[Cerowrt-devel] [Bloat] DOCSIS 3+ recommendation?

MUSCARIELLO Luca IMT/OLN luca.muscariello at orange.com
Fri Mar 20 10:05:36 EDT 2015

I don't know.
 From my personal experience, I feel like the "expert" wearing ties
watch the speed meter and the needle moving across the red bar.

We just need to be sure about the colors: when the latency goes into the 
crazy region
the needle has to cross a RED bar! GREEN is good, RED is bad (exceptions 
apply in case of daltonism).

Maybe I'm oversimplifying... but not that much...

If your solution is to educate people with ties on Internet congestion 
control I feel bad...


On 03/20/2015 02:31 PM, David P. Reed wrote:
> The mystery in most users' minds is that ping at a time when there is 
> no load does tell them anything at all about why the network 
> connection will such when their kid is uploading to youtube.
> So giving them ping time is meaningless.
> I think most network engineers think ping time is a useful measure of 
> a badly bufferbloated system. It is not.
> The only measure is ping time under maximum load of raw packets.
> And that requires a way to test maximum load rtt.
> There is no problem with that ... other than that to understand why 
> and how that is relevant you have to understand Internet congestion 
> control.
> Having had to testify before CRTC about this, I learned that most 
> access providers (the Canadian ones) claim that such measurements are 
> never made as a measure of quality, and that you can calculate 
> expected latency by using Little's lemma from average throughput. And 
> that dropped packets are the right measure of quality of service.
> Ookla ping time  is useless in a context where even the "experts" 
> wearing ties from the top grossing Internet firms are so confused. And 
> maybe deliberately misleading on purpose... they had to be forced to 
> provide any data they had about  congestion in their networks by a 
> ruling during the proceeding and then responded that they had no data 
> - they never measured queueing delay and disputed that it mattered. 
> The proper measure of congestion was throughput.
> I kid you not.
> So Ookla ping time is useless against such public ignorance.
> That's completely wrong for
> On Mar 20, 2015, MUSCARIELLO Luca IMT/OLN 
> <luca.muscariello at orange.com> wrote:
>     I agree. Having that ping included in Ookla would help a lot more
>     Luca
>     On 03/20/2015 12:18 AM, Greg White wrote:
>         Netalyzr is great for network geeks, hardly consumer-friendly,
>         and even so
>         the "network buffer measurements" part is buried in 150 other
>         statistics.
>         Why couldn't Ookla* add a simultaneous "ping" test to their
>         throughput
>         test? When was the last time someone leaned on them?
>         *I realize not everyone likes the Ookla tool, but it is
>         popular and about
>         as "sexy" as you are going to get with a network performance tool.
>         -Greg
>         On 3/19/15, 2:29 PM, "dpreed at reed.com" <dpreed at reed.com> wrote:
>             I do think engineers operating networks get it, and that
>             Comcast's
>             engineers really get it, as I clarified in my followup note.
>             The issue is indeed prioritization of investment,
>             engineering resources
>             and management attention. The teams at Comcast in the
>             engineering side
>             have been the leaders in "bufferbloat minimizing" work,
>             and I think they
>             should get more recognition for that.
>             I disagree a little bit about not having a test that shows
>             the issue, and
>             the value the test would have in demonstrating the issue
>             to users.
>             Netalyzer has been doing an amazing job on this since
>             before the
>             bufferbloat term was invented. Every time I've talked
>             about this issue
>             I've suggested running Netalyzer, so I have a personal set
>             of comments
>             from people all over the world who run Netalyzer on their
>             home networks,
>             on hotel networks, etc.
>             When I have brought up these measurements from Netalyzr
>             (which are not
>             aimed at showing the problem as users experience) I observe an
>             interesting reaction from many industry insiders: the
>             results are not
>             "sexy enough for stupid users" and also "no one will care".
>             I think the reaction characterizes the problem correctly -
>             but the second
>             part is the most serious objection. People don't need a
>             measurement
>             tool, they need to know that this is why their home
>             network sucks
>             sometimes.
>             On Thursday, March 19, 2015 3:58pm, "Livingood, Jason"
>             <Jason_Livingood at cable.comcast.com> said:
>                 On 3/19/15, 1:11 PM, "Dave Taht" <dave.taht at gmail.com>
>                 wrote:
>                     On Thu, Mar 19, 2015 at 6:53 AM, <dpreed at reed.com>
>                     wrote:
>                         How many years has it been since Comcast said
>                         they were going to fix
>                         bufferbloat in their network within a year?
>                 I¹m not sure anyone ever said it¹d take a year. If
>                 someone did (even if
>                 it
>                 was me) then it was in the days when the problem
>                 appeared less
>                 complicated
>                 than it is and I apologize for that. Let¹s face it -
>                 the problem is
>                 complex and the software that has to be fixed is
>                 everywhere. As I said
>                 about IPv6: if it were easy, it¹d be done by now. ;-)
>                         It's almost as if the cable companies don't
>                         want OTT video or
>                         simultaneous FTP and interactive gaming to
>                         work. Of course not. They'd
>                         never do that.
>                 Sorry, but that seems a bit unfair. It flies in the
>                 face of what we have
>                 done and are doing. We¹ve underwritten some of Dave¹s
>                 work, we got
>                 CableLabs to underwrite AQM work, and I personally
>                 pushed like heck to
>                 get
>                 AQM built into the default D3.1 spec (had CTO-level
>                 awareness & support,
>                 and was due to Greg White¹s work at CableLabs). We are
>                 starting to field
>                 test D3.1 gear now, by the way. We made some bad bets
>                 too, such as
>                 trying
>                 to underwrite an OpenWRT-related program with ISC, but
>                 not every tactic
>                 will always be a winner.
>                 As for existing D3.0 gear, it¹s not for lack of
>                 trying. Has any DOCSIS
>                 network of any scale in the world solved it? If so, I
>                 have something to
>                 use to learn from and apply here at Comcast - and I¹d
>                 **love** an
>                 introduction to someone who has so I can get this info.
>                 But usually there are rational explanations for why
>                 something is still
>                 not
>                 done. One of them is that the at-scale operational
>                 issues are more
>                 complicated that some people realize. And there is
>                 always a case of
>                 prioritization - meaning things like running out of
>                 IPv4 addresses and
>                 not
>                 having service trump more subtle things like buffer
>                 bloat (and the
>                 effort
>                 to get vendors to support v6 has been tremendous).
>                     I do understand there are strong forces against
>                     us, especially in the
>                     USA.
>                 I¹m not sure there are any forces against this issue.
>                 It¹s more a
>                 question
>                 of awareness - it is not apparent it is more urgent
>                 than other work in
>                 everyone¹s backlog. For example, the number of ISP
>                 customers even aware
>                 of
>                 buffer bloat is probably 0.001%; if customers aren¹t
>                 asking for it, the
>                 product managers have a tough time arguing to
>                 prioritize buffer bloat
>                 work
>                 over new feature X or Y.
>                 One suggestion I have made to increase awareness is
>                 that there be a
>                 nice,
>                 web-based, consumer-friendly latency under load /
>                 bloat test that you
>                 could get people to run as they do speed tests today.
>                 (If someone thinks
>                 they can actually deliver this, I will try to fund it
>                 - ping me
>                 off-list.)
>                 I also think a better job can be done explaining
>                 buffer bloat - it¹s
>                 hard
>                 to make an Œelevator pitch¹ about it.
>                 It reminds me a bit of IPv6 several years ago. Rather
>                 than saying in
>                 essence Œyou operators are dummies¹ for not already
>                 fixing this, maybe
>                 assume the engineers all Œget it¹ and what to do it.
>                 Because we really
>                 do
>                 get it and want to do something about it. Then ask
>                 those operators what
>                 they need to convince their leadership and their
>                 suppliers and product
>                 managers and whomever else that it needs to be
>                 resourced more
>                 effectively
>                 (see above for example).
>                 We¹re at least part of the way there in DOCSIS
>                 networks. It is in D3.1
>                 by
>                 default, and we¹re starting trials now. And probably
>                 within 18-24 months
>                 we won¹t buy any DOCSIS CPE that is not 3.1.
>                 The question for me is how and when to address it in
>                 DOCSIS 3.0.
>                 - Jason
> -- Sent with *K-@ Mail 
> <https://play.google.com/store/apps/details?id=com.onegravity.k10.pro2>* 
> - the evolution of emailing. 

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