Re: terminology wa Re: XML basics Re: LC model draft draft-ietf-forces-model-07.txt

----- Original Message -----
From: "Joel M. Halpern" <[email protected]>
To: <[email protected]>
Sent: Wednesday, November 08, 2006 6:36 PM
Subject: Re: terminology wa Re: XML basics Re: LC model draft
draft-ietf-forces-model-07.txt


> All pieces of information that the ForCES protocol can manipulate are
> described in LFB Class definitions using the LFB components defined
> in the schema (currently called capability, attribute, and event,
> along with element properties.)
> Given the existence of documentation elements, there is no reason to
> use arbitrary XML in the definitions, and the schema does not permit
> arbitrary elements.
>
Ok so far but I am asking more.  If a CE wishes to access a piece of data by
itself (not as part of a larger structure) using PATH-DATA-TLV, then must that
piece of data be defined as an XML element as opposed to being defined as an XML
attribute?

This is fundamental to my understanding of how -model and -protocol link
together and I do not see it clearly stated.  s7.6 may or may not say this
depending on which of the many possible interpretations is given to the terms
'element' and 'identifier':-(

Thus s7.6 might be reworded as
   "The FE Model provides for the definition of LFB Classes.  Each LFB Class has
a globally unique identifier, assigned by IANA.  Each instance of a particular
LFB Class within an NE also has a unique identifier.  Data elements that can be
accessed by the protocol using a PATH-DATA-TLV are defined as XML elements and
each is assigned an identifier (using the XML attribute "elementID= ") that is
unique within an LFB Class.  The combination of LFB Class identifier, LFB
instance identifier and element identifier(s) is used by the protocol to
reference the LFB information in the protocol operations. "

Have I got it? ((skating over for the moment elementIDs in events and
structures)

Tom Petch

> (This may suggest to some a compatibility issue.  The idea is that if
> the schema is ever extended then old definitions will be compatible
> with the new schema, but new definitions will not be compatible with
> the old schema.  Given the need for semantic knowledge for anything
> making uses of LFB class definitions, this does not seem to be a problem.)
>
> Yours,
> Joel M. Halpern
>
> At 09:49 AM 11/8/2006, tom.petch wrote:
> >In general, most of what can be done in XML can be done by using XML
> >attributes
> >of XML elements or by using XML elements per se. So a second point is, I am
> >unclear in -model whether the intention is that all pieces of data
> >that a CE can
> >read or write are expressed as XML elements or are some of them XML
attributes
> >(of XML elements).  This has ramifications for identifiers and namespaces
> >and -protocol.