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Re: Intermediaries

From: Ricky Ho <riho@cisco.com>
Date: Fri, 05 Dec 2003 08:48:37 -0800
Message-Id: <>
To: "Cutler, Roger (RogerCutler)" <RogerCutler@chevrontexaco.com>, www-ws-arch@w3.org

Can we use messageID to determine whether this is the "SAME" message ?  In 
other words, all other modification is insignificant.

1) Intermediary isn't the endpoint so it doesn't generate new messages, so 
the message it send MUST have same messageID as some previous messages it 
2) Orchestration is the endpoint which produce or consume messages, so the 
message it send MUST have different messageID from previous received messages

Going back to your example, it is NOT up the B and C to interprete the 
changes made by I differently.  The decision is completely finalized by I.

Best regards,

At 09:44 AM 12/5/2003 -0600, Cutler, Roger (RogerCutler) wrote:

>Here is some text that expresses my understanding of the sense of some
>of the telcon conversation about intermediaries.  Please use, modify or
>ignor as seems appropriate.
>It is useful to draw a distinction between situations where messages are
>passed through intermediaries and choreographies.  The essential issue
>is that an intermediary passes along a message that is essentially, or
>functionally, the same as it received.  If, on the other hand, the
>purpose or function of the message is substantially changed one should
>consider the situation to be a choreography.  This cannot be defined,
>however, in an entirely rigorous or black and white way -- one person's
>intermediary may legitimately be considered a choreography by others.
>Note that since an intermediary can change the message, for example by
>encrypting it or by adding ancillary information, it remains a judgment
>call whether those changes are significant and functional.  In addition,
>whether a service that passes messages is considered an intermediary
>depends on participants in the entire chain of the message.  For
>example, if sender A sends messages through I, which modifies the
>messages, to receivers B and C, B might consider the modified message to
>be functionally unchanged whereas C might consider it to be different
>and take different action because of the modification.  In the first
>case I would be considered an intermediary, in the second it would not.
Received on Friday, 5 December 2003 11:49:02 UTC

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