LARTC - Oct 2000 - question about "rate"

Hi!

I am using DSL with 786Kbit downstream and 128Kbit upstream. When
someone fetches a file from my ftp server, my upstream is completely
blocked and download speeds from the internet of internal clients behind
the router slow down from ~90KB/s to 20-30KB/s. So I decided to limit
upstream bandwidth for access to the ftp-data port. Now I have two
questions:

1.) As you can see below, I allowed 56Kbit for ftp-data transfers. This
results in about 12KB/s. When I enter 64Kbit, full speed is consumed. Am
I doing something wrong here? I thought 96Kbit should result in 12K/s
and 128Kbit were full speed.

2.) How can I allow ftp-data transfers to get files at 128KBit speed,
when there is no other traffic on the line? I want to have ftp transfers
at a sufficient low priority, so that upstream and downstream from and
to internal hosts are not affected by my ftp-servers traffic.


This is the script I wrote:
--------------------------------------->
ALLOT="1492"
AVPKT="1000"
DEV="ppp0"
MAXBURST="20"
MAXRATE="128Kbit"
PERTURB="15"

tc qdisc del dev ${DEV} root handle 10:
tc qdisc add dev ${DEV} root handle 10: cbq bandwidth ${MAXRATE} avpkt
${AVPKT}

tc class add dev ${DEV} parent 10:0 classid 10:1 cbq bandwidth
${MAXRATE} \
        rate ${MAXRATE} allot ${ALLOT} prio 8 maxburst ${MAXBURST} avpkt
${AVPKT}

tc class add dev ${DEV} parent 10:1 classid 10:200 cbq bandwidth
${MAXRATE} \
        rate 56Kbit allot ${ALLOT} prio 5 maxburst ${MAXBURST} avpkt
${AVPKT} \
        bounded

tc qdisc add dev ${DEV} parent 10:200 sfq quantum ${ALLOT}b perturb
${PERTURB}

tc filter add dev ${DEV} parent 10:0 protocol ip prio 25 \
        u32 match ip sport 20 0xFFFF flowid 10:200
<---------------------------------------

Thanks in advance,
Andreas

Hello,
> 1.) As you can see below, I allowed 56Kbit for ftp-data transfers. This
> results in about 12KB/s. When I enter 64Kbit, full speed is consumed. Am
> I doing something wrong here? I thought 96Kbit should result in 12K/s
> and 128Kbit were full speed.
Hmm... same setup seems to work for me quite fine at 64Kbps, 65607 bits in
one second.
> 
> 2.) How can I allow ftp-data transfers to get files at 128KBit speed,
> when there is no other traffic on the line? I want to have ftp transfers
> at a sufficient low priority, so that upstream and downstream from and
> to internal hosts are not affected by my ftp-servers traffic.
Removing the "bounded" on your class 10:200 will allow the class to
borrow
bandwidth from other classes when they aren''t using it. This is
addressed
on the bandwidth limiting example, under "What to do with excess 
bandwidth".

By the way, how can I stop Netscape from opening a second port on the ftp
server instead of using port 20 for data transfer? Testing with ftp
downloads under netscape results un full bandwidth as this connection is
used for data instead of source port 20:
(output from netstat -na)
tcp       0      0 192.168.144.99:44212    192.168.144.99:1064 ESTABLISHED

Cheers,

Rodrigo Goya

On Fri, Oct 27, 2000 at 07:58:48PM +0200, Andreas Oberritter wrote:
> This is the script I wrote:
> --------------------------------------->
> ALLOT="1492"
> AVPKT="1000"
> DEV="ppp0"
> MAXBURST="20"
> MAXRATE="128Kbit"
> PERTURB="15"
> 
> tc qdisc del dev ${DEV} root handle 10:
> tc qdisc add dev ${DEV} root handle 10: cbq bandwidth ${MAXRATE} avpkt
> ${AVPKT
Can you specify the ''weight'' of your connection as well, one
tenth of
128kbit would seem in order. 

Regards,

bert hubert

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