RE: [Pce] draft-leroux-pce-of-00.txt

Hi JL, 

> -----Original Message-----
> From: LE ROUX Jean-Louis RD-CORE-LAN 
> [mailto:jeanlouis.leroux@orange-ftgroup.com] 
> Sent: Wednesday, March 14, 2007 1:52 PM
> To: ASH, GERALD R, ATTLABS; pce@ietf.org
> Subject: RE: [Pce] draft-leroux-pce-of-00.txt 
> 
> Hi Jerry, 
> 
> > -----Message d'origine-----
> > De : ASH, GERALD R, ATTLABS [mailto:gash@att.com] 
> > Envoyé : vendredi 9 mars 2007 05:28
> > À : LE ROUX Jean-Louis RD-CORE-LAN; pce@ietf.org
> > Objet : RE: [Pce] draft-leroux-pce-of-00.txt 
> > 
> > Hi JL,
> > 
> > > -----Original Message-----
> > > From: LE ROUX Jean-Louis RD-CORE-LAN
> > > [mailto:jeanlouis.leroux@orange-ftgroup.com]
> > > Sent: Tuesday, March 06, 2007 6:50 PM
> > > To: ASH, GERALD R, ATTLABS; pce@ietf.org
> > > Subject: RE: [Pce] draft-leroux-pce-of-00.txt
> > > 
> > > Hi Jerry,
> > > 
> > > Thanks for the feedback and comments.
> > > 
> > > Please see inline,
> > > 
> > > > -----Message d'origine-----
> > > > De : ASH, GERALD R, ATTLABS [mailto:gash@att.com] Envoyé 
> > : > samedi 3 
> > > > mars 2007 01:54 À : LE ROUX Jean-Louis RD-CORE-LAN; 
> > > > pce@ietf.org Cc 
> > > > : ASH, GERALD R, ATTLABS Objet : RE: [Pce] 
> > > > draft-leroux-pce-of-00.txt
> > > > 
> > > > Hi JL,
> > > > 
> > > > Looks like a good start.  
> > > > 
> > > > Looking through the IANA section, I don't see 
> registration of the 
> > > > objective functions (OFs) required in Section 5.1.17 of
> > > > http://www.rfc-editor.org/rfc/rfc4657.txt:
> > > > 
> > > > "  The PCECP MUST support at least the following 
> > > > "unsynchronized"
> > > >    functions:
> > > > 
> > > >    - Minimum cost path with respect to a specified metric
> > > >      (shortest path)
> > > >    - Least loaded path
> > > >    - Maximum available bandwidth path
> > > > 
> > > >    Also, the PCECP MUST support at least the following 
> > > >    "synchronized" objective functions:
> > > > 
> > > >    - Minimize aggregate bandwidth consumption on all links
> > > >    - Maximize the residual bandwidth on the most loaded link
> > > >    - Minimize the cumulative cost of a set of diverse paths"
> > > > 
> > > > Shouldn't these standard OFs and their parameters be 
> > > > registered from 
> > > > the start?
> > > 
> > > Actually we prefer to keep this draft generic, and define 
> > > specific 
> > > objective functions in other documents. For instance 
> > > draft-lee-pce-global-concurrent-optimization-02.txt 
> > > requests for three 
> > > code points within the OF registry.
> > 
> > I guess I have the same question.  Which PCEP document(s) 
> > will specify the missing 6 objective functions, listed above, 
> > as required in Section 5.1.17 of the PCECP Generic 
> > Requirements (RFC 4657)?
> 
> Two objective functions listed in 5.1.17 are specified in 
> section 5.1 of
> draft-lee-pce-global-concurrent-optimization-02.txt.
> We can add other synchronized objective functions in the next 
> revision of the gco draft.
> 
> > I don't think these should be 
> > specified in 'other' (unnamed) documents, they should appear 
> > in the main PCEP specification document 
> > http://www.ietf.org/internet-drafts/draft-ietf-pce-pcep-07.txt
> 
> Hum, this would create dependency between the PCEP spec which 
> is stable and this new OF draft.
> 
> > , or perhaps in draft-leroux-pce-of-00.txt.
> 
> We don't really like this option as we want to keep the OF 
> draft generic.
> 
> One could write a short draft that would define a set of 
> straightforward unsynchronized objective functions including 
> those we listed in 4657.

IMO an important missing PCECP requirement is identified in http://www.ietf.org/internet-drafts/draft-ietf-pce-pcep-07.txt Appendix A (Compliance with the PCECP Requirement Document):

"   Here is the list of currently unsatisfied requirements:

   o  Allow to select/prefer from advertised list of standard objective
      functions/options

   o  Allow to customize objective function/options

   o  Support "unsynchronized" & "synchronized" objective functions"

They all deal with the missing 6 objective functions required in RFC 4657, and are an important omission in PCEP, so far.

You say that PCEP is 'stable' so you don't want to add them there?  Does that mean no further changes to PCEP before WGLC?  If so, the omission would be brought up during WGLC as an important gap in PCEP.

You don't want them in the OF draft, OK, your call.

Finally, once again, I don't think other new drafts (e.g., draft-lee-pce-global-concurrent-optimization-02.txt) that specify perhaps *new* PCEP requirements, should be satisfying the original RFC 4657 PCECP requirements on PCEP.  You also say 'We can add other synchronized objective functions in the next revision of the gco draft.'  I don't think that's the right place to satisfy the PCECP requirements.  And furthermore you say that yet another draft 'would define a set of straightforward unsynchronized objective functions including those we listed in 4657.'  It doesn't make sense IMO, rather, all 6 of these objective functions should be specified in the PCEP document.

It would be good to have other opinions on this.

Thanks,
Regards,
Jerry

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