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RE: Role of intermediary

From: Williams, Stuart <skw@hplb.hpl.hp.com>
Date: Fri, 26 Jan 2001 15:18:15 -0000
Message-ID: <5E13A1874524D411A876006008CD059F19215A@0-mail-1.hpl.hp.com>
To: "'marwan sabbouh'" <ms@mitre.org>
Cc: "'Lerner, Michah, ALSVC'" <michah@att.com>, "'xml-dist-app@w3.org'" <xml-dist-app@w3.org>
> -----Original Message-----
> From: marwan sabbouh [mailto:ms@mitre.org]
> Sent: 25 January 2001 15:55
>
> Hi Stuart;
> 
> I see where you are heading with this.  Am I correct to say that you
> view  the intermediary as the processing element that apply some sort of
> transformation to that incoming message?  Does the requirement 
> specification  support this notion?  Please don't get me wrong, I am not
> advocating one way or another.  I'm just trying to get the definition
> down.
> 
> Marwan

Hi Marwan,

I think many of us are just trying to get the definition down too... I think
that I too am more in the asking questions mode than asserting answers. So
this is merely one persons viewpoint.

> Am I correct to say that you view  the intermediary as the processing
element that apply some sort of
> transformation to that incoming message? 

Mostly yes... although I think I could also have multiple distinct
viewpoints. I tend to think of an XP Module as having both syntactic
elements (the XP Blocks) with their semantics and a set of rules that govern
any processing of those blocks. One could view a message passing through
entities that applied the rules of a given XP module to the XP blocks
associated with that XP module. Those entities could exist anywhere between
the sending and receiving XP processors. So an intermediary would be a
container (an execution environment) for those entities.

Hopefully that gets the first part. The second is about transformation of
the message. To some extent here it depends very much on what one regards as
a message. Some folks have postulated the notion of an intermediary that
could sign a message (eg. endorse a purchase order on it's way out of a
business). Does the addition of the signature count as a transformation? I
think so. One could imagine another sort of intermediary that converted
images attached from TIFF to JPEG. I think that too is a transformation...

> Does the requirement specification support this notion?

I think there are motivating use cases either articulated or being
formulated. The term "Processing Intermediaries" is introduced in the
requirements document, so I would assume that there is some desire on the
part of those that introduced the term that intermediaries do some
processing.

Best regards

Stuart
Received on Friday, 26 January 2001 10:18:44 GMT

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