From: Chris Hugo (chrishugo@xxxxxxxxx)
Date: Wed Aug 28 2002 - 15:23:09 GMT-3
Hi Peng,
I derived my calculation for Be from the link you pointed out. This is a good l
ink. Like Colin, I too have been searching for some good links on this. Even a
lot of books are iffy on this particular subject.
chris hugo
Peng Zheng wrote: I totally got confused.
I think it's very clear under:
http://www.cisco.com/warp/public/125/traffic_shaping_6151.html
Is this link wrong?
--- Colin Barber wrote:
> Just when I thought I had FRTS sorted I have to
> re-think how BE is
> calculated :-(
>
> Why can't Cisco produce a document that defines
> things properly and has good
> explained example (and then remove all conflicting
> documents from the web
> site)? Too much to ask for?
>
> Colin
>
> -----Original Message-----
> From: Jim Brown [mailto:Jim.Brown@caselogic.com]
> Sent: 28 August 2002 17:11
> To: 'Volkov, Dmitry (Toronto - BCE)'; Jim Brown;
> 'Colin Barber'; 'Omer
> Ansari'
> Cc: 'ccielab@groupstudy.com'
> Subject: RE: I need FRTS help or review
>
>
> I think all you need to do is look at how many bit
> would be transmitted over
> time interval T over time interval TC. The software
> and hardware queues will
> buffer the packets until they can place them on the
> wire.
>
> This results in a maximum of 96Kbps during the first
> interval T.
>
> -----Original Message-----
> From: Volkov, Dmitry (Toronto - BCE)
> [mailto:dmitry_volkov@ca.ml.com]
> Sent: Wednesday, August 28, 2002 10:00 AM
> To: 'Jim Brown'; 'Colin Barber'; 'Omer Ansari'
> Cc: 'ccielab@groupstudy.com'
> Subject: RE: I need FRTS help or review
>
>
>
> Yes,
>
> But DEFINITION of Be inteprets it as BITS during
> FIRST Tc !!
> "The amount of excess data allowed to be sent during
> first Tc interval in
> bits once credit is built up."
>
> And we have to put in real config the actual number
> which corresponds to
> definition.
>
> You can not transmit so many bits during first Tc.
> If rate speed is much
> slower.
>
> Dmitry
>
> > -----Original Message-----
> > From: Jim Brown [mailto:Jim.Brown@caselogic.com]
> > Sent: Wednesday, August 28, 2002 11:35 AM
> > To: 'Colin Barber'; 'Omer Ansari';
> 'ccielab@groupstudy.com'
> > Subject: RE: I need FRTS help or review
> >
> >
> > You do not necessarily need 320Kps available
> during the first
> > interval. The
> > packets are software queued before they are placed
> onto the
> > TxRing. This is
> > the whole idea behind shaping.
> >
> > They are not placed on the wire at exactly the
> same speed
> > designated per TC
> > interval.
> >
> > List, if I'm way off base please correct me and
> help me see the light.
> >
> > -----Original Message-----
> > From: Colin Barber
> [mailto:Colin.Barber@telewest.co.uk]
> > Sent: Wednesday, August 28, 2002 9:09 AM
> > To: 'Omer Ansari'; 'ccielab@groupstudy.com'
> > Subject: RE: I need FRTS help or review
> >
> >
> > What's the access speed of the interface? If it's
> 96k then this is
> > incorrect. In the first time slot BC+BE=40000. For
> that
> > amount of data to be
> > transferred in the first timeslot the access speed
> will need to be
> > 40000*8=320kbps.
> >
> > Colin
> > -----Original Message-----
> > From: Omer Ansari [mailto:omer@ansari.com]
> > Sent: 28 August 2002 10:56
> > To: ccielab@groupstudy.com
> > Cc: steven.j.nelson@bt.com;
> Jim.Brown@caselogic.com;
> > kip.palmer@verizon.net
> > Subject: RE: I need FRTS help or review
> >
> >
> > Guys,
> >
> > so bottom line is Jim and Steve have correctly
> done this right?
> > It seems good to me, and I too want to stick this
> once and for all.
> >
> > omer
> >
> > On Mon, 26 Aug 2002 steven.j.nelson@bt.com wrote:
> >
> > > All
> > >
> > > Jim is correct in this one, his figures pan out
> as follows
> > >
> > > CIR 96000
> > > MINCIR 64000
> > > BE 32000
> > > BC 8000
> > > TC 0.125Ms
> > >
> > > So in 8 time slots (1 Second) he will transmit
> :-
> > >
> > > 0.125Ms 40000 (BC+BE)
> > > 0.125Ms 8000 (BC)
> > > 0.125Ms 8000 (BC)
> > > 0.125Ms 8000 (BC)
> > > 0.125Ms 8000 (BC)
> > > 0.125Ms 8000 (BC)
> > > 0.125Ms 8000 (BC)
> > > 0.125Ms 8000 (BC)
> > >
> > > Which is equivalent to 96K per second.
> > >
> > > And when no tokens are available then the MIN
> CIR will be
> > met by the 8000
> > BC
> > > * 8 = 64000
> > >
> > > Thanks to Jim for this one.
> > >
> > > Steve
> > >
> > >
> > > -----Original Message-----
> > > From: Jim Brown [mailto:Jim.Brown@caselogic.com]
> > > Sent: 26 August 2002 15:24
> > > To: 'kpalmer'
> > > Cc: 'ccielab@groupstudy.com'
> > > Subject: RE: I need FRTS help or review
> > >
> > >
> > > After your e-mails I rethought my stance on
> FRTS. I did a
> > little more
> > > research and I believe my original configuration
> at the
> > bottom of the post
> > > is the correct answer from a lab or testing
> context for a
> > 96Kbps port and
> > > 64Kbs contracted CIR.
> > >
> > > map-class frame-relay TestShape
> > > frame-relay cir 64000
> > > frame-relay be 32000
> > > frame-relay bc 8000
> > >
> > > I'm basing this on a single new piece of
> information I
> > turned-up. Check
> > the
> > > Networkers 2002 CCIE Power Session, in their
> FRTS example,
> > they configure
> > > the parameters exactly as I have described
> below.
> > >
> > > I still stand by my original assessment of
> Cisco's CIR set to the
> > providers
> > > CIR and Cisco's BE set to the difference between
> providers
> > CIR and port
> > > speed.
> > >
>
=== message truncated ===
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