Re: [quicwg/base-drafts] DPLPMTU merge tweaks (#3702)

Gorry Fairhurst <> Thu, 28 May 2020 03:01 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id 942DA3A0B54 for <>; Wed, 27 May 2020 20:01:04 -0700 (PDT)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -1.696
X-Spam-Status: No, score=-1.696 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_28=1.404, HTML_MESSAGE=0.001, MAILING_LIST_MULTI=-1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Authentication-Results: (amavisd-new); dkim=pass (1024-bit key)
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id 7wTLC5W8aj9G for <>; Wed, 27 May 2020 20:01:03 -0700 (PDT)
Received: from ( []) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by (Postfix) with ESMTPS id 47BCE3A0B50 for <>; Wed, 27 May 2020 20:01:03 -0700 (PDT)
Received: from ( []) by (Postfix) with ESMTP id 7A3EAC60993 for <>; Wed, 27 May 2020 20:01:02 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=pf2014; t=1590634862; bh=UnX/Ft621wQmAX1MX4qsOnhREXXDRGQR/zJdcHpZne0=; h=Date:From:Reply-To:To:Cc:In-Reply-To:References:Subject:List-ID: List-Archive:List-Post:List-Unsubscribe:From; b=RkMxuGnncuFStOmGr+XgFPBnNAGr/fxYHDLF5+49FNq1DibxL7VX4wWh6+Gz2oq8K n2VHn8UcTgy3Pn0upHhIj0LREGLSZ8tfC5wJWfm4L98Oh2Mg0gVk+cudPhXFwTghep Db5IctiRCEbCeKVqR1SdKT+ajltTHqaZvi9M/9Cw=
Date: Wed, 27 May 2020 20:01:02 -0700
From: Gorry Fairhurst <>
Reply-To: quicwg/base-drafts <>
To: quicwg/base-drafts <>
Cc: Subscribed <>
Message-ID: <quicwg/base-drafts/pull/3702/review/>
In-Reply-To: <quicwg/base-drafts/pull/>
References: <quicwg/base-drafts/pull/>
Subject: Re: [quicwg/base-drafts] DPLPMTU merge tweaks (#3702)
Mime-Version: 1.0
Content-Type: multipart/alternative; boundary="--==_mimepart_5ecf296e6b4cf_1d213fa2bb2cd95c256882"; 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
Archived-At: <>
X-Mailman-Version: 2.1.29
List-Id: Notification list for GitHub issues related to the QUIC WG <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Thu, 28 May 2020 03:01:05 -0000

@gorryfair commented on this pull request.

> @@ -3900,42 +3917,82 @@ determines that the quoted packet has actually been lost.
 ## Datagram Packetization Layer PMTU Discovery
-Section 6.3 of {{!DPLPMTUD}} provides considerations for implementing Datagram
-Packetization Layer PMTUD (DPLPMTUD) with QUIC.
+When implementing the algorithm in Section 5 of {{!DPLPMTUD}}, the initial value
+of BASE_PMTU SHOULD be consistent with the minimum QUIC packet size. The
+MIN_PLPMTU is the same as the BASE_PMTU.
+QUIC endpoints implementing DPLPMTUD maintain a maximum packet size (DPLPMTUD
+MPS) for each combination of local and remote IP addresses.
+If a QUIC endpoint determines that the PLPMTU between any pair of local and
+remote IP addresses has fallen below the size needed to support the minimum QUIC
+packet size (BASE_PLPMTU), it MUST immediately cease sending QUIC packets,
+except for DPLPMTUD probe packets, on the affected path. An endpoint MAY

I am fine to remove: DPLPMTUD will anyway send some "probes" after it thinks a blackhole is detected, to confirm if the black hole exists. Once confirmed I understand QUIC will cease sending.

You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub: