RE: Application Headers

["Burdett, David" <david.burdett@commerceone.com>]

Chris

Actually, I think there are two cases here:
1. Additional data that needs to be understood by the MSH, and
2. Additional data that needs to be understood by the application.

I guess the former is covered by the wildcard element within the header
element, and the latter is the responsibility of the application.

Does this mean that we need to:
1. Include a mustUnderstand on the wildcard element?
2. Remove the mustUnderstand on the ApplicationHeaders

There are also issues around saying a MSH mustUnderstand the extensions in
that which MSH mustUnderstand it when a message is going through several
hops.

So perhaps we should an optional mustUnderstand to the header element with a
semantic that the To Party MSH is the MSH that must understand it, and to
the Routing Header which is that the receiving MSH (which may be an
intermediate MSH) must understand it.

For applicationHeaders, I think we should perhaps remove the mustUnderstand
and just require the MSH to make the data available to an application that
wants it. If the receiving application does not ask for it or cannot
understand it, then it is an application not a message service problem.

Thoughts?

David
-----Original Message-----
From: Christopher Ferris [mailto:chris.ferris@east.sun.com]
Sent: Friday, January 05, 2001 7:20 AM
To: Burdett, David
Cc: ebXML Transport (E-mail)
Subject: Re: Application Headers


David,

Well, there are two aspects to this... 
1) the receiving "application" MUST be capable of processing the
namespace qualified application headers that are qualified with
a mustUnderstand=true
2) the receiving MSH MUST be capable of forwarding/providing
the namespace qualified application headers that are qualified with
a mustUnderstand=true to the receiving application

In either case there needs to be an exception/error reported.

However, since these are "application" headers, the "application"
needs to be notified... Hmmm... we may have a layering issue
to deal with here...

Chris


"Burdett, David" wrote:
> 
> Lines 841-845 say ...
> 
> >>>An ApplicationHeaders element that has a mustUnderstand set to a value
of
> true means that a receiving MSH MUST be capable of understanding the
meaning
> of the namespace-qualified element content. If the content is not
> understood, the receiving MSH MUST respond with a message that includes an
> errorCode of NotSupported in an Error element as defined in section
8.8.<<<
> 
> I don't think that the MSH must understand the elements. It only needs to
> recognize the namespace qualified elements and know that it has an
> application that can handle them.
> 
> Thoughts?
> 
> David
> 
> Solution Strategy, Commerce One
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