RE: [Pce] Last Call: <draft-ietf-pce-pcep-service-aware-12.txt> (Extensions to the Path Computation Element Communication Protocol (PCEP) to compute service aware Label Switched Path (LSP).) to Proposed Standard

[Dhruv Dhody <[e-mail]>]

Hi Adrian, 

Ack.
Updated in working copy. 

Regards,
Dhruv

> -----Original Message-----
> From: Adrian Farrel [mailto:[e-mail]]
> Sent: 31 August 2016 18:48
> To: Dhruv Dhody <[e-mail]>; [e-mail]
> Cc: [e-mail]; [e-mail];
> [e-mail]; 'Dhruv Dhody' <[e-mail]>
> Subject: RE: [Pce] Last Call: <draft-ietf-pce-pcep-service-aware-12.txt>
> (Extensions to the Path Computation Element Communication Protocol (PCEP)
> to compute service aware Label Switched Path (LSP).) to Proposed Standard
> 
> Nice job and very fast!
> 
> I am happy with all the changes, but one caution...
> 
> > > 4.2.3.1 should not define legacy behavior. A legacy node will not
> > > see this spec and cannot be influenced by what you write. So...
> > >
> > > OLD
> > >    If a PCE receives a PCReq message containing a BU object, and the
> PCE
> > >    does not understand or support the BU object, and the P bit is clear
> > >    in the BU object header then the PCE SHOULD simply ignore the BU
> > >    object.
> > >
> > >    If the PCE does not understand the BU object, and the P bit is set
> in
> > >    the BU object header, then the PCE MUST send a PCErr message
> > >    containing a PCEP-ERROR Object with Error-Type = 3 (Unknown object)
> > >    and Error-value = 1 (Unrecognized object class) as per [RFC5440].
> > > NEW
> > >    The behavior of a PCE that does not understand an object that it
> > >    receives on PCReq message is defined in [RFC5440] and depends on the
> > >    setting of the P bit in the object header (P bit clear means ignore
> > >    the object, P but set means return an "Unknown object" error).
> > > END
> > >
> > [Dhruv] I have updated it as -
> >      If the BU object is unknown/unsupported, the PCE MUST follow
> >      procedures defined in [RFC5440]. That is, if the P bit is set, the
> >      PCE sends a PCErr message with error type 3 or 4 (Unknown / Not
> >      supported object) and error value 1 or 2 (unknown / unsupported
> >      object class / object type), and the related path computation
> >      request MUST be discarded.  If the P bit is cleared, the PCE is
> >      free to ignore the object.
> 
> You still have normative language in this document to describe how an
> implementation that has not read this document is required to behave.  I
> don't think that can work.
> 
> I suggest s/MUST/will/.
> 
> Cheers,
> Adrian