From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yb1-xb2c.google.com (mail-yb1-xb2c.google.com [IPv6:2607:f8b0:4864:20::b2c]) (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 BD3E93B2A4 for ; Wed, 12 Jan 2022 20:37:21 -0500 (EST) Received: by mail-yb1-xb2c.google.com with SMTP id g14so10713048ybs.8 for ; Wed, 12 Jan 2022 17:37:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=04+Z3UdIw3aJfGQHBzmGeel6T4m+ZC08uc1PxAPa9G8=; b=pLRefDoa7nwuDWtR3Pp5fKGKlj7Q88XK2N+f8dn72f8Iopmu0Jn/4ugIT3PKkfrF/N 9Z5w7taYbkppZ/xxz38HH6HW/VTWQj6IokqCafk5pDTqNLs+5YUdtEQzLtDwuTx0HKYH 0ZaHxXb4MgxZfx8PfuQbvP1Nxfq+QyFPH86j74aX7zenlRrXGwLik9yWWuPMnpzT7gMv Lg9n7IFiqPD0Khi3PGp0l6zfngdwvkiAomVqaYw67ynq4ipOPb4BEkVtJYIK/n7vH/Nz zxGa5vvVAapnGz7stXvxf8JO1pzxLRe9fMIU9OjmTL0j0M68Nwt5HCEgxxtQd/hyUtwD Qahg== 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=04+Z3UdIw3aJfGQHBzmGeel6T4m+ZC08uc1PxAPa9G8=; b=u6zKWB6pyM03gABVuXxgKpqJjpljNTEmXo8lB4mxBgaCzfwKqwtC+R7rHl81dR5Zh9 KWpHLTX7Nms0MyqfFY4ybXed++Zh+YvaaGnBCH/8Lozs+58x3m445XlvcRlTn6w5RsAa GRia06PRrFPUsYPRkKcEc9pzOJqiADwTYyspnH8pN/GyXh2yBT0MCcLdAd65xysZURyT VN+ghyXSZRHWrbSLCnIEy8mDMW3zAPGbICiy5Fh5Fy5GDlYeSMitHoljZHv0ikoj7ec0 px39+Hyb82059mAk4ykdgzUvUZQLG7Q1MXTW5decmB3rESKMnJ7nscEXOwjl34M0Y+p0 x90w== X-Gm-Message-State: AOAM530iedavkjFTtPHYq+KQNPirX9/Eu1H8dquMb4xzIST4aPwzeg5P El9+GQjjdmnA5oVN6JlBS1DR0KxRCTNzpxsBeK8gPrZRcsI= X-Google-Smtp-Source: ABdhPJxLl3UCvAKDgn1InY1vEHU/0Ya8z3z2tocemdcUYtYTtaMdS2eiESO7DvKSd7dmuRak0sONGWEzZuMWiVL4fNQ= X-Received: by 2002:a25:da46:: with SMTP id n67mr3268477ybf.325.1642037841212; Wed, 12 Jan 2022 17:37:21 -0800 (PST) MIME-Version: 1.0 References: <334460f8-89e7-0ca8-75b8-edbdf30e7961@heavenlysanctuary.com> In-Reply-To: From: Aaron Wood Date: Wed, 12 Jan 2022 17:37:10 -0800 Message-ID: To: Dave Taht Cc: Marco Belmonte , bloat Content-Type: multipart/alternative; boundary="0000000000003bb9b905d56cbac2" Subject: Re: [Bloat] ONTs and ITU - T G.988 X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 13 Jan 2022 01:37:21 -0000 --0000000000003bb9b905d56cbac2 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Can't switches send pause frames back over ethernet? /me googles, and finds: https://en.wikipedia.org/wiki/Ethernet_flow_control On Wed, Jan 12, 2022 at 4:57 PM Dave Taht wrote: > What appeared to be the case was that a ONT had a 50ms buffer at > 100Mbit and was reconfigured to drive a gig and thus only had 5ms. > > At least, that's what the data looked like. This was on a fairly > recent reddit thread a month or two back, that I cannot find right > now. I'm pretty sure it was in the context of eero's > rolling out a working htb+fq_codel implementation finally for the eero > 6, (or maybe it was the comcast AQM?0 and us discovering it didn't do > any good, that the ont was seemingly brutally underbuffered, which > took days of scratching my head.... multiple flent tests... wish I > could find that thread... > > This is kind of ironic, but the structure of the speedtest (8+ flows > with short RTTs) actually could lead naturally to buffers that short > and few would notice. > > Anyway, that sparked me finally going and reading up a bit more about > how ONTs work... > > > On Wed, Jan 12, 2022 at 4:40 PM Marco Belmonte > wrote: > > > > Dave, > > > > Can you describe to me what under buffered would look like? Let's say > > I'm playing Rocket League on a Frontier FIOS connection... When a > > situation arises where the connection is under buffered you might see > > _____. > > > > A lot of interrupts being generated? connections timing out? lag? > > > > I'm guessing that many of the same symptoms that accompanying buffer > > bloat also manifest themselves with buffer bleed? > > > > Marco > > > > > > On 1/12/2022 3:42 PM, Dave Taht wrote: > > > Up until this point I haven't cared all that much about fiber, as mos= t > > > of my observations were that it had "reasonable" buffering and all I > > > could hold in my head was the 802.11 standards. Since cablemodems are > > > well on their way to being fixed, wifi is looking good, and I recentl= y > > > came across an ONT that was actually underbuffered, my holiday readin= g > > > consisted of pounding through a ton of fiber specs like this one: > > > > > > > https://www.itu.int/rec/dologin_pub.asp?lang=3De&id=3DT-REC-G.988-201711-= I!!PDF-E&type=3Ditems > > > > > > There's a lot of promising info in this spec starting from page 104. > > > > > > My 1st question is - are there any ONTs that actually do do pause > > > frames? Or providers that configure for them? > > > > > > My second is - what is a cheap way to setup a lab to emulate a good, > > > common, version of gpon e2e? > > > > > > Third - what OS do these things run? Who makes a "good" one? > > > > > _______________________________________________ > > Bloat mailing list > > Bloat@lists.bufferbloat.net > > https://lists.bufferbloat.net/listinfo/bloat > > > > -- > 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 > _______________________________________________ > Bloat mailing list > Bloat@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/bloat > --0000000000003bb9b905d56cbac2 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Can't switches send pause frames back over ethernet?
/me googles, and finds:


On Wed, Jan 12, 2022 at 4:57= PM Dave Taht <dave.taht@gmail.co= m> wrote:
What appeared to be the case was= that a ONT had a 50ms buffer at
100Mbit and was reconfigured to drive a gig and thus only had 5ms.

At least, that's what the data looked like. This was on a fairly
recent reddit thread a month or two back, that I cannot find right
now. I'm pretty sure it was in the context of eero's
rolling out a working htb+fq_codel implementation finally for the eero
6, (or maybe it was the comcast AQM?0 and us discovering it didn't do any good, that the ont was seemingly brutally underbuffered, which
took days of scratching my head.... multiple flent tests... wish I
could find that thread...

This is kind of ironic, but the structure of the speedtest (8+ flows
with short RTTs) actually could lead naturally to buffers that short
and few would notice.

Anyway, that sparked me finally going and reading up a bit more about
how ONTs work...


On Wed, Jan 12, 2022 at 4:40 PM Marco Belmonte
<marco@= heavenlysanctuary.com> wrote:
>
> Dave,
>
> Can you describe to me what under buffered would look like? Let's = say
> I'm playing Rocket League on a Frontier FIOS connection... When a<= br> > situation arises where the connection is under buffered you might see<= br> > __<Insert DT's Big Brain words here>___.
>
> A lot of interrupts being generated? connections timing out? lag?
>
> I'm guessing that many of the same symptoms that accompanying buff= er
> bloat also manifest themselves with buffer bleed?
>
> Marco
>
>
> On 1/12/2022 3:42 PM, Dave Taht wrote:
> > Up until this point I haven't cared all that much about fiber= , as most
> > of my observations were that it had "reasonable" buffer= ing and all I
> > could hold in my head was the 802.11 standards. Since cablemodems= are
> > well on their way to being fixed, wifi is looking good, and I rec= ently
> > came across an ONT that was actually underbuffered, my holiday re= ading
> > consisted of pounding through a ton of fiber specs like this one:=
> >
> > https://www.itu.int/rec/dologin_pub.asp?lang=3De&id=3DT-REC= -G.988-201711-I!!PDF-E&type=3Ditems
> >
> > There's a lot of promising info in this spec starting from pa= ge 104.
> >
> > My 1st question is - are there any ONTs that actually do do pause=
> > frames? Or providers that configure for them?
> >
> > My second is - what is a cheap way to setup a lab to emulate a go= od,
> > common, version of gpon e2e?
> >
> > Third - what OS do these things run? Who makes a "good"= one?
> >
> _______________________________________________
> Bloat mailing list
> Bloat= @lists.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/bloat


--
I tried to build a better future, a few times:
https://wayforward.archive.org/?sit= e=3Dhttps%3A%2F%2Fwww.icei.org

Dave T=C3=A4ht CEO, TekLibre, LLC
_______________________________________________
Bloat mailing list
Bloat@list= s.bufferbloat.net
https://lists.bufferbloat.net/listinfo/bloat
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