From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm1-x330.google.com (mail-wm1-x330.google.com [IPv6:2a00:1450:4864:20::330]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id B69433CB35 for ; Sat, 11 Dec 2021 11:25:48 -0500 (EST) Received: by mail-wm1-x330.google.com with SMTP id g191-20020a1c9dc8000000b0032fbf912885so8757744wme.4 for ; Sat, 11 Dec 2021 08:25:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=NCOh5igFsMDO8vC85EsY7Lb9lBfpJE+Jz8q1Q6f88tY=; b=rzJm3fbOE6vwyQ0u+s2kJjlEut1xqAJ5sv6SQus9127/nu4c7ly47sE870Zo2IEgfi dxR1uDAZSwnk2CvLXJVKoThtnQqpJCwemREvE515NSM91ZVAwXgHNxIMsCiaLtk5dp+4 /xoHStCNWyL9nfULpTxDBDxI21g6z2dCpWHXSE3iVZb4ZflZvadvklfE4V54dOxWspW4 mwnY2xh8wxbsAjIUfW/TY/pySxW1/4jdLy6joPbi03Hc6VSSOV/oXRNXkdDJ/HYuHOrN IxOJbmXSPT683sfjy7N+iLoh/ZadGZWcxgw0ZpltVqp3D4P99nbdRuiV+ZoUl15hLyd3 Lynw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=NCOh5igFsMDO8vC85EsY7Lb9lBfpJE+Jz8q1Q6f88tY=; b=tjwqVP+tK5DRRk48l5JhS1MIQC2EGBl7/1OFALsHN1cgQ7v60y3WUO7gSyfFWmzwuR DrukdbKJ/j+azkhklUizQ+pevC7Op7xdE/6eacDYySP+a8QCvn8JwC5rSYNndX29IYq3 8eKBz3Ct5ZHxauieIl+BEXYd/pHPSb0hXbA7FZ0Ov7c5944dsHonja42fxYvizx3eeh4 DfFnfNFAC7fibQSN2R51Fbc7ZxqR1Sb30ecMwvpzP3+iSt73CGu5InDUtk3eL2wMic/j qu+cLFPFWXHnIWJD/RmSDEcZAExgE1mf7EykMqRRDwYRP+DZrdQjVJN3y0cudumbLyxC E00w== X-Gm-Message-State: AOAM530N+wn6cz1STK4beX5A/Smd+3migJIlOcvbfeNjXKH+7h+WCXao Uynb2GhckMrRK3L/MFucq0ZpukogQxagGlPngrnrFQ== X-Google-Smtp-Source: ABdhPJzW1ZgiQcGqfJ2FWrGfG+4LOowd+tLK97YxMvdy/PC77QIPxkexdMiPjEoPSaYcDMIadyk1nco5Mq1ex28fdL8= X-Received: by 2002:a05:600c:4e8f:: with SMTP id f15mr24722464wmq.116.1639239947079; Sat, 11 Dec 2021 08:25:47 -0800 (PST) MIME-Version: 1.0 References: <18B2DB86-D603-4D9A-8E6D-E92093477AA6@gmx.de> In-Reply-To: <18B2DB86-D603-4D9A-8E6D-E92093477AA6@gmx.de> From: Matt Mathis Date: Sat, 11 Dec 2021 08:25:35 -0800 Message-ID: To: Sebastian Moeller Cc: =?UTF-8?Q?Dave_T=C3=A4ht?= , Rpm Content-Type: multipart/alternative; boundary="000000000000c045e005d2e14a2e" Subject: Re: [Rpm] actively measuring owd successfully using icmp X-BeenThere: rpm@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: revolutions per minute - a new metric for measuring responsiveness List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 11 Dec 2021 16:25:48 -0000 --000000000000c045e005d2e14a2e Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable icmp_timestamp has not been removed, and in Linux it is still present in the shared icmp code used by both IPv4 and IPv6. More likely a bug that has never been noticed, because nobody bothered to test it. I note that most icmp documentation doesn't even mention it's existence. If a kernel bug, most likely a corrupted checksum. But my bet would be code outright missing from the library. Good luck! Thanks, --MM-- The best way to predict the future is to create it. - Alan Kay We must not tolerate intolerance; however our response must be carefully measured: too strong would be hypocritical and risks spiraling out of control; too weak risks being mistaken for tacit approval. On Sat, Dec 11, 2021 at 5:20 AM Sebastian Moeller via Rpm < rpm@lists.bufferbloat.net> wrote: > Two notes. > 1) Technically it is not OWD that is measured, but "OWD + unknown_offset"= , > but since the goal is to evaluate the delta between the current delay and= a > history delay aggregate, the unknown offset does not matter too much, and > as it turns out quite a lot of the tested reflectors are reasonably well > synchronized already (to my utter, utter surprise). > 2) It appears that ICMPv6 removed the timestamp option, does anybody here > have a link to the discussions that lead to this somewhat unfortunate > decision? > > Best Regards > Sebastian > > > > On Dec 11, 2021, at 13:59, Dave Taht via Rpm > wrote: > > > > Somewhere in this thread the actual working method is buried, but: > > > > https://forum.openwrt.org/t/cake-w-adaptive-bandwidth/108848/944 > > > > -- > > I tried to build a better future, a few times: > > https://wayforward.archive.org/?site=3Dhttps%3A%2F%2Fwww.icei.org > > > > Dave T=C3=A4ht CEO, TekLibre, LLC > > _______________________________________________ > > Rpm mailing list > > Rpm@lists.bufferbloat.net > > https://lists.bufferbloat.net/listinfo/rpm > > _______________________________________________ > Rpm mailing list > Rpm@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/rpm > --000000000000c045e005d2e14a2e Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
icmp_timestamp has not been removed, and in Linux it is st= ill present in the shared icmp code used by both IPv4 and IPv6.

More likely a bug that has never been noticed, because nobody bothe= red=C2=A0to test it.=C2=A0 I note that most icmp documentation doesn't = even mention=C2=A0it's existence.

If a kernel = bug, most likely a corrupted checksum.=C2=A0 But my bet would be code outri= ght missing from the library.

Good luck!

Thanks,
--MM--
The best way to predict the future is to create it. = =C2=A0- Alan Kay

We must not tolerate intolerance;
=C2=A0 =C2=A0 =C2=A0 =C2=A0however our response must be carefully meas= ured:=C2=A0
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 too strong = would be hypocritical and risks spiraling out of control;
=C2=A0 = =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 too weak risks being mistaken for tacit = approval.


On Sat, Dec 11, 2021= at 5:20 AM Sebastian Moeller via Rpm <rpm@lists.bufferbloat.net> wrote:
Two notes.
1) Technically it is not OWD that is measured, but "OWD + unknown_offs= et", but since the goal is to evaluate the delta between the current d= elay and a history delay aggregate, the unknown offset does not matter too = much, and as it turns out quite a lot of the tested reflectors are reasonab= ly well synchronized already (to my utter, utter surprise).
2) It appears that ICMPv6 removed the timestamp option, does anybody here h= ave a link to the discussions that lead to this somewhat unfortunate decisi= on?

Best Regards
=C2=A0 =C2=A0 =C2=A0 =C2=A0 Sebastian


> On Dec 11, 2021, at 13:59, Dave Taht via Rpm <rpm@lists.bufferbloat.net>= wrote:
>
> Somewhere in this thread the actual working method is buried, but:
>
> https://forum.openwrt.org/t/cak= e-w-adaptive-bandwidth/108848/944
>
> --
> I tried to build a better future, a few times:
> https://wayforward.archive.org= /?site=3Dhttps%3A%2F%2Fwww.icei.org
>
> Dave T=C3=A4ht CEO, TekLibre, LLC
> _______________________________________________
> Rpm mailing list
> Rpm@lis= ts.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/rpm

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