From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stef Coene Date: Wed, 07 Aug 2002 19:09:34 +0000 Subject: Re: [LARTC] pb with ingress policy 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 Wednesday 07 August 2002 16:43, Thomas SPECK wrote: > Hi ! > > I have a single host which is connected via an 512kbit ADSL link to the > net. I quite often use some realaudio application that uses some bandwidth > and I want to avoid other traffic to scale that bandwidth down. So I used > some classes (with htb) on imq0 device and applied some filters and it > seems to work in most cases. However, there are some sites with which > download is interrupted if bandwidth is limited. I tried to trace it down > and did some simple test: > > modprobe imq numdevs=1 > tc qdisc add dev imq0 root handle 1: htb default 10 > tc class add dev imq0 parent 1: classid 1:10 htb rate 60kbit ceil 512kbit > burst 15k tc qdisc add dev imq0 parent 1:10 handle 10: sfq perturb 10 > iptables -t mangle -A PREROUTING -i ppp0 -j IMQ --todev 0 > ip li set imq0 up > > So now all traffic is limited to 60kbit. You limit all traffic to 512 kbit with the ceil parameter, not 60 kbit. The rate is used when you have 2 or more child classes with the same parent. > If I use some particular site for > downloading (with wget) I observe the following with tcpdump: At the > beginning there is a huge burst (wget indicating something like 45 kbps) > than speed decreases dramatically and achieves some equilibrium around > 60kbit. Then for some reason after about 15 seconds my host sends FIN to > the other site. Why ? ;-) Is that a problem with some queue being too full > after the burst at the beginning ? I tried to play with the burst option > and I also used the pmtu stuff (iptables -A FORWARD -p tcp --tcp-flags > SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu) without success. 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/