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Re: CBQ vs. TBF



On Sun, 27 Feb 2000, Martin DEVERA wrote:

> >set up in most cases. Also, a few months ago, I tried to do exactly this,
> >and got funny rates with CBQ (off by a factor of 2-3, I think).
> 
> 
> yep, the same for me. Then I resolved that I set wrong bandwidth
> for top level link .. Now it works rather well ..
> Also can you please see my previous post (as I undestood, you
> are current maintainer) ?
> And one more question, why RTNETLINK is used for configuration
> instead of procfs ? Use of procfs could make configuration much
> easier (using subdirectories to express hierarchy). Are there any
> cons ?
> regards, martin

	With correct bandwidth, weight, rate, maxburst, avpkt etc
things seem to go correctly.  (maxburst out of sync with iface rate
and wrong avpkt screws the calculations)


	Another helpful item when doing small allocs (16Kbit -
256Kbit) on fast links (10 - 100 FD ethernet) is cranking the HZ value
from 100 on X86 to 1024.  IIRC the QOS stuff does its control every
HZ, by default, and every 10ms is not very often on a high rate
interface so small allocs tend to go over.  HZ=1024 is every ~ 1ms
(just under) instead of every 10ms.  I find this useful when I am
doing service based controls, ie having say 1:4 being a 512Kbit
class with different services going into 1:4 with a policed u32
filter.

Example

SMTP 256Kbit
Telnet 32Kbit
SNMP 16Kbit
FTP 64Kbit


	Allows be to cap service use when bandwidth gets tight, with
HZ=1024 the lower rate restrictions are +/- 5% instead of +/- 50%.
	
---
As folks might have suspected, not much survives except roaches, 
and they don't carry large enough packets fast enough...
        --About the Internet and nuclear war.