511)

This text:
     “RFC 3168 required an ECN mark to be equivalent to a drop, both when applied in the
     network and when responded to by a transport.”

⁃            ABE (RFC 8511) has already modified that drop equivalence.  Revise this text accordingly.

=================================================================
22. Update to include ABE (RFC 8511)

This text:
     “   Note that, contrary to RFC 3168, a Dual Queue Coupled AQM
   implementing the L4S and Classic treatments does not mark an ECT(1)
   packet under the same conditions that it would have dropped a Not-ECT
   packet, as allowed by [RFC8311], which updates RFC 3168.  However, if
   it marks ECT(0) packets, it does so under the same conditions that it
   would have dropped a Not-ECT packet.”

⁃            ABE (RFC 8511) has modified that drop equivalence.  Revise this text accordingly.

=================================================================

[BB] The quotes from the draft above refer to what the standards track [RFC3168] says, not RFC8311 experiments like ABE. I don't think it will be appropriate for this draft to specifically call out ABE as if it is now accepted IETF practice. That opens us to more controversy and delay if someone disagrees with the ABE experiment.

The quote in #22 is purely about marking in the network, which ABE doesn't change, so it's definitely not appropriate to cite ABE there.

The draft does refer to RFC 8511 from an informative appendix, which I think is appropriate.

Proposed resolution: No text changes.


Bob


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Bob Briscoe                               http://bobbriscoe.net/ [bobbriscoe.net]<https://urldefense.com/v3/__http:/bobbriscoe.net/__;!!LpKI!zfPbqwU20-zdSS8IyP0GZ48zVTkiYuVPeCEerb_tyGCe-JXJAVzENUM6PA-5RaXE$>