From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ob0-x22d.google.com (mail-ob0-x22d.google.com [IPv6:2607:f8b0:4003:c01::22d]) (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 14AD821F1E7 for ; Tue, 7 Jan 2014 03:08:49 -0800 (PST) Received: by mail-ob0-f173.google.com with SMTP id gq1so19835542obb.32 for ; Tue, 07 Jan 2014 03:08:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type; bh=dyGgpivfO61MBWmwIys77MAuvsuCzZXdqSLDdW1I/2o=; b=UCVQoxkL73VcoCS96hJIrjFxOHNqiuRbajCUDOx4swTvFRHhJ1P9WTPi5ory7JFD+l a03a8P/CBNFaEwO7w85O9wGKH/6NIh4Fcv1+eGW/JwCu+IMA+YOcWI8S5VDHkjgmvB70 WuiEfZOH2JsNzLp7zkhLJVLTKk1JMk5HOeJc8PBH/kxj5PWhlA0gk0r50dDorawNkT2T oeFYSEaZQuwgLJNxTKqz4lDFhllfjODwx25DKkDHUxzoM+dcfDmksSRBmyx4j+AN8H5u wlm7HhqxHN9Vbm8VMZRTxlSjwuWtxPRDbakTk0kMfHCbznr/H9KfjjoP7qPGAFEtVRQ4 hk/Q== X-Received: by 10.60.67.105 with SMTP id m9mr568902oet.58.1389092927547; Tue, 07 Jan 2014 03:08:47 -0800 (PST) MIME-Version: 1.0 Received: by 10.182.38.194 with HTTP; Tue, 7 Jan 2014 03:08:27 -0800 (PST) In-Reply-To: References: <01558084-B7D8-448A-A4ED-CE36D18AAA97@gmail.com> <52C855B1.1040209@imap.cc> <52CA7CC3.2030203@imap.cc> <52CABC11.6040000@imap.cc> From: David Personette Date: Tue, 7 Jan 2014 06:08:27 -0500 Message-ID: To: Sebastian Moeller Content-Type: multipart/alternative; boundary=001a11c301fc81b6e604ef5f66c6 Cc: "cerowrt-devel@lists.bufferbloat.net" Subject: Re: [Cerowrt-devel] SQM Question #5: Link Layer Adaptation Overheads 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, 07 Jan 2014 11:08:52 -0000 X-List-Received-Date: Tue, 07 Jan 2014 11:08:52 -0000 --001a11c301fc81b6e604ef5f66c6 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable I'm in the US, but live in a relatively rural area. My only internet options are DSL and satellite. The local provider is Century Link (it used to be Sprint, but they sold their copper phone business off). I have the fastest service that they offer (based on distance from the DSLAM), 4 down / .5 up. I have had SmokePing monitoring my latency to the first hop outside my network for over a year now (I've been on CeroWRT the whole time). My baseline (no load) latency is 31ms. I used to have AQM throttling back to 80% of my already pathetic bandwidth. I would still regularly see periods lasting minutes to hours when latency would be 80 - 120ms. I only recently grokked what you were talking about with tc_stab since I got back from the holidays with the family, I set things up as you suggested for Fred (nfq_codel, "target 25ms" in advanced egress, ATM, per packet overhead 40, and set my SQM bandwidth limits to 95%). Since the 30th my "worst case" latency has been 41ms. Plus I get to use more of my actual bandwidth. I REALLY wish that I'd made the time to read your emails about setting up the ATM overhead earlier. Thank you. --=20 David P. On Mon, Jan 6, 2014 at 9:27 AM, Sebastian Moeller wrote: > Hi Fred, > > > On Jan 6, 2014, at 15:22 , Fred Stratton wrote: > > > The line rate is 11744/1022 kb/s, but changes moment to moment. SNR is > 12.1 decibel. I am using 11000/950 kb/s as settings. > > So 100 * 11000 / 11744 =3D 93.66% of downlink line rate and 100* = 950 > / 1022 =3D 92.95 % of uplink line rate; quite impressive given the common > wisdom of 85% :). > > > > I shall try your suggestion when there is something worth watching > live, to provide a valid comparison, which may not be before 21:30 CET on > Sunday. > > Oh, take your time, this is really not essential, butit would be = a > nice data point for figuring out how important the correct overhead > estimate really is in real life, theory being theory and all=E2=80=A6 > > Best Regards > Sebastian > > > > > On 06/01/14 14:12, Sebastian Moeller wrote: > >> Hi Fred, > >> > >> > >> On Jan 6, 2014, at 10:52 , Fred Stratton wrote: > >> > >>> I have been operating the latest build with 6relayd disabled. The > henet /48 I have been allocated is subnetted correctly, presumably by > dnsmasq. > >>> > >>> I adopted the suggestions to use nfq_codel and an egress target of > 25ms , with an overhead of 40 on a PPPoE connection. I chose to watch th= e > first 2 episodes of the 3 part third series of 'Sherlock', live on iPlaye= r, > and these streamed correctly and uninterrupted for 90 minutes. This was > not previously possible. (Quite whether they were up to the standard of > previous episodes is another matter.) > >>> > >>> I can watch iPlayer with little stutter whilst downloading Arch Linux > by torrent, downloading other files at the same time. > >>> > >>> So, for a relatively slow ADSL2+ line, the current build works well. > >> Out of curiosity, to what percentage of the "current line rate" > (you know the one reported by your modem) you shaped up- and downlink? An= d > in case you have too much time on your hand, how does the same feel with = an > overhead of 10 (to see how bad an overhead underestimate would feel for a > user), since you currently happen to have a quite sensitive subjective > latency evaluation system set up :)=E2=80=A6 > >> > >> Best Regards > >> Sebastian > >> > >>> > >>> On 06/01/14 03:29, Dave Taht wrote: > >>>> On Sat, Jan 4, 2014 at 10:40 AM, Fred Stratton > wrote: > >>>>> Link Names: > >>>>> > >>>>> For consistency, if ADSL is used as a portmanteau term, them VDSL > should be > >>>>> used as the equivalent for VDSL and VDSL2. > >>>>> > >>>>> CeroWRT has to decide whether it is an experimental build, or > something that > >>>>> will eventually be used in production, so these decisions can be ma= de > >>>>> consistently. > >>>> Well, what I was aiming for was for us to get the sqm scripts and gu= i > >>>> up to where they were better than the standard openwrt qos scripts a= nd > >>>> then push them up to openwrt to where they could be more widely > >>>> deployed. > >>>> > >>>> Aside from being able to dynamically assign priorities in the gui, w= e > >>>> are there. Except that nfq_codel is currently getting better result= s > >>>> than fq_codel at low bandwidths, and I'm tempted to pour all of > >>>> simple.qos into C. > >>>> > >>>> As for cero's future - certainly since all the snowden revelations > >>>> I've been going around saying that "friends don't let friends run > >>>> factory firmware". I would like a stable build of sqm and cerowrt to > >>>> emerge, and to then go off and work on improving wifi. Regrettably > >>>> what seems to be happening is more backwards than forwards on the > >>>> former, and ramping up on the ath9k and ath10k is taking more time > >>>> than I'd like, and it seems likely I'll be working on those primaril= y > >>>> on another platform and only eventually pushing the results out to > >>>> cero, mainline kernel > >>>> > >>>> So it's still at the "keep plugging away" point for sqm, ipv6, cero = in > >>>> general, with the stable release always just out of sight. > >>>> > >>>> Tackling the ipv6 problem is next on my agenda on cero, and getting = a > >>>> test suite going is next on my day job. > >>>> > >>>>> I concur with your ADSL setup suggestion as default. I have been > running the > >>>>> Sebastian Moeller ping script overnight to calculate ADSL overhead > for the > >>>>> last several days. After several hours of curve fitting using > Octave, an > >>>>> overhead result is displayed. This novel approach works well. > >>>> It would be nice to get to where we could autoconfigure a router usi= ng > >>>> tools like these with no human intervention. This includes bandwidth > >>>> estimation. > >>>> > >>>>> The overhead for the particular setup I use was 40 for PPPoE, and 1= 0 > for > >>>>> PPPoA. > >>>>> > >>>>> The default you suggest is a suitable starting point, I suggest. > >>>>> > >>>>> > >>>>> On 04/01/14 18:16, Rich Brown wrote: > >>>>>> QUESTION #5: I still don=E2=80=99t have any great answers for the = Link Layer > >>>>>> Adaptation overhead descriptions and recommendations. In an earlie= r > message, > >>>>>> (see > >>>>>> > https://lists.bufferbloat.net/pipermail/cerowrt-devel/2013-December/00191= 4.html > >>>>>> and following messages), Fred Stratton described the overheads > carried by > >>>>>> various options, and Sebastian Moeller also gave some useful advic= e. > >>>>>> > >>>>>> After looking at the options, I despair of giving people a clear > >>>>>> recommendation that would be optimal for their equipment. > Consequently, I > >>>>>> believe the best we can do is come up with =E2=80=9Cgood enough=E2= =80=9D > recommendations > >>>>>> that are not wrong, and still give decent performance. > >>>>>> > >>>>>> In this spirit, I have changed Draft #3 of the =E2=80=9CSetting up= SQM=E2=80=9D > page to > >>>>>> reflect this understanding. See > >>>>>> > http://www.bufferbloat.net/projects/cerowrt/wiki/Setting_up_AQM_for_CeroW= rt_310 > >>>>>> > >>>>>> ADSL/ATM link: Choose =E2=80=9CADSL/ATM", and set Per Pack= et > Overhead to > >>>>>> 40 > >>>>>> VDSL2 link: Choose =E2=80=9CVDSL=E2=80=9D, and set Per Pac= ket Overhead to 8 > >>>>>> Other kind of link (e.g., Cable, Fiber, Ethernet, other no= t > >>>>>> listed): Choose =E2=80=9CNone (default)=E2=80=9D, and set Per Pack= et Overhead to 0 > >>>>>> > >>>>>> NB: I have changed the first menu choice to =E2=80=9CADSL/ATM=E2= =80=9D and the > second to > >>>>>> =E2=80=9CVDSL=E2=80=9D in the description. I would ask that we cha= nge to GUI to > reflect > >>>>>> those names as well. This makes it far easier/less confusing to > talk about > >>>>>> the options. > >>>>>> > >>>>>> As always, I welcome help in setting out clear recommendations tha= t > work > >>>>>> well for the vast majority of people who try CeroWrt. Thanks. > >>>>>> > >>>>>> Rich > >>>>>> _______________________________________________ > >>>>>> Cerowrt-devel mailing list > >>>>>> Cerowrt-devel@lists.bufferbloat.net > >>>>>> https://lists.bufferbloat.net/listinfo/cerowrt-devel > >>>>> _______________________________________________ > >>>>> Cerowrt-devel mailing list > >>>>> Cerowrt-devel@lists.bufferbloat.net > >>>>> https://lists.bufferbloat.net/listinfo/cerowrt-devel > >>>> > >>> _______________________________________________ > >>> Cerowrt-devel mailing list > >>> Cerowrt-devel@lists.bufferbloat.net > >>> https://lists.bufferbloat.net/listinfo/cerowrt-devel > > > > _______________________________________________ > Cerowrt-devel mailing list > Cerowrt-devel@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/cerowrt-devel > --001a11c301fc81b6e604ef5f66c6 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
I'm in the US, but live in a relatively= rural area. My only internet options are DSL and satellite. The local prov= ider is Century Link (it used to be Sprint, but they sold their copper phon= e business off). I have the fastest service that they offer (based on dista= nce from the DSLAM), 4 down / .5 up.

I have had SmokePing monitoring my latency to the first hop outsi= de my network for over a year now (I've been on CeroWRT the whole time)= . My baseline (no load) latency is 31ms. I used to have AQM throttling back= to 80% of my already pathetic bandwidth. I would still regularly see perio= ds lasting minutes to hours when latency would be 80 - 120ms.

I only recently grokked what you were talking about with tc_stab = since I got back from the holidays with the family, I set things up as you = suggested for Fred (nfq_codel, "target 25ms" in advanced egress, = ATM, per packet overhead 40, and set my SQM bandwidth limits to 95%). Since= the 30th my "worst case" latency has been 41ms. Plus I get to us= e more of my actual bandwidth. I REALLY wish that I'd made the time to = read your emails about setting up the ATM overhead earlier.

Thank you.

-= -
David P.



On Mon, Jan 6, 2014 at 9:27 AM, Seba= stian Moeller <moeller0@gmx.de> wrote:
Hi Fred,


On Jan 6, 2014, at 15:22 , Fred Stratton <fredstratton@imap.cc> wrote= :

> The line rate is 11744/1022 kb/s, but changes moment to moment. SNR is= 12.1 decibel. =C2=A0I am using 11000/950 kb/s as settings.

=C2=A0 =C2=A0 =C2=A0 =C2=A0 So 100 * 11000 / 11744 =3D 93.66% of down= link line rate and 100* 950 / 1022 =3D 92.95 % of uplink line rate; quite i= mpressive given the common wisdom of 85% :).


> =C2=A0I shall try your suggestion when there is something worth watchi= ng live, to provide a valid comparison, which may not be before 21:30 CET o= n Sunday.

=C2=A0 =C2=A0 =C2=A0 =C2=A0 Oh, take your time, this is really not es= sential, butit would be a nice data point for figuring out how important th= e correct overhead estimate really is in real life, theory being theory and= all=E2=80=A6

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

>
> On 06/01/14 14:12, Sebastian Moeller wrote:
>> Hi Fred,
>>
>>
>> On Jan 6, 2014, at 10:52 , Fred Stratton <fredstratton@imap.cc&= gt; wrote:
>>
>>> I have been operating the latest build with 6relayd disabled. = The henet /48 I have been allocated is subnetted correctly, presumably by d= nsmasq.
>>>
>>> I adopted the suggestions to use nfq_codel and an egress targe= t of 25ms , with an overhead of 40 on a PPPoE connection. =C2=A0I chose to = watch the first 2 episodes of the 3 part third series of 'Sherlock'= , live on iPlayer, and these streamed correctly and uninterrupted for 90 mi= nutes. =C2=A0This was not previously possible. =C2=A0(Quite whether they we= re up to the standard of previous episodes is another matter.)
>>>
>>> I can watch iPlayer with little stutter whilst downloading Arc= h Linux by torrent, downloading other files at the same time.
>>>
>>> So, for a relatively slow ADSL2+ line, the current build works= well.
>> =C2=A0 =C2=A0 =C2=A0Out of curiosity, to what percentage of the &q= uot;current line rate" (you know the one reported by your modem) you s= haped up- and downlink? And in case you have too much time on your hand, ho= w does the same feel with an overhead of 10 (to see how bad an overhead und= erestimate would feel for a user), since you currently happen to have a qui= te sensitive subjective latency evaluation system set up :)=E2=80=A6
>>
>> Best Regards
>> =C2=A0 =C2=A0 =C2=A0Sebastian
>>
>>>
>>> On 06/01/14 03:29, Dave Taht wrote:
>>>> On Sat, Jan 4, 2014 at 10:40 AM, Fred Stratton <fredstr= atton@imap.cc> wrote:
>>>>> Link Names:
>>>>>
>>>>> For consistency, if ADSL is used as a portmanteau term= , them VDSL should be
>>>>> used as the equivalent for VDSL and VDSL2.
>>>>>
>>>>> CeroWRT has to decide whether it is an experimental bu= ild, or something that
>>>>> will eventually be used in production, so these decisi= ons can be made
>>>>> consistently.
>>>> Well, what I was aiming for was for us to get the sqm scri= pts and gui
>>>> up to where they were better than the standard openwrt qos= scripts and
>>>> then push them up to openwrt to where they could be more w= idely
>>>> deployed.
>>>>
>>>> Aside from being able to dynamically assign priorities in = the gui, we
>>>> are there. =C2=A0Except that nfq_codel is currently gettin= g better results
>>>> than fq_codel at low bandwidths, and I'm tempted to po= ur all of
>>>> simple.qos into C.
>>>>
>>>> As for cero's future - certainly since all the snowden= revelations
>>>> I've been going around saying that "friends don&#= 39;t let friends run
>>>> factory firmware". I would like a stable build of sqm= and cerowrt to
>>>> emerge, and to then go off and work on improving wifi. Reg= rettably
>>>> what seems to be happening is more backwards than forwards= on the
>>>> former, and ramping up on the ath9k and ath10k is taking m= ore time
>>>> than I'd like, and it seems likely I'll be working= on those primarily
>>>> on another platform and only eventually pushing the result= s out to
>>>> cero, mainline kernel
>>>>
>>>> So it's still at the "keep plugging away" po= int for sqm, ipv6, cero in
>>>> general, with the stable release always just out of sight.=
>>>>
>>>> Tackling the ipv6 problem is next on my agenda on cero, an= d getting a
>>>> test suite going is next on my day job.
>>>>
>>>>> I concur with your ADSL setup suggestion as default. I= have been running the
>>>>> Sebastian Moeller ping script overnight to calculate A= DSL overhead for the
>>>>> last several days. After several hours of curve fittin= g using Octave, an
>>>>> overhead result is displayed. This novel approach work= s well.
>>>> It would be nice to get to where we could autoconfigure a = router using
>>>> tools like these with no human intervention. This includes= bandwidth
>>>> estimation.
>>>>
>>>>> The overhead for the particular setup I use was 40 for= PPPoE, and 10 for
>>>>> PPPoA.
>>>>>
>>>>> The default you suggest is a suitable starting point, = I suggest.
>>>>>
>>>>>
>>>>> On 04/01/14 18:16, Rich Brown wrote:
>>>>>> QUESTION #5: I still don=E2=80=99t have any great = answers for the Link Layer
>>>>>> Adaptation overhead descriptions and recommendatio= ns. In an earlier message,
>>>>>> (see
>>>>>> https://lists.b= ufferbloat.net/pipermail/cerowrt-devel/2013-December/001914.html
>>>>>> and following messages), Fred Stratton described t= he overheads carried by
>>>>>> various options, and Sebastian Moeller also gave s= ome useful advice.
>>>>>>
>>>>>> After looking at the options, I despair of giving = people a clear
>>>>>> recommendation that would be optimal for their equ= ipment. Consequently, I
>>>>>> believe the best we can do is come up with =E2=80= =9Cgood enough=E2=80=9D recommendations
>>>>>> that are not wrong, and still give decent performa= nce.
>>>>>>
>>>>>> In this spirit, I have changed Draft #3 of the =E2= =80=9CSetting up SQM=E2=80=9D page to
>>>>>> reflect this understanding. See
>>>>>> http://www.buff= erbloat.net/projects/cerowrt/wiki/Setting_up_AQM_for_CeroWrt_310
>>>>>>
>>>>>> =C2=A0 =C2=A0 =C2=A0 =C2=A0 ADSL/ATM link: Choose = =E2=80=9CADSL/ATM", and set Per Packet Overhead to
>>>>>> 40
>>>>>> =C2=A0 =C2=A0 =C2=A0 =C2=A0 VDSL2 link: Choose =E2= =80=9CVDSL=E2=80=9D, and set Per Packet Overhead to 8
>>>>>> =C2=A0 =C2=A0 =C2=A0 =C2=A0 Other kind of link (e.= g., Cable, Fiber, Ethernet, other not
>>>>>> listed): Choose =E2=80=9CNone (default)=E2=80=9D, = and set Per Packet Overhead to 0
>>>>>>
>>>>>> NB: I have changed the first menu choice to =E2=80= =9CADSL/ATM=E2=80=9D and the second to
>>>>>> =E2=80=9CVDSL=E2=80=9D in the description. I would= ask that we change to GUI to reflect
>>>>>> those names as well. This makes it far easier/less= confusing to talk about
>>>>>> the options.
>>>>>>
>>>>>> As always, I welcome help in setting out clear rec= ommendations that work
>>>>>> well for the vast majority of people who try CeroW= rt. Thanks.
>>>>>>
>>>>>> Rich
>>>>>> _______________________________________________ >>>>>> Cerowrt-devel mailing list
>>>>>> Cerowrt-devel@lists.bufferbloat.net
>>>>>> https://lists.bufferbloat.net/listinfo/cer= owrt-devel
>>>>> _______________________________________________
>>>>> Cerowrt-devel mailing list
>>>>> Cerowrt-devel@lists.bufferbloat.net
>>>>> https://lists.bufferbloat.net/listinfo/cerowrt= -devel
>>>>
>>> _______________________________________________
>>> Cerowrt-devel mailing list
>>> Cerowrt= -devel@lists.bufferbloat.net
>>> https://lists.bufferbloat.net/listinfo/cerowrt-devel
>

_______________________________________________
Cerowrt-devel mailing list
Cerowrt-devel@lists.= bufferbloat.net
https://lists.bufferbloat.net/listinfo/cerowrt-devel

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