Re: [quicwg/base-drafts] Recovery uses both time and packet thresholds (#1974)

MikkelFJ <notifications@github.com> Wed, 07 November 2018 07:50 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 7F054130E30 for <quic-issues@ietfa.amsl.com>; Tue, 6 Nov 2018 23:50:33 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -8.47
X-Spam-Level:
X-Spam-Status: No, score=-8.47 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.47, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HTML_MESSAGE=0.001, MAILING_LIST_MULTI=-1, RCVD_IN_DNSWL_HI=-5, 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 vWjcr3v8Uixt for <quic-issues@ietfa.amsl.com>; Tue, 6 Nov 2018 23:50:31 -0800 (PST)
Received: from out-1.smtp.github.com (out-1.smtp.github.com [192.30.252.192]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id AECC8130E1C for <quic-issues@ietf.org>; Tue, 6 Nov 2018 23:50:30 -0800 (PST)
Date: Tue, 06 Nov 2018 23:50:29 -0800
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=github.com; s=pf2014; t=1541577029; bh=d4/zwdRBn+o0DYZzfbG21/AWGgjpohYEF0caFi00NK0=; h=Date:From:Reply-To:To:Cc:In-Reply-To:References:Subject:List-ID: List-Archive:List-Post:List-Unsubscribe:From; b=ARRbzEcPiObKKarvUJbWT4GN5o00PFdkB5McylnGFbRAgkSARdLgmFiIxq0lhBTQx EpRvM8Xk0TaL7b5lcAB/sshhIBNZy1RhkTkSZZ0zHq2y2RHM5gBlEvEfmH8b2CTrAg lf6xz02bnamd2U68VpgfroBf/owyQDJeyuNLhp34=
From: MikkelFJ <notifications@github.com>
Reply-To: quicwg/base-drafts <reply+0166e4aba54ce79e944677413356878807c603210443f1a892cf0000000117fa5b4592a169ce1684c1ce@reply.github.com>
To: quicwg/base-drafts <base-drafts@noreply.github.com>
Cc: Subscribed <subscribed@noreply.github.com>
Message-ID: <quicwg/base-drafts/pull/1974/review/172368439@github.com>
In-Reply-To: <quicwg/base-drafts/pull/1974@github.com>
References: <quicwg/base-drafts/pull/1974@github.com>
Subject: Re: [quicwg/base-drafts] Recovery uses both time and packet thresholds (#1974)
Mime-Version: 1.0
Content-Type: multipart/alternative; boundary="--==_mimepart_5be299456afb3_5a143fe8268d45c0584799"; charset="UTF-8"
Content-Transfer-Encoding: 7bit
Precedence: list
X-GitHub-Sender: mikkelfj
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/TLNIMf__lcZalJBHp3fgsG_Tbno>
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: Wed, 07 Nov 2018 07:50:38 -0000

mikkelfj commented on this pull request.



>  as a fraction of the round-trip time (kTimeReorderingFraction), is 1/8.
 
-An endpoint SHOULD set the timer such that a packet is marked as lost no earlier
-than 1.125 * max(SRTT, latest_RTT) since when it was sent.
+An endpoint SHOULD declare packets lost no earlier than
+1.125 * max(SRTT, latest_RTT) after when they were sent.  If packets sent prior
+to the largest acknowledged packet cannot yet be declared lost, then a timer
+SHOULD be set for the remainint time.

remaining

> @@ -312,16 +292,10 @@ Using max(SRTT, latest_RTT) protects from the two following cases:
 * the latest RTT sample is higher than the SRTT, perhaps due to a sustained
   increase in the actual RTT, but the smoothed SRTT has not yet caught up.
 
-The 1.125 multiplier increases reordering resilience. Implementers MAY
-experiment with using other multipliers, bearing in mind that a lower multiplier
-reduces reordering resilience and increases spurious retransmissions, and a
-higher multiplier increases loss recovery delay.
-
-This mechanism is based on Early Retransmit for TCP {{?RFC5827}}. However,
-{{?RFC5827}} does not include the timer described above. Early Retransmit is
-prone to spurious retransmissions due to its reduced reordering resilence
-without the timer. This observation led Linux TCP implementers to implement a
-timer for TCP as well, and this document incorporates this advancement.
+Implementers MAY experiment with using other reordering fractoins, bearing

fractions

-- 
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/1974#pullrequestreview-172368439