From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp121.iad3a.emailsrvr.com (smtp121.iad3a.emailsrvr.com [173.203.187.121]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by huchra.bufferbloat.net (Postfix) with ESMTPS id 1A16821F5D3 for ; Fri, 23 Oct 2015 15:53:45 -0700 (PDT) Received: from smtp24.relay.iad3a.emailsrvr.com (localhost.localdomain [127.0.0.1]) by smtp24.relay.iad3a.emailsrvr.com (SMTP Server) with ESMTP id 841CD1804E8; Fri, 23 Oct 2015 18:53:44 -0400 (EDT) Received: by smtp24.relay.iad3a.emailsrvr.com (Authenticated sender: dpreed-AT-reed.com) with ESMTPSA id 51AED1803D9; Fri, 23 Oct 2015 18:53:41 -0400 (EDT) X-Sender-Id: dpreed@reed.com Received: from [100.94.249.107] (2.sub-70-199-78.myvzw.com [70.199.78.2]) (using TLSv1.2 with cipher DHE-RSA-AES256-SHA) by 0.0.0.0:465 (trex/5.4.2); Fri, 23 Oct 2015 22:53:44 GMT User-Agent: K-@ Mail X-Priority: 3 In-Reply-To: <562A9611.4050403@gmail.com> References: <562A5BE5.6010101@gmail.com> <12883.1445625688@sandelman.ca> <562A9611.4050403@gmail.com> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----IR1IT649SSKFX4UY268G8ZL4WXBMV0" Content-Transfer-Encoding: 7bit From: "David P. Reed" Date: Fri, 23 Oct 2015 18:53:09 -0400 To: Richard Smith ,Michael Richardson Message-ID: 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: Fri, 23 Oct 2015 22:54:08 -0000 ------IR1IT649SSKFX4UY268G8ZL4WXBMV0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable In particular, the DUT should probably have no more than 2 packets of outb= ound queueing given the very small RTT=2E 2xRTT is the most buffering you w= ant in the loop=2E On Oct 23, 2015, Richard Smith = wrote: >On 10/23/2015 02:41 PM, Michael Richardson wrote: >> Richard Smith = wrote: >> > My test setup: >> >> > Laptop= <--1000BaseT-->DUT<--1000baseT-->Server >> >> So, given that the DUT is the= only real constraint in the network, >what >> do you expect to see from th= is setup? >> >> Given that the probably DUT can't forward at Gb/s, and it c= ertainly >can't >> shape anything, it's gonna drop packets, and it's probab= ly gonna drop >them in >> Rx, having overrun the Rx-queue (so tail-drop)=2E= If there is too much >ram >> (bufferbloated), then you'll see different r= esults=2E=2E=2E > >Setting ingress/egress to 10Mbit/s I expected to see the= speed >measurements bounce around those limits with the ping times stayin= g in >the low double digits of ms=2E What I saw however, was the data rat= es >going well past 10Mbit limit and pings up to 2000 ms=2E > >This is wha= t I've seen in prior rrul testing using a the 50/10 cable >link at our off= ice and my 25(ish)/6 link at my apartment and a well >connected server on = the net=2E That however was using QoS and not SQM=2E > >Its that a reasona= ble expectation? -- Sent with K-@ Mail - the evolution of emailing=2E ------IR1IT649SSKFX4UY268G8ZL4WXBMV0 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable In particular, the DUT should probably have = no more than 2 packets of outbound queueing given the very small RTT=2E 2xR= TT is the most buffering you want in the loop=2E

On Oct 23, 2015, Richard Smith <sm= ithbone@gmail=2Ecom> wrote:

On 10/23/2015 02:41 PM, Michael Rich=
ardson wrote:
Richard Smith <smithbone@gmail=2Ecom> wrote:
My test setup:

Laptop<--1000BaseT-->DUT<--1000bas= eT-->Server

So, given that the DUT is the= only real constraint in the network, what
do you expect = to see from this setup?

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 th= em in
Rx, having overrun the Rx-queue (so tail-drop)=2E = If there is too much ram
(bufferbloated), then you'll see= different results=2E=2E=2E

Setting ingress/= egress to 10Mbit/s I expected to see the speed
measureme= nts bounce around those limits with the ping times staying in
the low double digits of ms=2E What I saw however, was the data rate= s
going well past 10Mbit limit and pings up to 2000 ms= =2E

This is what I've seen in prior rr= ul testing using a the 50/10 cable
link at our office an= d my 25(ish)/6 link at my apartment and a well
connected= server on the net=2E That however was using QoS and not SQM=2E

Its that a reasonable expectation?

-- Sent with K-@ Mail - the evolution of emailing=2E<= /html> ------IR1IT649SSKFX4UY268G8ZL4WXBMV0--