From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stef Coene Date: Fri, 07 Nov 2003 18:05:28 +0000 Subject: Re: [LARTC] TBF tunning Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lartc@vger.kernel.org On Friday 07 November 2003 18:34, Maria Joana Urbano wrote: > Hi all, > > I am trying to tune tbf qdisc. My upstream configuration is as follows: > > tc qdisc add dev $DEV root handle 1: cbq avpkt 1000 bandwidth 100mbit > tc class add dev $DEV parent 1:0 classid 1:1 cbq rate ${UP_RATE}kbit \ > allot 1500 prio 5 bounded > tc qdisc add dev $DEV parent 1:1 handle 10: tbf rate ${UP_RATE}kbit \ > burst $BURST limit $LIMIT mtu $MTU > tc filter add dev $DEV parent 1:0 protocol ip prio 18 u323 match ip \ > dst 0.0.0.0/0 flowid 1:1 > > I tried several combinations of BURST (from 10KB until there is no pkt > drops at tbf) and LIMIT values (corresponding to latencies of 40ms, 70ms > and 140ms). MTU is set to 1500, the MTU of the link. I tested this > configuration with several combinations of TCP flows and UDP flows > (seperately). However, the best value I got for throughput was about 90% > of UP_RATE. > > My question is: is it possible to get better results with tbf, with > throughput values closer to UP_RATE? And what should be changed in the > script above to get it better? You don't need a tbf qdisc if you have a bounded class. The traffic is already bounded by the cbq class. Stef -- stef.coene@docum.org "Using Linux as bandwidth manager" http://www.docum.org/ #lartc @ irc.openprojects.net _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/