From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-x235.google.com (mail-oi0-x235.google.com [IPv6:2607:f8b0:4003:c06::235]) (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 CBD093BA8E for ; Tue, 16 Jan 2018 14:36:41 -0500 (EST) Received: by mail-oi0-x235.google.com with SMTP id u83so11419287oie.7 for ; Tue, 16 Jan 2018 11:36:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ariekanarie-nl.20150623.gappssmtp.com; s=20150623; h=mime-version:sender:from:date:message-id:subject:to; bh=U1ANQgJdLaS4ANXSY+v6oIT3N86wKTAHlHAEAXAfx7w=; b=17BSmoE4Yy3bAP46IyJJZ3VmsbMu8mqwgH6TSSpAbHuW3MXVDixHQ6pm8f02ZgnsOI RfxMnw4hUbaVKH7FGcw6/7PdYivbhHtm1rLCFTafh1r8GYA9uPOnqITAwDvpA6bafFzh hPaZGGc1DH6KWmiMf45yqilImoGplJl6+y8SmUL+R5q6RdmM1iz5K7eInUbRMGW6vxW+ 9GqJiic5VHTUkInGOGGoeyWE+JP6d3ix4lsr+ULmaYymaChGh89IPnY9ZbklqXvDRUl3 hdeDtgrR1cKir2eiWOqUQBHFy6dPdIy+Bkq0XqaRUaRkv9795AvGZLU25RmDkg7jLnwH jKnA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:sender:from:date:message-id:subject :to; bh=U1ANQgJdLaS4ANXSY+v6oIT3N86wKTAHlHAEAXAfx7w=; b=tXcDzal6zjTY2bp34rHSO1pSfty+lU5mcJRXXgpx9FKEUnAr13kmxCdPOe+Pxb5CHJ 0DxGEgp29V9r5hCILFYWF5pAH5Pnm0RDtEbiu4EYufoq1iBxiNDd54iSZEl77Io87hdP 5GhBzdFbz1TbIKwtdQFAE1/6xfICdCH00EyoYWtimeb5+CF5LtktMJ8vRV6ZyToj0GLl Ejh8+75mH8/HAvj5ClEpvlWWjwXDB4XVw5C8WDZ3+fyb2jhm2SURZpuZpvNUBaID4u7h of/FVqLjZqNLuiUkXfwV8PtxguCANyGw3xOqlLXURvo2j+XRiU9vs5gKsQ01HG+3yBGO e/QQ== X-Gm-Message-State: AKGB3mJhVflNp8n9SlS4Er522fQnHP3JnqtcWd6bwMU7l/s2nPynjbeS axc8PvUO4FbKGEWk6d64Fxf+E079rIG2D5ArvHkO0iIm X-Google-Smtp-Source: ACJfBouE8nU1sHm5Vr7z0CBHm9jUupDK2FoWoSzAwJxewyoJF3Iodv3dxLWlaDNaJRdUntg4dKfFV1DUCrgPgKy83bo= X-Received: by 10.202.178.196 with SMTP id b187mr19167640oif.234.1516131398559; Tue, 16 Jan 2018 11:36:38 -0800 (PST) MIME-Version: 1.0 Sender: arie@ariekanarie.nl Received: by 10.74.2.77 with HTTP; Tue, 16 Jan 2018 11:36:37 -0800 (PST) X-Originating-IP: [178.85.156.201] From: Arie Date: Tue, 16 Jan 2018 20:36:37 +0100 X-Google-Sender-Auth: nfYKQl2Z48maS_WHnUho4wyAOco Message-ID: To: bloat@lists.bufferbloat.net Content-Type: multipart/alternative; boundary="001a113cdff271c4840562e9d9cd" Subject: [Bloat] Curious bufferbloat on DOCSIS connection with many downloads 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: Tue, 16 Jan 2018 19:36:42 -0000 --001a113cdff271c4840562e9d9cd Content-Type: text/plain; charset="UTF-8" Recently I accidentally discovered something quite odd about my home DOCSIS connection (shaped with cake) while running a flent rrul test. During the flent rrul test, another machine in my home had started a Steam game update, this opened somewhere between 8-12 connections and saturated my downstream. The interesting part was the resulting rrul graph, showing perfect latency control during the test, but 100-150ms of bufferbloat at the very start and end of the rrul graph (when rrul is idle, just pinging). Instead of a Steam download I started an iperf3 client on a remote machine that opened 16 connections to a LAN machine. Same behavior as the Steam download. At first I thought this was a bug with cake, but no matter how I tuned cake (limiting my 400/40 connection to 50/20 for example), the behavior was similar. I tried fq_codel+htb, and got similar results to cake, high latency before the rrul test kicked off, great latency while rrul was doing its up and downloads. So I swapped out my self-compile LEDE router with an Edgerouter ER-X with both stock and LEDE firmware, both with fq_codel and cake (on both stock and LEDE firmware). Same results. Even without any SQM active, the rrul test still improved the latency of my connection when it's also downloading from 8+ connections at the same time. I managed to take the flent rrul test out of the equation by starting a hping3 "flood" to the hop next of my cable modem. hping3 -2 -d 0 -s 10080 -k -p 80 -i u100 first-hop-or-ISP-gateway-goes-here > This also fixed the latency while many downloads were running by sending about 300KB/s of empty UDP packets to some unresponsive port on my ISPs local gateway. I'm puzzled by this result, somehow sending 300KB/s of empty packets upstream drastically improves the latency of my connection when it's receiving many downloads. Equipment used: Cisco EPC3212 cable modem (8x4 EuroDOCSIS 3.0) Linksys WRT1900ACS router with LEDE Ubiquiti Edgerouter ER-X with both EdgeOS (stock) and LEDE --001a113cdff271c4840562e9d9cd Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Recently I accidentally discovered something quite odd abo= ut my home DOCSIS connection (shaped with cake) while running a flent rrul = test.
During the flent rrul test, another machine in my home had starte= d a Steam game update, this opened somewhere between 8-12 connections and s= aturated my downstream.

The interesting part was t= he resulting rrul graph, showing perfect latency control during the test, b= ut 100-150ms of bufferbloat at the very start and end of the rrul graph (wh= en rrul is idle, just pinging).

Instead of a Steam= download I started an iperf3 client on a remote machine that opened 16 con= nections to a LAN machine. Same behavior as the Steam download.
<= br>
At first I thought this was a bug with cake, but no matter ho= w I tuned cake (limiting my 400/40 connection to 50/20 for example), the be= havior was similar.
I tried fq_codel+htb, and got similar results= to cake, high latency before the rrul test kicked off, great latency while= rrul was doing its up and downloads.

So I swapped= out my self-compile LEDE router with an Edgerouter ER-X with both stock an= d LEDE firmware, both with fq_codel and cake (on both stock and LEDE firmwa= re). Same results.
Even without any SQM active, the rrul test sti= ll improved the latency of my connection when it's also downloading fro= m 8+ connections at the same time.

I managed to ta= ke the flent rrul test out of the equation by starting a hping3 "flood= " to the hop next of my cable modem.=C2=A0

hping3 -2 -d 0 -s 10080 -k -p 80= -i u100 first-hop-or-ISP-gateway-goes-here
=C2=A0
This also fixed the latency while many downloads were running by sen= ding about 300KB/s of empty UDP packets to some unresponsive port on my ISP= s local gateway.

I'm puzzled by this result, s= omehow sending 300KB/s of empty packets upstream drastically improves the l= atency of my connection when it's receiving many downloads.
<= br>
Equipment used:
Cisco EPC3212 cable modem (8x4 Euro= DOCSIS 3.0)
Linksys WRT1900ACS router with LEDE
Ubiquit= i Edgerouter ER-X with both EdgeOS (stock) and LEDE



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