From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ee0-f49.google.com (mail-ee0-f49.google.com [74.125.83.49]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id 64B7C200666 for ; Sat, 9 Feb 2013 10:33:13 -0800 (PST) Received: by mail-ee0-f49.google.com with SMTP id d4so2534933eek.8 for ; Sat, 09 Feb 2013 10:33:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=x-received:mime-version:sender:in-reply-to:references:from:date :x-google-sender-auth:message-id:subject:to:content-type; bh=+MYyegVI/Mak6EFPx/2CLlUp2Uei+XeZq1Cf7riel/E=; b=B/Xtrp3vbhTl/dfeCILVW3lFWTQ37HaKXo2BnoSj+Zhz9xoFjMtRri85PHyAyp82Fh CjIpIiLZw/L7e+AwSy5o2UmkRgYZAbF+zRjMqtksxOMLuSUx2X5/x2AfFZMlxcelvrwY A9STMN4za2QwHWjr9FK4Y2H1eLXMqD5JTNTZr95AUUYhZmFt5ns0C91Qs+4wtMAjJUtY rYf5JCEZSZX6ZvgPMFxi9/U8jrpaxck27ogBGI4iUAH2WU6+9Vq5eMD8mIXVSLuJhu4z CmYzQAzftRvmUoLcsLAmSnahgpKg6Z+GaklxHhs08qyUHbySQXYjq7vWIanmjeFamU3n DvaA== X-Received: by 10.14.174.73 with SMTP id w49mr30293803eel.17.1360434791198; Sat, 09 Feb 2013 10:33:11 -0800 (PST) MIME-Version: 1.0 Sender: jeroen.balduyck@gmail.com Received: by 10.14.209.193 with HTTP; Sat, 9 Feb 2013 10:32:40 -0800 (PST) In-Reply-To: References: From: Forums1000 Date: Sat, 9 Feb 2013 19:32:40 +0100 X-Google-Sender-Auth: gIrP5Z4g0CjCmWB1LWqDTwOj8D8 Message-ID: To: bloat@lists.bufferbloat.net Content-Type: multipart/alternative; boundary=047d7b6042f0782f0504d54ee8d1 Subject: [Bloat] I am unable to pinpoint the source of bufferbloat X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 09 Feb 2013 18:33:14 -0000 --047d7b6042f0782f0504d54ee8d1 Content-Type: text/plain; charset=ISO-8859-1 The newer modem supports the bonding of more download channels (8 vs. 4 for the 6120) and is also used in conjunction with telephony (whereas I have a pure Internet subscription without telephony). Anyway, all of that should not matter as you also indicate: both can handle the respective up- and download speeds with ease. Yes, both she and I have the same subscription (minus the telephony): 60 Mb down and 4 Mb up. We also only live 25 kilometres apart (small country:-)) The uplink speed is mostly consistent around 3.76 megabit. I've never caught our cable company going lower than 3.50 megabit in the upload direction and I've done a lot of speedtests. The only limit I have been able to observe is in the download direction when their network is really busy. I guess I will have to venture into traffic shaping. (I'll probably loose a lot of sleep setting this up lol). Is there any way to determine the buffer size reliably? On Sat, Feb 9, 2013 at 7:15 PM, Jonathan Morton wrote: > Latency caused by bufferbloat always appears at the bottleneck device. > Usually that is the modem, and you've given no alternative that it could > plausibly be. The modems you mention are slightly different model numbers, > but that can hide substantial differences in internal configuration. > > For a typical drop-tail queue, the induced latency under load is the size > of the buffer divided by the speed of the link draining it. Assuming both > modems have a 4Mbit uplink, 550ms is consistent with a 256KB buffer, and > 220ms is consistent with a 48KB buffer - neither of which would seem > excessively large to a modem builder who hasn't heard of bufferbloat. > However with a shared cable infrastructure, it is possible that the uplink > is constrained by other users on the same segment, which will skew this > calculation. > > To cure it without modifying the modem, you need to move the bottleneck to > a point where you can control the buffer. You do this by introducing > traffic shaping at slightly below the advertised modem uplink speed on one > of your own machines and directing all upstream traffic through it. > > - Jonathan Morton > On Feb 9, 2013 7:27 PM, "Forums1000" wrote: > >> Hi Jonathan and Dave >> >> My entire LAN-network is gigabit. My cable subscription is 60 megabit >> down and 4 megabit up. >> Now, both my routers' WAN-port and the cable modems' LAN port are also >> gigabit. The router can route LAN to WAN and the other way around (with NAT >> and connection tracking enabled) in excess of 100 megabit. >> >> Now my cable modem is a Motorola Surfboard SV6120E and hers is a Motorola >> Surfboard CV6181E. My upload lag is 550ms and hers is only 220ms. Moreover, >> at her place there are Powerplugs in the path limiting her download to 30 >> megabit instead of 60 megabit. Yet, the upload lag is much lower than mine. >> There, it also did not matter where I ran Natalyzr, the result was always >> 220ms of bufferbload. >> >> Could this still be only the modem? >> >> >> On Sat, Feb 9, 2013 at 10:52 AM, Forums1000 wrote: >> >>> Hi everyone, >>> >>> Can anyone give some tips on how to diagnose the sources of bufferbloat? >>> According to the Netalyzr test at http://netalyzr.icsi.berkeley.edu/, I >>> have 550ms of upload bufferbloat. I tried all kinds of stuff on my Windows >>> 7 laptop: >>> >>> - For the Intel(R) 82567LF Gigabit Network Connection, I put receive and >>> transmit buffers to the lowest value of 80 (80 bytes? 80 packets? I don't >>> know). I also disabled interrupt moderation. >>> Result? Still 550ms. >>> - Then I connected my laptop directly to my cable modem, bypassing my >>> Mikrotik 450G router. Result? Still 550ms of bufferbloat. >>> - Then I put a 100 megabit switch between the cable modem an the laptop >>> (as both cable modem and Intel NIC are gigabit). Result? Still 550ms of >>> upload bufferbloat. >>> >>> I'm out of ideas now. It seems I can't do anything at all to lower >>> bufferbloat. Or the Netalyzr test is broken?:-) >>> >>> many thanks for your advice, >>> Jeroen >>> >>> >> >> _______________________________________________ >> Bloat mailing list >> Bloat@lists.bufferbloat.net >> https://lists.bufferbloat.net/listinfo/bloat >> >> --047d7b6042f0782f0504d54ee8d1 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable The newer modem supports the bonding of more download channels (8 vs. 4 for= the 6120) and is also used in conjunction with telephony (whereas I have a= pure Internet subscription without telephony). Anyway, all of that should = not matter as you also indicate: both can handle the respective up- and dow= nload speeds with ease.

Yes, both she and I have the same subscription (minus the telephony): 6= 0 Mb down and 4 Mb up. We also only live 25 kilometres apart (small country= :-))
The uplink speed is mostly consistent around 3.76 megabit. I've= never caught our cable company going lower than 3.50 megabit in the upload= direction and I've done a lot of speedtests. The only limit I have bee= n able to observe is in the download direction when their network is really= busy.

I guess I will have to venture into traffic shaping. (I'll probably= loose a lot of sleep setting this up lol). Is there any way to determine t= he buffer size reliably?

On Sat, Feb 9, 2= 013 at 7:15 PM, Jonathan Morton <chromatix99@gmail.com> = wrote:

Latency caused by bufferbloat always appe= ars at the bottleneck device. Usually that is the modem, and you've giv= en no alternative that it could plausibly be. The modems you mention are sl= ightly different model numbers, but that can hide substantial differences i= n internal configuration.

For a typical drop-tail queue, the induced latency under load is the siz= e of the buffer divided by the speed of the link draining it. Assuming both= modems have a 4Mbit uplink, 550ms is consistent with a 256KB buffer, and 2= 20ms is consistent with a 48KB buffer - neither of which would seem excessi= vely large to a modem builder who hasn't heard of bufferbloat. However = with a shared cable infrastructure, it is possible that the uplink is const= rained by other users on the same segment, which will skew this calculation= .

To cure it without modifying the modem, you need to move the bottleneck = to a point where you can control the buffer. You do this by introducing tra= ffic shaping at slightly below the advertised modem uplink speed on one of = your own machines and directing all upstream traffic through it.

- Jonathan Morton

On Feb 9, 2= 013 7:27 PM, "Forums1000" <forums1000@gmail.com> wrote:
Hi Jonathan and Dave

My entire LAN-network is gigabit. My cable subs= cription is 60 megabit down and 4 megabit up.
Now, both my routers'= WAN-port and the cable modems' LAN port are also gigabit. The router c= an route LAN to WAN and the other way around (with NAT and connection track= ing enabled) in excess of 100 megabit.

Now my cable modem is a Motorola Surfboard SV6120E and hers is a Motoro= la Surfboard CV6181E. My upload lag is 550ms and hers is only 220ms. Moreov= er, at her place there are Powerplugs in the path limiting her download to = 30 megabit instead of 60 megabit. Yet, the upload lag is much lower than mi= ne. There, it also did not matter where I ran Natalyzr, the result was alwa= ys 220ms of bufferbload.

Could this still be only the modem?


On Sat, Feb 9, 2013 at 10:52 AM, Forums1000 <forums1000@gmail.com> wrote:
Hi everyone,

Can anyone give some tip= s on how to diagnose the sources of bufferbloat? According to the Netalyzr = test at ht= tp://netalyzr.icsi.berkeley.edu/, I have 550ms of upload bufferbloat. I= tried all kinds of stuff on my Windows 7 laptop:

- For the Intel(R) 82567LF Gigabit Network Connection, I put receive an= d transmit buffers to the lowest value of 80 (80 bytes? 80 packets? I don&#= 39;t know). I also disabled interrupt moderation.
Result? Still 550ms.<= br> - Then I connected my laptop directly to my cable modem, bypassing my Mikro= tik 450G router. Result? Still 550ms of bufferbloat.
- Then I put a 100= megabit switch between the cable modem an the laptop (as both cable modem = and Intel NIC are gigabit). Result? Still 550ms of upload bufferbloat.

I'm out of ideas now. It seems I can't do anything at all to lo= wer bufferbloat. Or the Netalyzr test is broken?:-)

many thanks for = your advice,
Jeroen



_________________________________________= ______
Bloat mailing list
Bloat@list= s.bufferbloat.net
= https://lists.bufferbloat.net/listinfo/bloat


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