From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.gmx.net (mout.gmx.net [212.227.15.18]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mout.gmx.net", Issuer "TeleSec ServerPass DE-1" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id AD7CA21F56C for ; Sat, 24 Oct 2015 10:24:38 -0700 (PDT) Received: from hms-beagle.home.lan ([217.237.68.126]) by mail.gmx.com (mrgmx002) with ESMTPSA (Nemesis) id 0MF4eJ-1ZiYRd0ktn-00GGde; Sat, 24 Oct 2015 19:24:34 +0200 Mime-Version: 1.0 (Mac OS X Mail 7.3 \(1878.6\)) Content-Type: text/plain; charset=windows-1252 From: Sebastian Moeller X-Priority: 3 In-Reply-To: <931be41d-68b7-4fea-9d4e-14bf1636e9bc@reed.com> Date: Sat, 24 Oct 2015 19:24:54 +0200 Content-Transfer-Encoding: quoted-printable Message-Id: <2DE7C829-5C11-4B9A-B8FD-10029918A7FA@gmx.de> References: <562A5BE5.6010101@gmail.com> <12883.1445625688@sandelman.ca> <562A9611.4050403@gmail.com> <931be41d-68b7-4fea-9d4e-14bf1636e9bc@reed.com> To: "David P. Reed" X-Mailer: Apple Mail (2.1878.6) X-Provags-ID: V03:K0:+HwdWlm+Zvkuv80h1cUePU38U1WU/K7ZwDv7v6v0Zt24BjnWOSi 9zRS19pcxfJP3LH3IYXQwBvOdjEi7C3lgpRxPXbPnuxDBgmMZQeNsn6Vrf4tllEhEr2t9wE 2JypdXQsE1TqqbQd7X6Rlpec8SnJlOZjfwRg4gKpLK9dL+Fj3H5QCFgkrF1rK/5c6NCcGSA 5JIwN172duhu+EO00Dlvg== X-UI-Out-Filterresults: notjunk:1;V01:K0:OV0zFRFkMz8=:SmptmzV8hgn4YKgp4icsqA jsJlMT1jvgnn95bDKYXPRhO5FeVeT9a0+WdlJMSh+nqUC4MegUMXTe6uVjkxb4CJsXJgNv2zz I5S2Clo+BB1X7dklRXa86DVff+S/tNujGbnN1E8jxfvlp/FRwZG2gUaiOy5gF403xI+zH5bfy S3LTtFGtPxg6XEYnQVdMOYFBeb3NzO3Ft7exTZ9lnmrp9N5vvriD9nNvJBEjyLk53LRPKWmbe 2HZj8PIOKSnJL/dZrznqNuRSXyqX421lFx5mGiUBSlYtZe6aXLeF5KgaUJIgKktGdg3+IZEzf HY0t27SDd14f3Co2Q1gxTD6tY+cO3sRnJQ5TtQApK7GuKJ6AEnySEtMToxdvEwhnBqYKvSIY3 tjIeyOZh8Kb2OWORo1+XpqIP7Jnr9QHHwUrMqte8U7ye4sdoK1aXh8U4Iki3drNeH/x8Qw1eJ mKoZjDVCUSouC9JTxcKFP4/8edTvH3M9DM9NrIX8KINZdp5/7uSDXlYqqomVIEghwGxhHu05P JP0NM4UcH9tuSdyvnoIAUNkxKnTLBmkSH9ZRzsP4fb9DRpHYovKOvaSNtuWZdhGfs+AX0RFWz EfvC9qtlWOmddG/T5iu1iTsHsYwVDR+sEN3wNTe3l4taeTMp/HLn8pzMQej0cw0INVP+/slv1 pRsGpJGqDELEVqknKEDQTRkO9pM+z2QHFwotoViTGTIuAFxtfK/u9M/9nxq8qK7h6WbTNFmUf /Syp/XOMqn2BPDVNl49MycPBP0pRff6B7OdPQzlzcHoByi4+J18FmqF12aGJYPVMJc78qxm+s +ww0d+X Cc: cerowrt-devel@lists.bufferbloat.net Subject: Re: [Cerowrt-devel] Problems testing sqm 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: Sat, 24 Oct 2015 17:25:01 -0000 Hi David, On Oct 24, 2015, at 18:34 , David P. Reed wrote: > Not trying to haggle. Sorry, I was a bit to grumpy for unrelated reasons. > Just pointing out that this test configuration has a very short RTT. = maybe too short for our SQM to adjust to. That could be, but I believe people have tested fq_codel and sqm = with similar setups and generally got dozens of milliseconds induced = delay, not multiple seconds. So sure sqm might not for the best thing = but it should deliver a reasonable compromise. Now, I believe Toke has a = test bed where he can vary the transmission delay so he might know = already whether sqm has issues with 1GE lans. Best Regards Sebastian >=20 > On Oct 24, 2015, Sebastian Moeller wrote: > Hi David, >=20 > On Oct 24, 2015, at 00:53 , David P. Reed wrote: >=20 > In particular, the DUT should probably have no more than 2 packets of = outbound queueing given the very small RTT. 2xRTT is the most buffering = you want in the loop. >=20 > Let=92s not haggle about the precise amount of queueing we deem = acceptable, as long as we all agree that >=3D 2 seconds is simply not = acceptable ;) (the default sqm will approximately limit the latency = under load increase (LULI) to roughly twice the target or typically 10 = ms; note that this LULI only applies to unrelated flows). The exact = number of queued packets seems to correlate with the beefiness of the = DUT, the beefier the fewer packets should work, wimpier devices might = need to batch some processing up, resulting in higher LULI=85 >=20 > Best Regards > Sebastian >=20 >=20 > On Oct 23, 2015, Richard Smith wrote: > On 10/23/2015 02:41 PM, Michael Richardson wrote: > Richard Smith wrote: > My test setup: >=20 > Laptop<--1000BaseT-->DUT<--1000baseT-->Server >=20 > So, given that the DUT is the only real constraint in the network, = what > do you expect to see from this setup? >=20 > Given that the probably DUT can't forward at Gb/s, and it certainly = can't > shape anything, it's gonna drop packets, and it's probably gonna drop = them in > Rx, having overrun the Rx-queue (so tail-drop). If there is too much = ram > (bufferbloated), then you'll see different results... >=20 > Setting ingress/egress to 10Mbit/s I expected to see the speed=20 > measurements bounce around those limits with the ping times staying in=20= > the low double digits of ms. What I saw however, was the data rates=20 > going well past 10Mbit limit and pings up to 2000 ms. >=20 > This is what I've seen in prior rrul testing using a the 50/10 cable=20= > link at our office and my 25(ish)/6 link at my apartment and a well=20 > connected server on the net. That however was using QoS and not SQM. >=20 > Its that a reasonable expectation? >=20 > -- Sent with K-@ Mail - the evolution of emailing. >=20 > Cerowrt-devel mailing list > Cerowrt-devel@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/cerowrt-devel >=20 >=20 > -- Sent with K-@ Mail - the evolution of emailing.