Subject: Re: A discussion of metadata in ForCES

From: Gamil Cain <[email-masked]>
Date: Mon, 27 Oct 2003 12:36:17 -0500

Alan et. all,

My collegue (David Putzolu) forwarded me your posting on metadata and I had
a few comments, questions.  In general, it seems to be good text and does a
good job of distinguishing between the various types of metadata and
establishing common terminology.  The only question I have is in reference
to the following paragraph:

 " In contrast, as one of the goals of ForCES is to facilitate inter-
   vendor communication, External metadata is within the scope of
   ForCES.  The group should create definitions of, and standards for,
   External metadata which permit different vendor implementations of
   devices to communicate metadata."

My question is of a similar vein as Lily's.  It seems to me that by
defining external metadata (as the text above suggests) ForCES may need to
crack open the FE (which I thought was viewed as a black box, from a ForCES
perspective).  So is this really in scope for ForCES or should ForCES just
assume that there is a mechanism for transporting information across FEs?

Taking from your response to Lily's questions:

"We need to use common terminology when creating the model, and dealing
with LFB's.  I do not expect anyone to implement the LFB's as defined in
the model, so there should be no requirement that LFB implementations are
inter-operable.

However, all LFB's exist within the model, so in the model, the LFB's and
any metadata they use MUST be "compatible".  If the metadata used in the
model is different from LFB to LFB, then those LFB's cannot be used to
build a self-consistent model."

So what's the difference between being "interoperable" and "compatible".  I
view them as one and the same, in this context.  And I'm still not sure how
you go about defining metadata (in ForCES) without opening up the FE "black-
box" and making some judgment on what's going on inside that FE.  Is the FE
a black box or not?  I think if ForCES goes to the point of specifying
metadata, the FE (to a certain extent) is no longer a black box.

I have another concern that there could be overlap, and possibly
incompatability, between metadata definition work done within ForCES and
work being done within NPF of a similar nature.

Appreciate your input/clarification on this.

Regards,

Gamil Cain
Software Architect
Intel Research & Development
916.356.9153
mailto:[email-masked]

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From: Alan DeKok <[email-masked]>
Date: Mon, 27 Oct 2003 13:41:01 -0500

Gamil Cain wrote:
> perspective).

  The model document already "opens" the FE, if only from a
modelling/black-box point of view.

>  So is this really in scope for ForCES or should ForCES just

  The FE's must communicate, so any information which is exchanged
between FE's must be in a mutually understandable format.  This means
well-defined protocols, and metadata.  Defining the terms we use is
therefore within the scope of ForCES.

> So what's the difference between being "interoperable" and "compatible".

  Interoperable means that they communicate & interpret metadata
programmatically.  The systems are "compatible" on both conceptual, and
on physical levels.

  Compatible means that the *concepts* of metadata are the same, but the
systems may not communicate that metadata directly.

  There is overlap between the two terms, but I'm not sure that they're
identical in meaning.  My response quoted above was meant to show that
there may be things in the model which are not in the physical system.
The physical system does not have to inter-operate using the concepts,
but the concepts MUST be compatible from the perspective of fulfilling
the conceptual goals.

>  And I'm still not sure how

  As I said, the model document already "opens" the FE black box.  My
document adds no more requirements or restrictions on ForCES.  Instead,
I'm simply trying to define the terms we use in ForCES, as there has
historically been controversy and confusion surrounding the word
"metadata".

> work being done within NPF of a similar nature.

  Most companies involved in NPF are also involved in IETF.  In some
cases, it's the same person in NPF & ForCES.  While I'm not involved in
NPF, I was involved historically, and I still follow it.  The person at
IDT who is involved sits near me, and we coordinate our efforts.

  Alan DeKok.