[tcpPrague] Treatment of ECT(1) pre L4S

Dave Dolson <ddolson@sandvine.com> Fri, 22 July 2016 11:01 UTC

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From: Dave Dolson <ddolson@sandvine.com>
To: TCP Prague List <tcpPrague@ietf.org>
Thread-Topic: Treatment of ECT(1) pre L4S
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Date: Fri, 22 Jul 2016 11:01:06 +0000
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Subject: [tcpPrague] Treatment of ECT(1) pre L4S
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If an operator were to deploy ECN today, pre L4S, what should be the treatment of ECT(1)?

I believe, from a discussion with Koen, that the safest approach is for a pre-L4S implementation to signal congestion to ECT(1) by dropping. If ECT(1) were treated the same as ECT(0) then new experimental TCP-Prague flows would out-compete any ECT(0) traffic.

Is this agreed? If so, should it be recommended somewhere?

Note that I got mixed answers on this from other IETF folks, so I think it is worth sorting out.