Re: [quicwg/base-drafts] Only send one immediate ACK after reordering (#3357)

Gorry Fairhurst <notifications@github.com> Mon, 03 February 2020 15:26 UTC

Return-Path: <noreply@github.com>
X-Original-To: quic-issues@ietfa.amsl.com
Delivered-To: quic-issues@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 4B901120961 for <quic-issues@ietfa.amsl.com>; Mon, 3 Feb 2020 07:26:21 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -6.382
X-Spam-Level:
X-Spam-Status: No, score=-6.382 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HTML_IMAGE_ONLY_24=1.618, HTML_MESSAGE=0.001, MAILING_LIST_MULTI=-1, RCVD_IN_DNSWL_HI=-5, SPF_HELO_NONE=0.001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=github.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 qxuBJRoCo-g3 for <quic-issues@ietfa.amsl.com>; Mon, 3 Feb 2020 07:26:19 -0800 (PST)
Received: from out-7.smtp.github.com (out-7.smtp.github.com [192.30.252.198]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id B134512096F for <quic-issues@ietf.org>; Mon, 3 Feb 2020 07:26:19 -0800 (PST)
Received: from github-lowworker-25680bd.va3-iad.github.net (github-lowworker-25680bd.va3-iad.github.net [10.48.17.61]) by smtp.github.com (Postfix) with ESMTP id 95C222C1EF2 for <quic-issues@ietf.org>; Mon, 3 Feb 2020 07:26:18 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=github.com; s=pf2014; t=1580743578; bh=DOY+b0+ZuK4bdb8kuSxwcQmGb4N1dQ/dkdK07rk2oio=; h=Date:From:Reply-To:To:Cc:In-Reply-To:References:Subject:List-ID: List-Archive:List-Post:List-Unsubscribe:From; b=UkpJ/IRuPBF1CT/Lg8rfQ/ppmsd5GZrP5GOtBebZO8hWGsfE+TiF5nkQ+gL/K/KB3 f1JrAfkZpKZFBpRMYBvZ8mCJa5nSyW1vOKLi8/lJQgjxzPezP0fUXjzgsUKj4VRyNe zmy41LYrf/0OYmurfR2Z3qheoJbwP0A+keltJXwQ=
Date: Mon, 03 Feb 2020 07:26:18 -0800
From: Gorry Fairhurst <notifications@github.com>
Reply-To: quicwg/base-drafts <reply+AFTOJK63GNHCXGCQ2DIS42N4IVXBVEVBNHHCBYECWE@reply.github.com>
To: quicwg/base-drafts <base-drafts@noreply.github.com>
Cc: Subscribed <subscribed@noreply.github.com>
Message-ID: <quicwg/base-drafts/issues/3357/581467628@github.com>
In-Reply-To: <quicwg/base-drafts/issues/3357@github.com>
References: <quicwg/base-drafts/issues/3357@github.com>
Subject: Re: [quicwg/base-drafts] Only send one immediate ACK after reordering (#3357)
Mime-Version: 1.0
Content-Type: multipart/alternative; boundary="--==_mimepart_5e383b9a8fc09_5d103fc8ca8cd96c97982"; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: list
X-GitHub-Sender: gorryfair
X-GitHub-Recipient: quic-issues
X-GitHub-Reason: subscribed
X-Auto-Response-Suppress: All
X-GitHub-Recipient-Address: quic-issues@ietf.org
Archived-At: <https://mailarchive.ietf.org/arch/msg/quic-issues/y-syHKRvQIYRHQZDKH-WmRL6Vq8>
X-BeenThere: quic-issues@ietf.org
X-Mailman-Version: 2.1.29
List-Id: Notification list for GitHub issues related to the QUIC WG <quic-issues.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/quic-issues>, <mailto:quic-issues-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/quic-issues/>
List-Post: <mailto:quic-issues@ietf.org>
List-Help: <mailto:quic-issues-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/quic-issues>, <mailto:quic-issues-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 03 Feb 2020 15:26:21 -0000

My point is I think this is the wrong direction. I think n=2 is unnecessarily restrictive as a default, and does have unwanted performance impacts in some places. 

I think the case of loss for a burst of one packet that you mention is handed by the timer. The congestion impact is minor.

While I agree for n=2 the method doesn't make much difference, for n=10, it would make a difference - because I'd expect it to be Important to be able to robustly detect and respond after congestion, I'm not sure it matters if the intention is to send DupACK+k immediate ACks or to send ACKs more frequently for some proportion of a RTT. 

-- 
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/quicwg/base-drafts/issues/3357#issuecomment-581467628