Re: [Gen-art] Gen-art] Review: draft-ietf-pce-pcep-domain-sequence

[Dhruv Dhody <[e-mail]>]

Hi All, 

How is this - 

   IGP Area subobjects in the XRO are local to the current AS.  In case
   of multi-AS path computation to exclude an IGP area in a different
   AS, IGP Area subobject should be part of Explicit Exclusion Route
   Subobject (EXRS) in the IRO to specify the AS in which the IGP area
   is to be excluded.

I have attached the working copy diff for easy reference.  

Regards,
Dhruv

> -----Original Message-----
> From: Dhruv Dhody
> Sent: 02 November 2015 00:33
> To: 'Julien Meuric'; Joel Halpern Direct; Dhruv Dhody
> Cc: A. Jean Mahoney; General Area Review Team; draft-ietf-pce-pcep-
> [e-mail]
> Subject: RE: Gen-art] Review: draft-ietf-pce-pcep-domain-sequence
> 
> Hi All,
> 
> Sorry for delay in replying, let me try to send you proposed text
> tomorrow as per Julien's suggestion!
> 
> Regards,
> Dhruv
> 
> > -----Original Message-----
> > From: Julien Meuric [mailto:[e-mail]]
> > Sent: 31 October 2015 00:35
> > To: Joel Halpern Direct; Dhruv Dhody
> > Cc: A. Jean Mahoney; General Area Review Team; draft-ietf-pce-pcep-
> > [e-mail]; Dhruv Dhody
> > Subject: Re: Gen-art] Review: draft-ietf-pce-pcep-domain-sequence
> >
> > Hi Joel, hi Dhruv,
> >
> > Focusing on the Area ID issue, I'd support adding some text along
> with
> > Dhruv's proposal, but stricter (not just deferring to
> > "implementation's feeling"). I.e., Area IDs are AS-specific and
> > mustn't cross AS borders; AS-local Area IDs may be used inside an AS
> > (without restricting to the origin AS).
> >
> > See you in Yokohama,
> >
> > Julien
> >
> >
> > Oct. 30, 2015 - [e-mail]:
> > >>          Given that Exclude Route Objects are not interleaved with
> > >>     include Objects, is there a restriction that Area IDs may only
> > be
> > >>     excluded from paths within a single AS?
> > >>
> > >>
> > >> [Dhruv]: I guess this would depend on the PCE behavior during
> > >> inter-AS path computation i.e. PCEmay feel the area id subobjectis
> > >> irreleventand strips from the XRO before sending the request to
> > >> another PCE ​ or it might keep it intact.
> > >>
> > >>
> > >> This would be in s
> > >> ​pi​
> > >> ritof RFC 4874 where
> > >> ​-
> > >>
> > >>
> > >> 
> > >> The number of subobjects to be avoided, specified in the
> > >>     signaled XRO, may be constant throughout the whole path setup,
> > or the
> > >>     subobjects to be avoided may be removed from the XRO as they
> > become
> > >>     irrelevant in the subsequent hops of the path setup.
> > >>
> > >> We can always
> > >> ​use
> > >> EXRS in IRO specify the intentions much more clearly.
> > >>
> > >> If you agree, we can work on some text to add.
> > >
> > > I still can not see how the Excluded Route Object with an Area ID
> > will
> > > work.  How will a PCE which receives such a request know what AS it
> > > applies to?  It works fine if the whole path is within one AS.  But
> > if
> > > this is a multi-AS request, the AS elements, if present at all, are
> > in
> > > the IRO.
> > > The most obvious approach would be to declare that the PCE shall
> > > assume that all Area ID exclusions apply to the origin AS.