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

Burdett, David wrote:
...
> There was a lot of debate as to whether ebXML Messaging should >require< 
> a CPA where I took the view that you can and should separate messaging 
> layer from "business process" layers and that it should be possible to 
> use the messaging layer without any pre-agreement being necessary 
> (although they are possible and sometimes desirable as I discuss later).
+
...
 > 3. The specification, ngotiation, and enforcement of agreements as in
 > ebXML should be possible, but as a layer on top.
 >>>>>>>>>
[DUANE] In a lot of ways,  I like the WSAG approach better where a CPA 
is not explicitly required for every message.  The WS provider still has 
the option of making a CPA ID a required parameter to use the WS interface.

> This means you should be able to do the following:
> 1. Discover information about a service (e.g. using WSDL) which should 
> include information about the additional SOAP features that the service 
> supports or requires (e.g. Reliable Messaging, use of signatures, 
> conversations and choreographies) - see more below.
>>>>>>>>
One missing component I would like to see is semantics.  David - do you 
think there is a way to leverage the semantics of UBL, CCTS for the WSAG?

  > 2. Use that information to send a message to the service that includes
> as features (i.e. SOAP headers), the necessary information for the 
> destination to determine what to do with the message
> 
> 3. The destination, when it receives the message, checks the SOAP 
> headers and other data in the message against its policies as 
> represented in the WSDL (or elsewhere) and decide if the message is OK 
> to process.
>>>>>>>

Doesn't WSCI provide the framework for determining message content?  I 
guess using WSCI is not a requirement of the WSAG however.  This sounds 
very similar to a working group in CEFACT called the Generic Business 
Message Header working group.

The flexability of the WSAG to not specifically require, yet still allow 
this where needed is nice.  I may be writing a chapter for a book on 
[SOAP | Web Services].  I may take this on as a challenge to show SOAP + 
WSDL working with an ebXML CPA.

Duane



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