Re: Two Notable Ack Frequency Issues

Martin Thomson <> Mon, 13 September 2021 00:00 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id AA6E83A09EF for <>; Sun, 12 Sep 2021 17:00:18 -0700 (PDT)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -2.101
X-Spam-Status: No, score=-2.101 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, RCVD_IN_MSPIKE_H2=-0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: (amavisd-new); dkim=pass (2048-bit key) header.b=YuFK5NvB; dkim=pass (2048-bit key) header.b=bIHUesLN
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id OjFkmHHD3ZSL for <>; Sun, 12 Sep 2021 17:00:13 -0700 (PDT)
Received: from ( []) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by (Postfix) with ESMTPS id B797C3A09EC for <>; Sun, 12 Sep 2021 17:00:13 -0700 (PDT)
Received: from compute5.internal (compute5.nyi.internal []) by mailout.nyi.internal (Postfix) with ESMTP id 5098D5C00D9 for <>; Sun, 12 Sep 2021 20:00:12 -0400 (EDT)
Received: from imap41 ([]) by compute5.internal (MEProxy); Sun, 12 Sep 2021 20:00:12 -0400
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; h=mime-version:message-id:in-reply-to:references:date:from:to :subject:content-type; s=fm3; bh=qcdAWHPwRMQ1+YJ9SeeYjqYd0NIKvA4 4OW6Mcka11MM=; b=YuFK5NvBXMGPPWgj6P8CkxSVTedHoUoQdcOWlaJuiyPnc1g o7EWvufjZKPWtuUne2G6/TndL+qQtrKo0/UlEhAFQ0t5eJm0mVC88kHvF1J0PHzj csj06ornkPbPogD8EznnrK6XXrdRUcG4TOpbRxnWffpjuKfWhEpnH/MswssW6rfs anMMK4NJpmhOnX959DVgioPPXtxQfnIhxTzsnAIr6KogCnD5Fe7TrH/7VTn07xHN n4N0hGEGJBxJY4Db3Tml3wGqj4JYnzpK6K9hqTx1n4V4Hxzt5Qv2qoeWr8uzhZaz Qd3lZGcooLpAPDoIzMeWBmMtSpAnVVoFviM997w==
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=; h=content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm3; bh=qcdAWH PwRMQ1+YJ9SeeYjqYd0NIKvA44OW6Mcka11MM=; b=bIHUesLNAexlvUBCuuUmAh U7y+GS91pjzWTms8ASHGURa5ZeQd1kE0ZbNHvkeErB9aoiKapvdT2/+TMbIt49Yn PWJVpref7glpvc/0AkbEHgdzJ49j0qt3fJZcgXx9ETa7x94oR3z6Af7kHuIHwidC Rr1Tbu0IPhucJ/n+klxawBUk/n17FcpvkG6ig39E9Ct4ZVNyU+/c11nUqYvh63Nt vf25EtvWp5W97KkkFBsVsS64qeLpJreyhIdx1QdrdKuIKNG1359ptKQrK1kspYTl ni9sVxD9XGCHGd7C+dV8gt//HKGawELhh9/eQ7Rvu4w2Gn1Dau7h5bdi2Zj9xnLg ==
X-ME-Sender: <xms:i5Q-YToNRbUMpSKFhSweLroa1IXvi-0pR-P8K9LSMszx_fPi1traRg> <xme:i5Q-YdrZtv39riFHN6H5OjYHkFSmlu6V3KJHrh6C_Wo0uGawRGpXAPIqbDfx0nl-Q i5UkSsvVfm9qHXQS98>
X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvtddrudegiedgvdelucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucenucfjughrpefofgggkfgjfhffhffvufgtsehttd ertderredtnecuhfhrohhmpedfofgrrhhtihhnucfvhhhomhhsohhnfdcuoehmtheslhho figvnhhtrhhophihrdhnvghtqeenucggtffrrghtthgvrhhnpedtgefhkeegfffhteefje ekveefteehheelgeehheevleefteefieekfefgjedvgeenucffohhmrghinhepghhithhh uhgsrdgtohhmnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrh homhepmhhtsehlohifvghnthhrohhphidrnhgvth
X-ME-Proxy: <xmx:i5Q-YQP27CZh55y_YpVRJlOjVgvUqHagEGZ_8IAjgj49Rdb6xjRGLQ> <xmx:i5Q-YW7dkiGAG5wrG8seCaEJwzrW6FGpm0v0rbKgFhqrW7hBjL7GEg> <xmx:i5Q-YS7gJAADB_ZL1fRYmxy3fmeSrE_uETLF4wodP9ipwk8mkfK09A> <xmx:jJQ-YUEl0LyfbnO_qIUinB101nFRJx-cTbjUkvv3bt01Iq_QjTXJDQ>
Received: by mailuser.nyi.internal (Postfix, from userid 501) id E56923C0821; Sun, 12 Sep 2021 20:00:11 -0400 (EDT)
X-Mailer: Webmail Interface
User-Agent: Cyrus-JMAP/3.5.0-alpha0-1229-g7ca81dfce5-fm-20210908.005-g7ca81dfc
Mime-Version: 1.0
Message-Id: <>
In-Reply-To: <>
References: <>
Date: Mon, 13 Sep 2021 09:59:52 +1000
From: Martin Thomson <>
Subject: Re: Two Notable Ack Frequency Issues
Content-Type: text/plain
Archived-At: <>
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Main mailing list of the IETF QUIC working group <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Mon, 13 Sep 2021 00:00:19 -0000

The first seems benign.

The second is pure scope creep and I'm opposed to adding it (as I am opposed to IMMEDIATE_ACK, which has not been discussed on the list thus far from what I can see, though that is less objectionable).  The discussion that is available really doesn't motivate it more than "that might be nice".  I would have expected a lot more discussion about what this is supposed to achieve, how an endpoint might decide that it is necessary to use the feature, under what conditions it might be inadvisable, precedence (NO_ACK > IMMEDIATE_ACK: why?), and probably some other stuff I haven't thought of yet.

On Sun, Sep 12, 2021, at 09:50, Ian Swett wrote:
> Most of the outstanding design issues were discussed at the last IETF 
> meeting and had clear resolutions.  As such, I think we're close to 
> being ready to ship this draft.
> One issue not discussed(#48 
> <>) regarding ECN CE 
> and a new issue(#65 
> <>) adding a NO_ACK 
> frame are notable changes and have not received wide discussion, so I 
> wanted to publicize them here before merging any changes.
> I think both changes are heading in the right direction, and both have 
> PRs you can comment on.
> I'd like to merge these in a week or so if there's no pushback, so 
> please take a look when you have time.
> Thanks, Ian