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RE: [RPRWG] Downstream shaper, major deficiencies




Much better - thanks,
Sam

> -----Original Message-----
> From: David V James [mailto:dvj@xxxxxxxxxxxx] 
> Sent: Friday, June 20, 2003 4:34 PM
> To: Blakey, Sam
> Cc: Rpr GroupOf Ieee
> Subject: RE: [RPRWG] Downstream shaper, major deficiencies
> 
> 
> Sam,
> 
> The previous pdf was generated from a large pdf file
> by deleting irrelevant pages from within acrobat.
> 
> I generated a new version by printing only the relevant
> pages to a postscript printer, then distilling the
> output. This has never failed to be portable in the
> past, although a first surprize can always happen.
> 
> So, please try this attachment. For convenience,
> I have forwarded this to others that may have had
> problems.
> 
> DVJ
> 
> 
> David V. James
> 3180 South Ct
> Palo Alto, CA 94306
> Home: +1.650.494.0926
>       +1.650.856.9801
> Cell: +1.650.954.6906
> Fax:  +1.360.242.5508
> Base: dvj@xxxxxxxxxxxx  
> 
> >> -----Original Message-----
> >> From: Blakey, Sam [mailto:Sam.Blakey@xxxxxxx]
> >> Sent: Friday, June 20, 2003 2:43 PM
> >> To: 'David V James'
> >> Subject: RE: [RPRWG] Downstream shaper, major deficiencies
> >> 
> >> 
> >> Hi David,
> >> I'm having trouble with the pdf - only the first page is 
> readable - 
> >> scrolling down causes error. Thanks,
> >> Sam
> >> 
> >> 
> >> > -----Original Message-----
> >> > From: David V James [mailto:dvj@xxxxxxxxxxxx]
> >> > Sent: Friday, June 20, 2003 1:07 PM
> >> > To: Dongmei Wang; stds-802-17@xxxxxxxx
> >> > Cc: David V. James; John Lemon; Jon Schuringa; K. K. 
> >> > Ramakrishnan; Khaled Amer; Kshitij Kumar; Leon Bruckman; 
> >> > Necdet Uzun; Robert D Love; Stein Gjessing; Yan Robichaud
> >> > Subject: [RPRWG] Downstream shaper, major deficiencies
> >> > 
> >> > 
> >> > Dongmei,
> >> > 
> >> > I'll try to read your concers with the downstream shaper
> >> > credits in more detail, but it sounds like this relatively 
> >> > easily managed by a change in limits or resets when nothing 
> >> > is ready to be sent.
> >> > 
> >> > However, I believe there is a far more major problem with the
> >> > downstream shaper: it excludes STQ and add of classB. This 
> >> > can cause violation of classA0 guarantees, due to the 
> >> > cumulative effect of partially filled upstream STQs after 
> >> > transient loading conditions.
> >> > 
> >> > I have summarized this concern in the attached pdf writeup.
> >> > Also listed are other problems related to the coupling of 
> >> > fairness-eligible and upper-class traffic. I have not yet had 
> >> > the time to write them in the same level of detail.
> >> > 
> >> > I believe the basic premise of our fairness protocols is not
> >> > bad, but there are significant remaining problems to be 
> >> > solved. Unfortunately, its hard to see these through the 
> >> > implementation details of Clause 9. I hope my writeups will help.
> >> > 
> >> > For members of the FAH, this fulfills one of my action items:
> >> > >> On the topic of subclassA0.
> >> > >> Action items:
> >> > >>   DVJ,Stein,Jon to coolaborate on scenario
> >> > >>   Stein&Jon to coolaborate on simulation
> >> > I hereby hand off this scenario for Stein&Jon review...
> >> > 
> >> > DVJ
> >> > 
> >> > David V. James
> >> > 3180 South Ct
> >> > Palo Alto, CA 94306
> >> > Home: +1.650.494.0926
> >> >       +1.650.856.9801
> >> > Cell: +1.650.954.6906
> >> > Fax:  +1.360.242.5508
> >> > Base: dvj@xxxxxxxxxxxx
> >> > 
> >> > >> -----Original Message-----
> >> > >> From: owner-stds-802-17@xxxxxxxxxxxxxxxxxx
> >> > >> [mailto:owner-stds-802-17@xxxxxxxxxxxxxxxxxx]On Behalf Of 
> >> > >> Dongmei
> >> > >> Wang
> >> > >> Sent: Friday, June 20, 2003 6:41 AM
> >> > >> To: Jon Schuringa
> >> > >> Cc: chwang; stds-802-17@xxxxxxxx
> >> > >> Subject: Re: [RPRWG] A problem about shperD in Draft 2.2
> >> > >> 
> >> > >> 
> >> > >> 
> >> > >> Jon/Chao:
> >> > >> I just noticed this discussion. I have implemented 
> the shaperD 
> >> > >> in my simulator,
> >> > ....
> >> > 
> >> 
>