Date: Thu, 21 Apr 2016 00:08:46 +0000 From: Rasool Al-Saadi <ralsaadi@swin.edu.au> To: Don Lewis <truckman@FreeBSD.org> Cc: "freebsd-ipfw@FreeBSD.org" <freebsd-ipfw@FreeBSD.org> Subject: RE: Dummynet AQM v0.1- CoDel and FQ-CoDel for FreeBSD's ipfw/dummynet Message-ID: <6545444AE21C2749939E637E56594CEA3C20C123@gsp-ex02.ds.swin.edu.au> In-Reply-To: <201604201711.u3KHBgnL077532@gw.catspoiler.org> References: <6545444AE21C2749939E637E56594CEA3C20AEFC@gsp-ex02.ds.swin.edu.au> <201604201711.u3KHBgnL077532@gw.catspoiler.org>
next in thread | previous in thread | raw e-mail | index | archive | help
> -----Original Message----- > From: Don Lewis [mailto:truckman@FreeBSD.org] > Sent: Thursday, 21 April 2016 3:12 AM > To: Rasool Al-Saadi <ralsaadi@swin.edu.au> > Cc: freebsd-ipfw@FreeBSD.org > Subject: Re: Dummynet AQM v0.1- CoDel and FQ-CoDel for FreeBSD's > ipfw/dummynet >=20 > On 20 Apr, Rasool Al-Saadi wrote: > > > > > >> -----Original Message----- > >> From: Don Lewis [mailto:truckman@FreeBSD.org] > >> Sent: Thursday, March 10, 2016 7:29 PM > >> To: Rasool Al-Saadi <ralsaadi@swin.edu.au> > >> Cc: aqm@ietf.org; freebsd-net@FreeBSD.org; freebsd- > ipfw@FreeBSD.org; > >> Grenville Armitage <garmitage@swin.edu.au> > >> Subject: Re: Dummynet AQM v0.1- CoDel and FQ-CoDel for FreeBSD's > >> ipfw/dummynet > >> > >> On 26 Feb, Rasool Al-Saadi wrote: > >> > Dear all, > >> > > >> > I would like to announce that we (myself and Grenville Armitage) > >> > released > >> Dummynet AQM v0.1, which is an independent implementation of CoDel > >> and FQ-CoDel for FreeBSD's ipfw/dummynet framework, based on the > IETF > >> CoDel [1] and FQ-CoDel [2] Internet-Drafts. > >> > We prepared patches for FreeBSD11-CURRENT-r295345 and FreeBSD > >> > 10.x- > >> RELEASE (10.0, 10.1, 10.2), and a technical report of our implementat= ion. > >> > > >> > Patches and documentation can be found in: > >> > http://caia.swin.edu.au/freebsd/aqm > >> > > >> > Technical report: > >> > http://caia.swin.edu.au/reports/160226A/CAIA-TR-160226A.pdf > >> > >> I've got some results with running this on my firewall in an attempt > >> to tame a severe bufferbloat problem on my ADSL connection to the > outside world. > >> > >> The raw speed numbers reported by my ADSL modem are 6016 Kb/s > >> downstream and 768 Kb/s upstream. I set my MTU to 1492 to avoid > >> fragmentation from PPPoE overhead. > >> > >> Using <http://www.dslreports.com/speedtest>; with things unthrottled, > >> I observe about 5050 Kb/s downstream and 648Kb/s upstream, with a > >> bufferbloat rating of F. > >> > >> I configured the system to use FQ-CoDel, with separate pipes for each > >> direction. Because of the slow upstream speed, I increased the > >> target value for the upstream direction to 25 ms since a maximum size > >> packet will require about 20 ms to send. I also set the > >> net.inet.tcp.experimental.initcwnd10 sysctl value to 0. The latter > >> seemed to help a lot. With this feature enabled, the initial packet > >> blast at the start of the upload caused a large initial latency > >> spike, and the initial transfer rate ended up being very slow and it > >> took a long time to ramp up to its maximum sustained value. > >> > >> My current dummynet pipe bandwidth settings are 4800 Kb/s > downstream > >> and > >> 615 Kb/s upstream. The speedtest results for these settings are > >> about 4600 Kb/s downstream and about 600 Kb/s upstream. I'm > somewhat > >> disappointed in the bandwith loss, but my bufferbloat rating has > >> improved to mostly A's with some B's. > >> > >> I do still see a large increase in latency at the start of transfers, > >> and then it oscillates for a while before settling down at a > >> reasonable value for the remainder of the transfer. I suspect this is= to be > expected. > >> > >> It would be nice if the implementation was able to account for the > >> PPPOE and ATM framing overhead like the Linux implementation does. I > >> think that would help performance when there is a mix of packet sizes. > > > > Dave T=E4ht suggests you to try a "quantum 300" for your 600kbit uplink= . >=20 > Actually I need to decrease the quantum from 1514 to 1506 in the other > direction as well. I decreased the MTU on this path to 1492 to compensat= e > for the PPPOE header that is added by my DSL router. The default 1500 by= te > MTU will result in fragmentation. If I don't change the quantum to match= , > then periodically two maximal size packets will be allowed from the same > flow. >=20 > > BTW, if you interested try our FQ-PIE implementation in Dummynet AQM > v0.2 in your configuration. >=20 > I'm planning on trying that when I have the time. I also want to test wi= th and > without ECN on the end station. If you went to test with ECN, please use Dummynet AQM v0.2 patch as v0.1 ha= s incorrect ECN implementation.=20 Regards, Rasool
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?6545444AE21C2749939E637E56594CEA3C20C123>