Re: [tsvwg] path forward on L4S issue #16

Jonathan Morton <> Tue, 09 June 2020 15:01 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id 067533A07DC for <>; Tue, 9 Jun 2020 08:01:21 -0700 (PDT)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -1.848
X-Spam-Status: No, score=-1.848 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: (amavisd-new); dkim=pass (2048-bit key)
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id H2jKMLmsh7tn for <>; Tue, 9 Jun 2020 08:01:19 -0700 (PDT)
Received: from ( [IPv6:2a00:1450:4864:20::22b]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by (Postfix) with ESMTPS id 828463A07D0 for <>; Tue, 9 Jun 2020 08:01:19 -0700 (PDT)
Received: by with SMTP id 9so15815569ljv.5 for <>; Tue, 09 Jun 2020 08:01:19 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20161025; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=upU01WBHeZrz1eXyVCL+SlQ2qbbDOGYTPo6FcWtY9nQ=; b=cmnp0Kuyebu14/wFB32JB7/bxPa4Yx4O+4XJag/khgFKAo4J4sXsOp5GIVIybUGwDg TXDOSAuT94jBi5xm4SeyNE4xHS/t46y1Cz/qxZdk+SiY7c06PWSvXQ30cNJrKUDrCrwd NUxFi0YIYO3H5Nrn/VvARy91g6suPZJ2UlEF7JdOV2eJVjMwiYB38XImwMsz81bn+upZ k77eo6MUeO4w+PYM1rZboAwfyBKmGhZXr+AizVtJFyniCcXrz2okbS4FcSWVCR0KivTC OKDRVe3/SPHxoGZP2qA8vtb2kzQaLxzPwHWWEA/zpX8336sSPX8jvknJP4ksxXFlMf7z GDDw==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20161025; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=upU01WBHeZrz1eXyVCL+SlQ2qbbDOGYTPo6FcWtY9nQ=; b=Fa2AsBtchYBorknNRqJ/ITZmTqveL9jtwjVWvaPUV4lkuiCM+tZMfB/7bymhHAvyai jrhGacNSfWfin0Z/X3jU8/6BQl0bQDBhgHTs5UCwjh+qOOz8xtjLpo2gEES0UIHblZvp vIl5fzSkqfcBfMpO/0CvwYTeRkrEQfas+dsvaoxX+eh4jyCdAfc2ccOesDzjgk+jiH54 D+VqjXA1d2+mZmsPigqoUnTPT4jUaCFcPyT5YfiBlVagKY0jLBj1CvNK/FUch2UX9Z/t qW5vf1owRp9ZKLuMVuf/bNP6WbyyQNWt4wwrceZs33JjyytmMt0YYkbQ0MtppMHNpCjl v/NA==
X-Gm-Message-State: AOAM531wrolBbwV0IdQGYjAGgCtG6G0E6lrpGKjw27zuwbeMzZ1RUaUy U6p/OJoqPhIUGlJnpLykwNc=
X-Google-Smtp-Source: ABdhPJw9wgyqlohOAb8DRyo3fgZmf34h19tYw2xirjhlH7mBQGt858LzL5veD2GkHdFM0epdNoPlow==
X-Received: by 2002:a2e:8e82:: with SMTP id z2mr3565378ljk.71.1591714876770; Tue, 09 Jun 2020 08:01:16 -0700 (PDT)
Received: from jonathartonsmbp.lan ( []) by with ESMTPSA id p15sm4374475ljn.53.2020. (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 09 Jun 2020 08:01:14 -0700 (PDT)
Content-Type: text/plain; charset=us-ascii
Mime-Version: 1.0 (Mac OS X Mail 11.5 \(3445.9.5\))
From: Jonathan Morton <>
In-Reply-To: <>
Date: Tue, 9 Jun 2020 18:01:12 +0300
Cc: Sebastian Moeller <>, "" <>
Content-Transfer-Encoding: quoted-printable
Message-Id: <>
References: <> <> <> <> <>
To: Ingemar Johansson S <>
X-Mailer: Apple Mail (2.3445.9.5)
Archived-At: <>
Subject: Re: [tsvwg] path forward on L4S issue #16
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Transport Area Working Group <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Tue, 09 Jun 2020 15:01:21 -0000

> On 9 Jun, 2020, at 5:43 pm, Ingemar Johansson S <> wrote:
> Why don't you run the testing yourself to get the answers you look for?. 

Because we are looking for cases where SCReAM (and other L4S transports) fail - and we have already found sufficient such cases to raise objections.  We don't need to look further.

The burden of proof is now on you (and the rest of the L4S proponents) to show that these problems have been overcome.    This will require *changes* to L4S, and testing of an implementation of that changed specification.

Sebastian merely listed a few general scenarios where we know L4S does badly.  Those are tests which you should run internally as part of your R&D cycle, and then present results of, in order to give us confidence that L4S can safely be deployed.

 - Jonathan Morton