Re: FRTS and Be - first interval?

From: Andy (and123and@googlemail.com)
Date: Tue May 22 2007 - 11:43:46 ART


 Quote
> Why is Be 24000 and not 192000, if the definition of Be is "The number of
> non-committed bits the router is allowed to send above Bc during the *
first
*> interval Tc"
/Quote

The bit that confuses me, is that it says it sends during the first interval
Tc. This suggests (given default Tc)

Tc1 Tc2 Tc3 Tc4 Tc5 Tc6 Tc7 Tc8
(Bc + Be) (Bc) (Bc) (Bc) (Bc) (Bc) (Bc) (Bc)

Therefore I would config Be at 192000, so as to reach AR.
If we configure Be at 24000, and given that Be only sends during first Tc,
we are only getting Bc (192000) + Be for Tc1 (24000) which does not equal
Ar.

I understand the maths and how to acheive the figures, what I dont get is
why do we configure Be for each Tc "Tc1 - Tc8" when it says Be is only sent
during *first *Tc (Tc1).
-A

*************************************************************

On 22/05/07, Edison Ortiz <edisonmortiz@gmail.com> wrote:
>
> Quote
> > Why is Be 24000 and not 192000, if the definition of Be is "The number
> of
> > non-committed bits the router is allowed to send above Bc during the
> first
> > interval Tc"
> /Quote
>
> You have to use the same Tc value for the Be that was used for the Bc.
> As you stated originally, "use the default Tc value" which is 125ms.
>
> So they gave you the Access Rate, CIR and MinCIR.
>
> You take the CIR 192000 and multiply it for .125 which gives you the Bc
> (24000)
> You have another 192kbps for bursting (384000 - 192000) so you take that
> amount
> and do the same calculation (192000 * .125) to get the Be (24000)
>
>
>
>
> __
>
> Edison Ortiz
> (Routing & Switching, CCIE # 17943)
>
>
>
> ----- Original Message -----
> From: "Andy" <and123and@googlemail.com>
> To: "Group Study (E-mail)" <ccielab@groupstudy.com>
> Sent: Tuesday, May 22, 2007 5:42 AM
> Subject: FRTS and Be - first interval?
>
>
> > http://www.internetworkexpert.com/resources/01700368.htm
> > Slide 31 Example 2
> >
> > The example in above URL shows:
> > Router has AR of 384000
> > CIR of 192000
> > MinCIR 128000
> > Use default Tc and allow to burst up to AR.
> >
> > The configuration shows:
> > frame-relay CIR 192000
> > frame-relay bc 24000
> > frame-relay mincir 128000
> > frame-relay be 24000
> >
> > Why is Be 24000 and not 192000, if the definition of Be is "The number
> of
> > non-committed bits the router is allowed to send above Bc during the
> first
> > interval Tc"
> >
> > Confused :-/
> >
> > _______________________________________________________________________
> > Subscription information may be found at:
> > http://www.groupstudy.com/list/CCIELab.html



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