Re: [quicwg/base-drafts] A pacing algorithm (#3630)

Martin Thomson <notifications@github.com> Thu, 07 May 2020 00:59 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 284433A0DF2 for <quic-issues@ietfa.amsl.com>; Wed, 6 May 2020 17:59:56 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.555
X-Spam-Level:
X-Spam-Status: No, score=-1.555 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, DKIM_VALID_EF=-0.1, HTML_IMAGE_ONLY_20=1.546, HTML_MESSAGE=0.001, MAILING_LIST_MULTI=-1, RCVD_IN_MSPIKE_H2=-0.001, 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 J-1_LCfvwpnE for <quic-issues@ietfa.amsl.com>; Wed, 6 May 2020 17:59:54 -0700 (PDT)
Received: from out-4.smtp.github.com (out-4.smtp.github.com [192.30.252.195]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id E5AE33A0C6B for <quic-issues@ietf.org>; Wed, 6 May 2020 17:59:53 -0700 (PDT)
Received: from github-lowworker-52827f8.ash1-iad.github.net (github-lowworker-52827f8.ash1-iad.github.net [10.56.108.24]) by smtp.github.com (Postfix) with ESMTP id 4FD3BC60ACF for <quic-issues@ietf.org>; Wed, 6 May 2020 17:59:52 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=github.com; s=pf2014; t=1588813192; bh=7Hp+KWnw9o83f1KU1XcBJCvBJ79xTsDfU2QqxC1/E1Q=; h=Date:From:Reply-To:To:Cc:In-Reply-To:References:Subject:List-ID: List-Archive:List-Post:List-Unsubscribe:From; b=hw53uMDuRZXrChpN0BDDIKx2i793Ca+4HQF5iosqYt3fy0ka+EXghf+Kk79d5S6Oy npd5riQBLraBFdfwvd4ShVG+SUkGRJBnNWRwn7v247WAPENNzmzqK094/ewaIQgXVI jSU292Weay0hzZ052iHJFk/2Xq0/72EP/AeNg5sQ=
Date: Wed, 06 May 2020 17:59:52 -0700
From: Martin Thomson <notifications@github.com>
Reply-To: quicwg/base-drafts <reply+AFTOJK7ORG4JCRPHFYH2HVF4X47IREVBNHHCJCUB5E@reply.github.com>
To: quicwg/base-drafts <base-drafts@noreply.github.com>
Cc: Subscribed <subscribed@noreply.github.com>
Message-ID: <quicwg/base-drafts/pull/3630/c624968569@github.com>
In-Reply-To: <quicwg/base-drafts/pull/3630@github.com>
References: <quicwg/base-drafts/pull/3630@github.com>
Subject: Re: [quicwg/base-drafts] A pacing algorithm (#3630)
Mime-Version: 1.0
Content-Type: multipart/alternative; boundary="--==_mimepart_5eb35d883f821_684b3fdadc0cd96488391e"; charset="UTF-8"
Content-Transfer-Encoding: 7bit
Precedence: list
X-GitHub-Sender: martinthomson
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/Ax6wHWUeqKHDB-67ePZfJ6KbzWM>
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: Thu, 07 May 2020 00:59:56 -0000

Oh, I went back to my code and found why I wanted N.  With the same example as before, you are sending 10 packets per second and the congestion window doubles.  If you apply the formula in one way, you can get some odd spikes in the rate.  Say that you measure over 10s (i.e., 100p/10s), and the rate doubles.  If you attempt to reach the new target in the next second (200p/10s), your send rate goes up by a factor of 10 briefly.  There is less incentive to do that sort of compensation if you have been sending at a higher rate previously.

-- 
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/pull/3630#issuecomment-624968569