RE: calculating burst size for "mls qos aggregate-policer" on

Persio,
Sorry I'm in a class right now but in cases like this my recommendation would
be that you open a case with Cisco TAC and get them to do the job. Even if you
find the best certification-based answer here, it's not necessarily the same
thing as TAC best practices.

--------------------------
Kambiz Agahian
CCIE (R&S)
CCSI, WAASSE, RSSSE
Technical Instructor
CCBOOTCAMP - Cisco Learning Solutions Partner (CLSP)
Email: kagahian_at_ccbootcamp.com
Toll Free: 877-654-2243
International: +1-702-968-5100
Skype: skype:ccbootcamp?call
FAX: +1-702-446-8012
YES! We take Cisco Learning Credits!
Training And Remote Racks: http://www.ccbootcamp.com
OEQ Voice Waiver: http://www.ccbootcamp.com/noeqvoice.html
OEQ R&S Waiver: http://www.ccbootcamp.com/noeqrs.html
OEQ Commercial: http://www.ccbootcamp.com/noeq.mpg

-----Original Message-----
From: nobody_at_groupstudy.com on behalf of Persio Pucci
Sent: Mon 4/19/2010 11:19 AM
To: ccielab_at_groupstudy.com
Subject: Re: calculating burst size for "mls qos aggregate-policer" on
Cat6500

anybody?

On Thu, Apr 15, 2010 at 4:00 PM, Persio Pucci <persio_at_gmail.com> wrote:

> hi folks,
>
> I am trying to determine burst sizes for policies to be used on a Cat6500
> using mls qos aggregate-policer, but I am not confident on the numbers I am
> getting.
>
> For instance, for a 1mbps (1024000bps) policy, I would use a CIR of 1024000
> bps. The Cat6500 literature (
>
http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2SXF/native/
configuration/guide/qos.html#wp1726251) says
> that the Tc is 1/4000sec (0.25ms). For that Tc, I would have to use:
>
> CIR=Bc/Tc
>
> 1024000=Bc/(1/4000)
>
> Bc=1024000*(1/4000)
>
> Bc=256
>
>
> That being 256 bits. Considering the normal burst size field asks for a
> value in bytes, that makes 256/8=32 bytes, making my config line:
>
> mls qos aggregate-policer 1mbps 1024000 32 32 conform-action transmit
>> exceed-action drop violate-action drop
>
>
> The burst value does not sound reasonable for me. Wanted to check with you
> guys if I am missing something here.
>
> Persio

Blogs and organic groups at http://www.ccie.net
Received on Mon Apr 19 2010 - 11:27:32 ART