Re: [tsvwg] feedback and thoughts L4S / SCE

Jonathan Morton <chromatix99@gmail.com> Sat, 28 November 2020 15:50 UTC

Return-Path: <chromatix99@gmail.com>
X-Original-To: tsvwg@ietfa.amsl.com
Delivered-To: tsvwg@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 473CE3A08AE for <tsvwg@ietfa.amsl.com>; Sat, 28 Nov 2020 07:50:41 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.848
X-Spam-Level:
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=unavailable autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id A3fkeEnKhdeA for <tsvwg@ietfa.amsl.com>; Sat, 28 Nov 2020 07:50:39 -0800 (PST)
Received: from mail-lj1-x229.google.com (mail-lj1-x229.google.com [IPv6:2a00:1450:4864:20::229]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 3F4E33A08A5 for <tsvwg@ietf.org>; Sat, 28 Nov 2020 07:50:38 -0800 (PST)
Received: by mail-lj1-x229.google.com with SMTP id q8so515885ljc.12 for <tsvwg@ietf.org>; Sat, 28 Nov 2020 07:50:38 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=7SGDdCjaRrAAQxh2nQBnAP0gOIaI/Rur1ixEmpeXiWk=; b=k7NgTe/nbEkqPqjJSK1ih0dFPORWEO6XhWi6+DtYabUMI5BFkWrmRTD74CmqGzPyCt pVgHmPWdkyLDj4VXluA9AqPXrXchB5U+T9Q5M64NL9xTEWfIlxYT2Wb4JgJ/97LgohYp 8u2nUZF65c39VVfYPDk8Tf/G85+mp6sr7j/aSQsN4hwCIapnHcBJZPoTgP7zrRJdbOW+ fP2tnC2BeMD/wms/zwKVsWLQMHeht2iHyINeuki4CgyxBhGNU2TQq8LbcmX1GPb0TRHR rXkEtG6O/h7Ia0zBhYAAo6dfOIs3bmA1wohPlwUIZhf0j4wmN1xHYco6/7m8CmexkWfb Ci9Q==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=7SGDdCjaRrAAQxh2nQBnAP0gOIaI/Rur1ixEmpeXiWk=; b=oyDxAGUfx60OC246T3J4eWCQVosacSFAja0xTht5B0vjnpCNprMsJh5GpkgXcQdOpS sTtYPNspb/RyVRXY14X2U5KMvrIIIyUVzVZbq/O3Rgvy7xecn7V7eJqrcR/y9aKLGGZo 6eKp/55/9XL9dfvu3MlQMzYrpw3Zi4BYnwD4/c+0UZzCH947IpyR7DsRYAZmCQgU1Ntw EK4pDjruGm/lvWO2Z7ruYp45kD4McCXjKCBQSF9RyhwsRcIHJ2LGbdCzhktYBHjVb/PP 2+JaWloe8M6g13iqLvq9PDJL5ew5b/aGczWkmC8eO+ACmjhNzZ4tRMDmbMqY23jLsiNP V2ig==
X-Gm-Message-State: AOAM533dmk0wUmtRI3WmGwLY2y1g8EHTwLilGPenM20UqPnohEKlIj4z wb0OE+g0vKbqtVE7DUJF/iw=
X-Google-Smtp-Source: ABdhPJyIrqIDqKnde84+zEHeDnv15D+PD3WN0EAJYSCXnj+IVt4IHHlm3NKCAuxv/yccmL9Qtrn+gg==
X-Received: by 2002:a2e:7d0f:: with SMTP id y15mr5654748ljc.401.1606578636885; Sat, 28 Nov 2020 07:50:36 -0800 (PST)
Received: from jonathartonsmbp.lan (178-55-159-67.bb.dnainternet.fi. [178.55.159.67]) by smtp.gmail.com with ESMTPSA id v1sm1101127lfg.252.2020.11.28.07.50.35 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Sat, 28 Nov 2020 07:50:36 -0800 (PST)
Content-Type: text/plain; charset="us-ascii"
Mime-Version: 1.0 (Mac OS X Mail 11.5 \(3445.9.7\))
From: Jonathan Morton <chromatix99@gmail.com>
In-Reply-To: <alpine.DEB.2.20.2011281512350.26384@uplift.swm.pp.se>
Date: Sat, 28 Nov 2020 17:50:34 +0200
Cc: Sebastian Moeller <moeller0@gmx.de>, tsvwg@ietf.org
Content-Transfer-Encoding: quoted-printable
Message-Id: <5A423905-EFD9-4A93-AB46-BACF61FE2D2D@gmail.com>
References: <alpine.DEB.2.20.2011201413100.26384@uplift.swm.pp.se> <9B5474B3-4384-4A20-81C3-5251246AA594@gmx.de> <alpine.DEB.2.20.2011221548210.26384@uplift.swm.pp.se> <066C60AF-39A3-41EF-B9E9-938AA1A707F5@gmx.de> <alpine.DEB.2.20.2011281512350.26384@uplift.swm.pp.se>
To: Mikael Abrahamsson <swmike=40swm.pp.se@dmarc.ietf.org>
X-Mailer: Apple Mail (2.3445.9.7)
Archived-At: <https://mailarchive.ietf.org/arch/msg/tsvwg/wSDAbWXjxnDpWgox3ntTDBwEKUQ>
Subject: Re: [tsvwg] feedback and thoughts L4S / SCE
X-BeenThere: tsvwg@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Transport Area Working Group <tsvwg.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/tsvwg>, <mailto:tsvwg-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/tsvwg/>
List-Post: <mailto:tsvwg@ietf.org>
List-Help: <mailto:tsvwg-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/tsvwg>, <mailto:tsvwg-request@ietf.org?subject=subscribe>
X-List-Received-Date: Sat, 28 Nov 2020 15:50:41 -0000

> On 28 Nov, 2020, at 4:20 pm, Mikael Abrahamsson <swmike=40swm.pp.se@dmarc.ietf.org> wrote:
> 
>> As it turns out there is a nssfq_codel modul for qualcomm`s nss network acellerator cores:
>> see https://forum.openwrt.org/t/ipq806x-nss-drivers/12613/2160
>> 
>> Is that a sufficient response to put tge hypothesis to rest that acelleration techniques do not offer fq_codel?
> 
> This is great news. Do you have more examples?
> 
> I looked over the devices list with that SoC and most of them were 130EUR here (or more). Pretty high-end devices.

The SoC involved here is 5 years old.  Think about that for a moment.

Several of the devices on that list are no longer on the market, because they've been superseded.  So this is hardware that was moderately high-end (in a consumer CPE context) several years ago.  The only reason we're hearing about this nssfq_codel functionality right now is because the method of turning it on finally got reverse-engineered in the open-source world, no thanks to the hardware vendor.  I wish they would stop shooting themselves in the foot on that score.

I have no doubt that similar functionality is actually commonplace in the better CPE SoCs now, certainly in later Qualcomm products.  It's just not emphasised in the spec sheets because the marketing department doesn't understand it, and getting access to it from open source is like getting blood out of a stone.  But it is *there*.

Sebastian pointed out that this constitutes an existence proof for hardware-accelerated fq_codel functionality in reasonably-priced network-edge devices.  We also know that Approximate Fairness technology is available in ISP-grade hardware.  CPE vendors are actively promoting Airtime Fairness technology on the wifi side, which I happen to know comes along with fq_codel as a side effect.

At this point, any claim that fq_codel is not widely deployed in relevant contexts is laughable.

 - Jonathan Morton