[LARTC] HTB steals bandwidth

[LARTC] HTB steals bandwidth

[Robert Brueckmann]

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.

Can someone explain to me why this happens? I think I didn't quite
understand HTB...

Thanks,
Robert


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Re: [LARTC] HTB steals bandwidth

[Stef Coene]

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??


Stef

-- 

stef.coene@docum.org
 "Using Linux as bandwidth manager"
     http://www.docum.org/
     #lartc @ irc.oftc.net

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Re: [LARTC] HTB steals bandwidth

[Robert Brueckmann]

> 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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Re: [LARTC] HTB steals bandwidth

[Stef Coene]

> 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.
16kbit is 2 kbyte and 1,3 is allmost 2kbyte.  So it seems to me that you are 
shaping what you want.  But what worried me was the fact that in you first 
post, the bandwidth dropped after 5 sec from 128kbit to 80kbit.    Do you 
still have the same problem with the lower rate/ceil?

> 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.
What's the load and memory usage on that box ?

Stef

-- 

stef.coene@docum.org
 "Using Linux as bandwidth manager"
     http://www.docum.org/
     #lartc @ irc.oftc.net

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Re: [LARTC] HTB steals bandwidth

[Mr. Adam ALLEN]

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On Thu, 2002-12-19 at 08:08, Robert Brueckmann wrote:
<SNIPPED>
> 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.
> 

I'm running HTB to split 512Kb DSL connection between two people, and it
seems to be working as expected... I can't remember any figures - but
never had reason for concern.

This is a P166 (no MMX), and 96Mb memory, and has NFS/HTTP/MYSQL
happening much of the time.


-- 
NAME    :	Adam Allen.
EMAIL   :	adam@dynamicinteraction.co.uk

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