From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stef Coene Date: Sun, 22 Dec 2002 11:09:12 +0000 Subject: Re: [LARTC] HTB quantum for small rates 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 Sunday 22 December 2002 03:37, Hannes Ebner wrote: > hi devik, > > i have found the following you have written some time ago: > > It is important to know that for precise operation quantums need to > > be as small as possible and larger than MTU. Normaly you don't need > > to specify quantums manualy as HTB chooses precomputed values. It > > computes classe's quantum (when you add or change it) as its rate > > divided by r2q global parameter. Its default value is 10 and because > > typical MTU is 1500 the default is good for rates from 15 kBps (120 > > kbit). For smaller minimal rates specify r2q 1 when creating qdisc - > > it is good from 12 kbit which should be enough. If you will need you > > can specify quantum manualy when adding or changing the class. > > what would be the best solution for rates smaller than 120kbit? i don't > know how the higher rates are affected by scaling r2q down to 1, but > would this be a solution for rates from 12kbit? > > would it be better to calculate the quantum for each rate or to set a > small quantum for all rates? The best you can do is following this rules and choose a good r2q : - 1500 < rate_small / r2q - rate_bigg / r2q < 60.000 with - rate_small = smallest rate - rate_bigg = biggest rate Quantum is only used if you have 2 or more class fighting for remaining bandwidth from the same parent. And with remaining, I mean that each class already received it's rate and that the parent has some bandwidth left. Stef -- stef.coene@docum.org "Using Linux as bandwidth manager" http://www.docum.org/ #lartc @ irc.oftc.net _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/