From: John Neiberger (neiby@xxxxxxxxxx)
Date: Wed Apr 03 2002 - 00:30:12 GMT-3
Okay, I just checked up on this because I obviously didn't have
a good handle on it. My last guess appears to be correct.
When configuring Be, the figure you use is per-interval
number. If you have 8 intervals of 125 ms and you want 64k
burst total, the Be value would be 8000.
However, the Be is *only* transmitted in the first interval
each second. It's not really divided up among the intervals,
even the the value is a per-interval amount. I was mistaken in
thinking that the Be value was the number of excess bits
transmitted per second.
Here's a great link that made it more clear to me:
http://www.cisco.com/warp/public/125/traffic_shaping_6151.html
HTH,
John
---- On Tue, 2 Apr 2002, John Neiberger (neiby@ureach.com)
wrote:
> I was under the impression that Be only related to excess
data
> in the first interval. So, if we wanted to burst up to 28000
> bps we'd want a Be of 28000, not 3500. If that's not the
case
> then I need to brush up on FRTS as well. :-) That's at
least
> the second thing today I've needed to check myself on.
>
> Then again, perhaps Be is specified as a per-interval number,
> yet the entire Be amount is only transmitted in the first
> interval? Hmm.... Off to CCO I go...
>
> John
>
>
>
> ---- On Tue, 2 Apr 2002, Bob Sinclair (bsin@erols.com) wrote:
>
> > Guy,
> >
> > My take on it is: (bc+be) X Tc = max rate
> >
> > Remember Be is bits per interval.
> >
> > So Be = (maxrate-cir)/ Tc
> >
> > Tc here is .125 seconds, 8 intervals per second
> >
> > Be= (128000 - 100000)/8 or 28000/8 = 3500
> >
> > To check: (12500 + 3500) X 8 = 16000 X 8 = 128000
> >
> > In English: Bc and Be are in Bits/interval. Max rate is
> (average
> > bits/interval plus excess bits/interval) per second. Here,
> the interval
> > is 1/8 second.
> >
> > -Bob
> >
> > ----- Original Message -----
> > From: "Lupi, Guy" <Guy.Lupi@eurekaggn.com>
> > To: <ccielab@groupstudy.com>
> > Sent: Tuesday, April 02, 2002 8:22 PM
> > Subject: FRTS
> >
> >
> > > If I want to send traffic at an average rate of 100K,
being
> able to
> > burst to
> > > 128K if credit is built up and dropping to a minimum of
56K
> during
> > > congestion, does this map class look correct? I am
trying
> to figure
> > out if
> > > I have this down or not, I am trying to follow the
> guidelines I found
> > on
> > > CCO. Thanks.
> > >
> > >
> > > map-class frame-relay tor1
> > > frame-relay cir 100000 (send
> traffic at an
> > average
> > > of 100000)
> > > frame-relay bc 12500 (cir/8)
> > > frame-relay be in 56000 (added
> automatically)
> > > frame-relay be out 28000 (burst in
> first
> > interval)
> > > frame-relay mincir 56000 (drop to a minimum of
> > > 56K)
> > > frame-relay adaptive-shaping becn
> > >
>
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