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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,
>> > ....
>> > 
>> 

cls09_fairness.pdf