Re: [LARTC] HTB steals bandwidth

["Robert Brueckmann" <killerbob@musicalica.de>]

> On Monday 16 December 2002 18:02, Robert Brueckmann wrote:
> > Hi!
> >
> > I just tested my HTB setup. But I have a problem. Let's assume I run the
> > following script (even if it might do nothing useful, just for
> > demonstrating my problem):
> >
> > #!/bin/bash
> > /usr/sbin/tc qdisc add dev ppp0 root handle 1: htb default 12
> > /usr/sbin/tc class add dev ppp0 parent 1: classid 1:1 htb rate 125kbit
ceil
> > 125kbit
> > /usr/sbin/tc class add dev ppp0 parent 1:1 classid 1:14 htb rate 125kbit
> > ceil 125kbit prio 0
> > iptables -A POSTROUTING -t mangle -o ppp0 -p tcp --dport ftp-data -j
> > MARK --set-mark 14
> > tc filter add dev ppp0 parent 1:0 prio 0 protocol ip handle 14 fw flowid
> > 1:14
> >
> > I have an adsl-connection (768kbit down/128kbit up), Linux kernel
2.4.20.
> > The script should do nothing to an outgoing ftp-upload, since I grant
all
> > the available bandwith to it. No other traffic is happending during all
> > that, only one ftp-upload from a computer inside the LAN. I start the
> > upload without the rules above, and the upload is at a constant maximum
of
> > 128kbit/sec. After running the script above and waiting for say 5
seconds,
> > the upload speed drops down to app. 80 kbit/s! After removing the rules
> > above, the speed climbs up again to top speed.
> Have you tried with other rates and ceil values?
> And you defined a default class 12, but there is no such class.
> Ftp-data can use dynamic ports.  So can you check that the iptables line
with
> "--dport ftp-data"  is really catching the ftp packets??
>

If I reduce rate and ceil, it doesn't work properly either. I tried setting
the rate to 8kbit and the ceil to 16kbit and the upload did get less than
2kbyte/s, it was app. 1,3kbyte/s.

I modified the script to satisfy the need for the default class 12:

#!/bin/bash
/usr/sbin/tc qdisc add dev ppp0 root handle 1:0 htb default 12
/usr/sbin/tc class add dev ppp0 parent 1:0 classid 1:1 htb rate 125kbit ceil
125kbit
/usr/sbin/tc class add dev ppp0 parent 1:1 classid 1:12 htb rate 25kbit ceil
125kbit prio 1
/usr/sbin/tc class add dev ppp0 parent 1:1 classid 1:14 htb rate 100kbit
ceil 125kbit prio 0
iptables -A POSTROUTING -t mangle -o ppp0 -p tcp --dport ftp-data -j
MARK --set-mark 14
tc filter add dev ppp0 parent 1:0 prio 0 protocol ip handle 14 fw flowid
1:14

The ftp-data-port rule works for all active ftp-connections, and the packet
dounter of the rule increases just as I expected.

Any ideas, why the rate crashes down with these rules? May the
processor-power be the problem? The router is a Pentium-200, 64mb ram.

Thanks,
Robert


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