From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oa0-x233.google.com (mail-oa0-x233.google.com [IPv6:2607:f8b0:4003:c02::233]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id 5782E21F249; Tue, 29 Apr 2014 09:57:32 -0700 (PDT) Received: by mail-oa0-f51.google.com with SMTP id l6so569763oag.10 for ; Tue, 29 Apr 2014 09:57:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type; bh=wdzfQaFg8FjLD7FJjqn0TmoQ/ScmW5GPi90O3qWN9G4=; b=VpP4D3kzIb36OHBdRAn64XS3z9AYzC3QU03CLW08kFRQrs1DLkiZUxXLvQMaAjvRnJ coqbtU9pzoK4BWFvO06ql6DvrUI2KrnZxbgmsa2+rfn8BRv7G9E8hKKhzlfL37FkjvE3 7wHovZpuBIQB/JhZpv9nCUVdLLAGYOZxhwPZfQcKJ1SNGfFHKYlHFPXRfVvVGHhdZn1p Jgz/LWp2CeDYl5coPHlI9wtNpeCahr998rPM/QSlYzXr05lMoNl7jTZQyGfeX670d1Hk IPTQXfkx2bitg+MciIs0BJe9JYP4cDFSF3qIKsgq88usjCs6+Dy9oFSUiYbuSztzmgEp iCuA== MIME-Version: 1.0 X-Received: by 10.182.27.133 with SMTP id t5mr2984095obg.65.1398790651583; Tue, 29 Apr 2014 09:57:31 -0700 (PDT) Sender: gettysjim@gmail.com Received: by 10.76.73.100 with HTTP; Tue, 29 Apr 2014 09:57:31 -0700 (PDT) In-Reply-To: References: <4130D000-FE28-4A5E-B824-3371C1602472@cisco.com> Date: Tue, 29 Apr 2014 12:57:31 -0400 X-Google-Sender-Auth: GeVG0icCwQpqzrRjNIaq90cCa1E Message-ID: From: Jim Gettys To: Mikael Abrahamsson Content-Type: multipart/alternative; boundary=001a113356c6e7e37404f8315305 Cc: "aqm@ietf.org" , "Fred Baker \(fred\)" , "cerowrt-devel@lists.bufferbloat.net" , bloat Subject: Re: [Cerowrt-devel] [Bloat] [aqm] the side effects of 330ms lag in the real world X-BeenThere: cerowrt-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: Development issues regarding the cerowrt test router project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 29 Apr 2014 16:57:32 -0000 --001a113356c6e7e37404f8315305 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Tue, Apr 29, 2014 at 12:44 PM, Jim Gettys wrote: > > > > On Tue, Apr 29, 2014 at 3:56 AM, Mikael Abrahamsson wro= te: > >> On Tue, 29 Apr 2014, Fred Baker (fred) wrote: >> >> Well, we could discuss international communications. I happen to be at >>> Infocom in Toronto, VPN=E2=80=99d into Cisco San Jose, and did a ping t= o you: >>> >> >> Yes, but as soon as you hit the long distance network the latency is the >> same regardless of access method. So while I agree that understanding th= e >> effect of latency is important, it's no longer a meaningful way of selli= ng >> fiber access. If your last-mile is fiber instead of ADSL2+ won't improve >> your long distance latency. > > > =E2=80=8BFIOS bufferbloat is a problem too. > > Measured bufferbloat, symmetric 25/25 service in New Jersey at my inlaw's > house is 200ms (on the ethernet port of the Actiontec router provided by > Verizon). So latency under load is the usual problem. > > Why would you think the GPON guys are any better in principle than cable > or DSL? Cable and DSL may be somewhat worse, just because it is older an= d > downward compatibility means that new modems on low bandwidth tiers are > even more grossly over buffered. > You can look at the netalyzr scatter plots in > http://gettys.wordpress.com/2010/12/06/whose-house-is-of-glasse-must-not-= throw-stones-at-another/ > > =E2=80=8BOh, I forgot to note: Netalyzr topped out at about 20M=E2=80=8Bbps= : most of why GPON looks good on those plots is just that the common lowest tier of service (at the time that data was taken) it can't easily detect the bloat. But if you perform other tests that don't have a bandwidth limit, the bloat is there. This reminds me I should ask Nick Weaver if he has more recent data... - Jim Now, if someone gives me real fiber to the home, with a real switch fabric > upstream, rather than gpon life might be somewhat better (if the switches > aren't themselves overbuffered.... But so far, it isn't. > - Jim > > > >> >> >> -- >> Mikael Abrahamsson email: swmike@swm.pp.se >> >> _______________________________________________ >> Bloat mailing list >> Bloat@lists.bufferbloat.net >> https://lists.bufferbloat.net/listinfo/bloat >> >> > --001a113356c6e7e37404f8315305 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable


On Tue= , Apr 29, 2014 at 12:44 PM, Jim Gettys <jg@freedesktop.org>= wrote:



On Tue, Apr 29, 2014 at 3:56 AM, Mikael Abrahamsson <<= a href=3D"mailto:swmike@swm.pp.se" target=3D"_blank">swmike@swm.pp.se&g= t; wrote:
On Tue, 29 Apr 2014, Fred Baker (fred) wrote:

Well, we could discuss international communications. I happen to be at Info= com in Toronto, VPN=E2=80=99d into Cisco San Jose, and did a ping to you:

Yes, but as soon as you hit the long distance network the latency is the sa= me regardless of access method. So while I agree that understanding the eff= ect of latency is important, it's no longer a meaningful way of selling= fiber access. If your last-mile is fiber instead of ADSL2+ won't impro= ve your long distance latency.

=E2=80=8BFIOS buf= ferbloat is a problem too.

Measured bufferbloat, symmetric 25/25 service = in New Jersey at my inlaw's house is 200ms (on the ethernet port of the= Actiontec router provided by Verizon). =C2=A0So latency under load is the = usual problem.

Why= would you think the GPON guys are any better in principle than cable or DS= L? =C2=A0Cable and DSL may be somewhat worse, just because it is older and = downward compatibility means that new modems on low bandwidth tiers are eve= n more grossly over buffered.


=E2=80= =8BOh, I forgot to note: Netalyzr topped out at about 20M=E2=80=8Bbps: most= of why
GPON looks good on those plots is just that the common lowest tier of servi= ce (at the time that data was taken) it can't easily detect the bloat. = But if you perform other tests that don't have a bandwidth limit, the b= loat is there.

This reminds me I should ask N= ick Weaver if he has more recent data...
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2= =A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 = =C2=A0 =C2=A0- Jim

Now, if someone gives me rea= l fiber to the home, with a real switch fabric upstream, rather than gpon l= ife might be somewhat better (if the switches aren't themselves overbuf= fered.... =C2=A0But so far, it isn't.
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 = =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2= =A0 =C2=A0 =C2=A0 - Jim

=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0=C2=A0


--
Mikael Abrahamsson =C2=A0 =C2=A0email: swmike@swm.pp.se

_______________= ________________________________
Bloat mailing list
Bloat@list= s.bufferbloat.net
= https://lists.bufferbloat.net/listinfo/bloat



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