From: David Timmons (masterdt@yahoo.com)
Date: Mon Jul 03 2006 - 14:32:24 ART
Thanks,
I think RFC's have helped. I will think about what I
have read for a while.
dt
--- Elias Chari <elias.chari@gmail.com> wrote:
> Here is the RFCs guys, on which class based policing
> is based on
>
> http://www.ietf.org/rfc/rfc2698.txt
>
> http://www.ietf.org/rfc/rfc2697.txt
>
>
http://www.cisco.com/en/US/tech/tk543/tk545/technologies_tech_note09186a00800d7276.shtml#topic5
>
>
> On 7/3/06, David Timmons <masterdt@yahoo.com> wrote:
> >
> > Hi,
> >
> > I don't think you compute a Tc for policing. I
> have
> > not found a link that even talks about the use of
> Tc
> > with policing. I'll try to find a link that talks
> > about the time interval. I do agree that this is
> the
> > formula for computing the Tc for shaping.
> >
> >
> > I wonder if the rate command is from the Car days.
> > Maybe it has to be in 8k increments? I did see
> where
> > it is used for traffic that is sent to the control
> > plan.
> >
> > Here is an example. we are told to limit a
> particular
> > flow to 8,000 bits/s. We are also told that the we
> the
> > flow we are watching is 1024 bytes; however, we
> would
> > like to allow for any size packet with a minimum
> burst
> > size. What do you think you would list as your
> > policing statement?
> >
> > --- Paul Dardinski <pauld@marshallcomm.com> wrote:
> >
> > > Dave,
> > >
> > > From below, tc would be cir=bc/tc, so
> 8000=12000/tc
> > > or tc=12000/8000=1.5
> > > seconds.
> > >
> > > Be is totally separate from the equation. The
> below
> > > statement would
> > > allow an excess burst of 16000bps over the same
> 1.5
> > > second tc span.
> > >
> > > I never received any real answer as to the
> > > difference of police cir vs
> > > just police, so I'm assuming they are the
> > > same.........
> > >
> > > -----Original Message-----
> > > From: David Timmons [mailto:masterdt@yahoo.com]
> > > Sent: Monday, July 03, 2006 10:58 AM
> > > To: Paul Dardinski; Cisco certification
> > > Subject: Re: Police "cir" vs police
> > >
> > >
> > > HI,
> > >
> > > I have had the same questions. I am also having
> > > problems understanding how the Bc is actually
> > > interpreted. For example, what does this really
> > > mean?
> > >
> > > police cir 8000 bc 1500 be 2000
> > >
> > > Do we use the CIR to compute a time interval? Is
> it
> > > just 1500 per second? Do we have a way to
> compute a
> > > time interval? I have only found a recommended
> value
> > > for Bc and Be from Cisco:
> > > normal burst = configured rate * (1 byte)/(8
> bits)
> > > *
> > > 1.5 seconds
> > > extended burst = 2 * normal burst
> > >
> > > Many QOS books say that policing does not really
> use
> > > Tc the same as in shaping. I just don't
> understand
> > > how
> > > we evaluate the time period for the Bc and Be.
> > >
> > >
> > >
> > >
> > > --- Paul Dardinski <pauld@marshallcomm.com>
> wrote:
> > >
> > > > I see the "police cir" command in the cco only
> > > > occasionally. I can't
> > > > seem to locate difference between using just
> > > police
> > > > command vs police
> > > > cir (mqc).
> > > >
> > > >
> > > >
> > > > Any help?
> > > >
> > > >
> > > >
> > > > PD
> > > >
> > > >
> > >
> >
>
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