Return-Path: 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 F04721200B5 for ; Thu, 9 Jan 2020 09:41:30 -0800 (PST) X-Virus-Scanned: amavisd-new at amsl.com X-Spam-Flag: NO X-Spam-Score: -8 X-Spam-Level: X-Spam-Status: No, score=-8 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_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 H7mO5xDQJ_bY for ; Thu, 9 Jan 2020 09:41:29 -0800 (PST) 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 40592120019 for ; Thu, 9 Jan 2020 09:41:29 -0800 (PST) Date: Thu, 09 Jan 2020 09:41:28 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=github.com; s=pf2014; t=1578591688; bh=KN3NHSrkTyKxt2NP5vCLV06LOGk0gr9q6oOb154VvTM=; h=Date:From:Reply-To:To:Cc:In-Reply-To:References:Subject:List-ID: List-Archive:List-Post:List-Unsubscribe:From; b=rbTlGFscunn7zdjrkTnrNdjrNEz7li/P7TRZAzWO+VlrS5XXCHTqFp9/19Q5ln24k AtShWGsxynPcaodbv/3myJZLiCvi1iog6CQ2DicBeaqBK6CNfc2gxHOalhqGPCpZrm zPM6w9cQfeMIgWPai5xizh8pI5ZN2JGjgZeDmBUI= From: Matt Corallo Reply-To: quicwg/base-drafts To: quicwg/base-drafts Cc: Subscribed Message-ID: In-Reply-To: References: Subject: Re: [quicwg/base-drafts] MSS Clamping Support (#3330) Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="--==_mimepart_5e1765c83adbc_2a2a3fa7454cd96c1668da"; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: list X-GitHub-Sender: TheBlueMatt X-GitHub-Recipient: quic-issues X-GitHub-Reason: subscribed X-Auto-Response-Suppress: All X-GitHub-Recipient-Address: quic-issues@ietf.org Archived-At: X-BeenThere: quic-issues@ietf.org 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, 09 Jan 2020 17:41:31 -0000 ----==_mimepart_5e1765c83adbc_2a2a3fa7454cd96c1668da Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable I=E2=80=99m not sure if it=E2=80=99s discussed in the PLPMTUD RFC, but on= e relatively simple thing that would improve the state of QUIC is to inst= ruct endpoints they SHOULD NOT use any data-carrying frames for PMTUD and= SHOULD NOT send any data-carrying frames which total over 1280 until the= y have completed PMTUD. This would force endpoints to use 1280-MTU frames= until they=E2=80=99ve used some ping/noncritical/non-latency-critical fr= ames to do PMTUD, avoiding the usual issues with timeout-based PMTUD by s= ending =E2=80=9Cdummy=E2=80=9D traffic that doesn=E2=80=99t block real fl= ows.=0D =0D (Again I=E2=80=99m basing this on a relatively high-level understanding o= f QUIC and having read the MSS section, let me know if this of way off ba= se).=0D =0D > On Jan 9, 2020, at 10:46, ianswett wrote:=0D= > =0D > =EF=BB=BF=0D > If a smaller MTU is faster, but it's larger than the 1200 byte UDP payl= oad minimum, you could clamp to the performance optimal size for QUIC flo= ws and let them figure it out with PLPMTUD if they implement it.=0D > =0D > Ideally, clients can remember what the MTU was from last time they conn= ected to a given hostname, and use that to speed future PMTU. Similarly, = clients could try to determine the max MTU that ever works for any non-lo= cal connection and use that as an upper bound. But both of those are opti= mizations.=0D > =0D > I agree with @martinthomson that I can't think of any change that would= help the situation that's in scope for QUIC v1.=0D > =0D > =E2=80=94=0D > You are receiving this because you authored the thread.=0D > Reply to this email directly, view it on GitHub, or unsubscribe.=0D =0D =0D -- =0D You are receiving this because you are subscribed to this thread.=0D Reply to this email directly or view it on GitHub:=0D https://github.com/quicwg/base-drafts/issues/3330#issuecomment-572672307= ----==_mimepart_5e1765c83adbc_2a2a3fa7454cd96c1668da Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable I=E2=80=99m not sure if it=E2=80=99s discussed in the PLPMTUD RFC, but on= e relatively simple thing that would improve the state of QUIC is to inst= ruct endpoints they SHOULD NOT use any data-carrying frames for PMTUD and= SHOULD NOT send any data-carrying frames which total over 1280 until the= y have completed PMTUD. This would force endpoints to use 1280-MTU frames= until they=E2=80=99ve used some ping/noncritical/non-latency-critical fr= ames to do PMTUD, avoiding the usual issues with timeout-based PMTUD by s= ending =E2=80=9Cdummy=E2=80=9D traffic that doesn=E2=80=99t block real fl= ows.
=0D
=0D (Again I=E2=80=99m basing this on a relatively high-level understanding o= f QUIC and having read the MSS section, let me know if this of way off ba= se).
=0D
=0D > On Jan 9, 2020, at 10:46, ianswett <notifications@github.com> = wrote:
=0D >
=0D > =EF=BB=BF
=0D > If a smaller MTU is faster, but it's larger than the 1200 byte U= DP payload minimum, you could clamp to the performance optimal size for Q= UIC flows and let them figure it out with PLPMTUD if they implement it.=0D >
=0D > Ideally, clients can remember what the MTU was from last time they c= onnected to a given hostname, and use that to speed future PMTU. Similarl= y, clients could try to determine the max MTU that ever works for any non= -local connection and use that as an upper bound. But both of those are o= ptimizations.
=0D >
=0D > I agree with @martinthomson that I can't think of any change tha= t would help the situation that's in scope for QUIC v1.
=0D >
=0D > =E2=80=94
=0D > You are receiving this because you authored the thread.
=0D > Reply to this email directly, view it on GitHub, or unsubscribe.
= =0D =0D =0D

&m= dash;
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Reply to this email directly, view it on= GitHub, or unsubscribe.3D""

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