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Re: [RPRWG] Error in rate normalization?




Fredrick,

It is the effect of it not the unit of it.

Thanks.

Necdet

Fredrik Davik wrote:

> Necdet,
>
> The definition of localFairRate on page 207 states
>
> "..specified as the number of bytes that may be added per ageCoef
> agingIntervals."
>
> -Fredrik
>
> Necdet Uzun <nuzun@xxxxxxxxx> writes:
>
> > Fredrik,
> >
> > localFairRate is defined as number of bytes per agingInterval. AgeCoef is used to smooth it. It is not in the unit
> > of it.
> >
> > Thanks.
> >
> > Necdet
> >
> > Fredrik Davik wrote:
> >
> > > I am having troble interpreting the transformation of localFairRates
> > > to a rate that can be interpreted by other stations on the ringlet
> > > (normalized rate) and the way this is done in the draft
> > >
> > > Either I am having a bad day in office or else, something is wrong ;)
> > >
> > > Take a look below:
> > >
> > > localFairRate is specified in units of:
> > >
> > > 1.  localWeight * [bytes/(ageCoef * agingInterval)]
> > >
> > > 2.  normCoef = localWeight * rateCoef * ageCoef
> > >
> > > Where ageCoef and localWeight are per station/ringlet configured
> > > parameters and agingInterval is a global setting which depend on the
> > > link rate.
> > >
> > > The normalization process aims to distribute the rate information in a
> > > way that is not dependent on locally configured parameters, thus
> > > dividing 1.(localFairRate) above by 2. (normCoef) :
> > >
> > > We get :
> > >
> > > 3: ( localWeight * [bytes/(ageCoef * agingInterval)]) / (localWeight * rateCoef * ageCoef)
> > >
> > > 3. result when reorganized and simplified:
> > >    bytes / ( ageCoef * ageCoef * agingInterval * rateCoef)
> > >
> > > >From this I observe two things:
> > >
> > > a) The "normalized" value still contains the effect of the local
> > >    ageCoef parameter
> > >
> > > b) agingInterval is the same for all stations and could also be
> > >    removed from the expression by including it in normCoef:
> > >
> > > If normCoef is rewritten as:
> > >
> > > 4. normCoef = (localWeight * rateCoef)/ ( ageCoef * agingInterval)
> > >
> > > What we get when diving 1 by 4 is:
> > >
> > > 5. ( localWeight * [bytes/(ageCoef * agingInterval)]) / ((localWeight * rateCoef)/ ( ageCoef * agingInterval))
> > >
> > > 5. result when reorganized and simplified (this is the rate
> > >    distributed on the ring):
> > >
> > >   bytes/rateCoef
> > >
> > > When the normalized rate is received by another station, this is
> > > converted to a local rate by multiplying the normalized rate by
> > > normCoef (the modified one above) as before.
> > >
> > > Best Regards,
> > > Fredrik
> > > ---------------------------------------------
> > > Fredrik Davik
> > >                  Phone:       +47 67 82 83 88
> > >                  Mobil:       +47 45 24 91 88
> > >                  Fax:         +47 67 82 82 01
> > >                  Switchboard: +47 67 82 82 00
> > >
> > > mailto:bjornfd@xxxxxxxxx
> > >
> > > http://heim.ifi.uio.no/~bjornfd
> > > http://www.simula.no/people_one.php?people_id=22
> > >
> > > Simula Research Laboratory
> > > P.O.Box 134, Lysaker
> > > N-1325 Lysaker
> > > Norway
> >
> >
>
> --
> mvh
> Fredrik
> ---------------------------------------------
> Fredrik Davik
>                  Telefon:     +47 67 82 83 88
>                  Mobil:       +47 45 24 91 88
>                  Faks:        +47 67 82 82 01
>                  Sentralbord: +47 67 82 82 00
>
> mailto:bjornfd@xxxxxxxxx
>
> http://heim.ifi.uio.no/~bjornfd
> http://www.simula.no/people_one.php?people_id=22
>
> Simula Research Laboratory
> Postboks 134, Lysaker
> 1325 Lysaker