Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

RE: [RPRWG] Downstream shaper, major deficiencies



Title: RE: [RPRWG] Downstream shaper, major deficiencies

Dave,


Clarification on the latest pdf (re-attached):

page 212 line 12: "Resulting subclassA0 traffic load S251" should read "Resulting subclassA0 traffic load S61"
page 212 line 33: "...downstream S62 station..."           should read "...downstream S61 station..."

Lastly : S61 is a single transit buffer station?


Regards,

Harry


-----Original Message-----
From: David V James [mailto:dvj@xxxxxxxxxxxx]
Sent: Friday, June 20, 2003 7:34 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,
>> > ....
>> >
>>

 

cls09_fairness.pdf