Re: Layers in the WSA (was RE: [Fwd: UN/CEFACT TMG Releases e-Busines s Architecture Technical Specification for Public Review])

Champion, Mike wrote:
=
> Roger raises a very important point, IMHO. Does anyone who is involved in
> ebXML(or any other company/ organization who has this view of the world)
> want to make a case for the WSA conception of a messaging layer  having to
> understand and enforce business-level rules? 
 >>>>>>
I will tackle this one.  The text is probably not clear enough in our 
(UN/CEFACT) spec and we will address this during our face to face in 
early March.

What the messaging layer must do it provide enforcement via a 
gatekeeping functionality (an explicit tie-in to the Business Agreement 
between the sender and the receiver).  Any ebXML that arrives asserts 
that it exists as "part" of a business relationship.  It does this by 
asserting a unique identifier to an XML representation of that Business 
Agreement called a CPA.  The messaging layer can access an API to verify 
if that CPA ID is valid.

Furthermore,  since any single business relationship may involve several 
concurrent threads of a business process (ie - procurement), the 
incoming message must specify a Conversation ID, an assertation that it 
is one message belonging to a specific choreography of messages (thread?).

WSDL + SOAP do not have this functionality explicitly required, however 
that would not stop someone from implementing it by requiring that tie 
in as one of the required parameters. Therefore, WSDL + SOAP can provide 
this.  It is conceivable that someone could implement a WSDL/SOAP WS 
that had a tie in to an ebXML CPA instance.

This is what was meant by the statement in the architecture document. 
We obviously may need to re-visit this sentence to see if we need to 
clarify it.   Please also keep in mind that the UN/CEFACT architecture 
is not ebXML specifc.  It is not dependant on ebXML components being 
used and actually presumes that WSDL + SOAP may be an underlying 
implementation strategy.  Therefore, we (UN/CEFACT eBusiness 
Architecture Working Group) need to make sure we get this right.

> It seems a bit like asking IP
> to understand HTTP.  On the other hand, maybe our textbook notions of
> protocol layering are not holding up in the Real World, e.g. firewalls
> arguably *should* understand IP, TCP, HTTP, SOAP, SAML, WS-Security, etc.
> and their interrelationships.  
>>>>>>>>>>>
This was driven out of a set of business requirements collected by over 
2000 contributors around the globe.  The messaging layer does not need 
to understand what the layers up the stack are doing, just be capable of 
enforcing those rules of engagement.  Therefore,  a transport level 
acknowledgement should not to be construed as a business acceptance of 
the message etc etc.

Duane Nickull
-
VP Strategic Relations,
Technologies Evangelist
XML Global Technologies
****************************
ebXML software downloads - http://www.xmlglobal.com/prod/

Received on Wednesday, 12 February 2003 16:40:32 UTC