Dropping the Local Overbooking Multiplier (LOM) method from DS-TE specs?

["Francois Le Faucheur (flefauch)" <flefauch@cisco.com>]

Kireeti,

Once upon a time, we merged 3 technical proposals for DS-TE (one of
which was yours) into a common one. One of the capabilities that was
unique to your proposal was the ability to support overbooking ratios
which are different on a per CT AND per link basis (while the other
methods supported different ratios on different links and different
ratios on a per CT basis, not not on a per CT and per-link basis). Back
then you made a argument that there was some value in allowing this.
This resulted in the addition of the optional Local Overbooking
Multiplier (LOM) method in the DS-TE specs.

A number of people commented that considering the ratio of complexity vs
functionality for this particular capability, we may be better off
issueing the base DS-TE specs without this for now and then add this
capability later or in a separate document. I personnally also favors
such an approach.

What is your take on this?

Cheers

Francois

>> -----Original Message-----
>> From: Jim Boyle [mailto:jboyle@pdnets.com] 
>> Sent: 24 May 2003 02:31
>> To: Francois Le Faucheur (flefauch)
>> Cc: te-wg@ops.ietf.org; Lai, Wai S , ALABS
>> Subject: RE: Reflecting new-MAM/SAM definition in diff-te drafts 
>> 
>> 
<clip>
>> 
>> btw... I also think LOMs are lots of complexity for little gain :)
>> 
>> 
>> 
>> On Tue, 20 May 2003, Francois Le Faucheur (flefauch) wrote:
>> 
>> > Jerry,
>> > 
>> > >> -----Original Message-----
>> > >> From: Ash, Gerald R (Jerry), ALABS [mailto:gash@att.com] 
>> > >> Sent: 20 May 2003 17:35
>> > >> To: Dimitry Haskin; Francois Le Faucheur (flefauch)
>> > >> Cc: Ash, Gerald R (Jerry), ALABS; te-wg@ops.ietf.org; Lai, 
>> > >> Wai S (Waisum), ALABS
>> > >> Subject: RE: Reflecting new-MAM/SAM definition in diff-te drafts
>> > >> 
>> > >> 
>> > >> Dimitry, Francois,
>> > >> 
>> > >> > >     o SUM (Reserved (CTc)) <= Max Reservable Bandwidth, 
>> > >> > >         for all "c" in the range 0 <= c <= (MaxCT-1)
>> > >> > > 
>> > >> > > However, this formula is incorrect for DS-TE when per-CT 
>> > >> > > LOM's are used, since the above formula only 
>> reflects the Max 
>> > >> > > Reservable Bandwidth for the entire link, and does not 
>> > >> > > reflect the per-CT local overbooking factors.  So what 
>> > >> > > formula do you suggest when per-CT LOM's are used?
>> > >> 
>> > >> > Wouldn't 'Reserved (CTc)' it the above formula already 
>> > >> accounts for the
>> > >> > overbooking multiplier at CTc?  I don't see how this 
>> > >> formula precludes
>> > >> > per-CT LOM's to be used. Please explain.
>> > >> 
>> > >> Are you then proposing these formulas:
>> > >> 
>> > >> 1. When per-CT LOMs are not used:
>> > >> 
>> > >>      o SUM (Reserved(CTc)) <= Max Reservable Bandwidth, 
>> > >>          for all "c" in the range 0 <= c <= (MaxCT-1)
>> > >> 
>> > >> 2. When per-CT LOMs are used:
>> > >> 
>> > >>      o SUM (Normalized(CTc)) <= Max Reservable Bandwidth, 
>> > >>          for all "c" in the range 0 <= c <= (MaxCT-1)
>> > >> 
>> > >> Is that correct?  Please confirm, and/or give the formulas 
>> > >> you propose.
>> > 
>> > Yes, this is exactly what I propose.
>> > I think this is similar to what you were proposing, only 
>> using "Max Res
>> > Bw" instead of "Max Link Bw". 
>> > 
>> > Sorry I didn't make that very clear before.
>> > 
>> > Cheers
>> > 
>> > FRancois
>> > 
>> > >> 
>> > >> Thanks,
>> > >> Jerry
>> > >> 
>> > 
>> > 
>> > 
>> > 
>> 
>>