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RE: Bug in cbq



Title: RE: Bug in cbq

I've seen similar behaviour.  My classes report around 1.5mbps when the specified rate is 1mbit.  Monitoring with snmp tools confirms that the rate is indeed more than specified.  Oddly, smaller rates, around 30kbit or so, seem to work properly.

> -----Original Message-----
> From: olshef@us.ibm.com [mailto:olshef@us.ibm.com]
> Sent: Tuesday, September 05, 2000 10:08 PM
> To: linux-diffserv@lrc.di.epfl.ch
> Subject: Bug in cbq
>
>
>
>
> Changing the bandwidth allocation for one class under cbq changes the
> allocation for other classes:
>
> Try this to set up two classes:
> ----------
> tc qdisc add dev eth0 root handle 1: cbq bandwidth 100Mbit
> avpkt 1000 mpu 64
> tc class add dev eth0 parent 1:0 classid :1 est 1sec 8sec cbq
> bandwidth 100Mbit rate 50Mbit weight 1 bounded isolated allot
> 1514 maxburst 10 avpkt
> 1000 split 1:0
> tc class add dev eth0 parent 1:0 classid :2 est 1sec 8sec cbq
> bandwidth 100Mbit rate 50Mbit weight 1 bounded isolated allot
> 1514 maxburst 10 avpkt
> 1000 split 1:0
>
>
> Then change the allocation for class 2:
> ---------------------------
> tc class change dev eth0 parent 1:0 classid :2 est 1sec 8sec
> cbq bandwidth 100Mbit rate 10Mbit weight 1 bounded isolated
> allot 1514 maxburst 10 avpkt
> 1000 split 1:0
>
> At full load, both classes report about 6.2Mbps, then after the change
> class 2 reports 1.3Mbps and class 1 reports 1.9Mbps....
>
>
> undo the change by:
> --------------
> tc class change dev eth0 parent 1:0 classid :2 est 1sec 8sec
> cbq bandwidth 100Mbit rate 40Mbit weight 1 bounded isolated
> allot 1514 maxburst 10 avpkt
> 1000 split 1:0
>
>
> And both classes are back up to 6.2Mbps.
>
> I'm trying to simply partition the outgoing bandwidth on my
> ethernet card -
> is there a better way to do this than using cbq?
>
>
> David P. Olshefski
> (914) 784-7639, Office H3-F32
> olshef@us.ibm.com
> IBM T.J. Watson Research
> 30 Saw Mill River Road
> Hawthorne, NY 10532
>
>