[ebxml-cppa] AckRequested and DeliveryReceiptRequested

[Arvola Chan <arvola@tibco.com>]

The MSG spec defines these elements as follows:

 <element name="AckRequested">
  <complexType>
   <attribute ref="tns:id"/>
   <attribute ref="tns:version" use="required"/>
   <attribute ref="soap:mustUnderstand" use="required"/>
   <attribute ref="soap:actor"
default="urn:oasis:names:tc:ebxml-msg:service:toPartyMSH"/>
   <attribute name="signed" type="boolean"/>
  </complexType>
 </element>

 <element name="DeliveryReceiptRequested">
  <complexType>
   <attribute ref="tns:id"/>
   <attribute ref="tns:version" use="required"/>
   <attribute ref="soap:mustUnderstand" use="required"/>
   <attribute name="signed" type="boolean"/>
  </complexType>
 </element>

These elements determines whether the receiving MSH should return a (signed
or unsigned) Acknowledgment / DeliveryReceipt. I think we should add
corresponding AckRequested and DeliveryReceiptRequested elements (minus the
tns:id, tns:version, soap:mustUnderstand attributes) under DeliveryChannel
to guide the construction of the above elements during the packaging of an
ebXML message. In other words, I don't think that the decision to ask for a
signed Acknowledgment or DeliveryReceipt should be derived from the
NonRepudiation element (under DocExchange). Instead, it should be based on
the corresponding AckRequested and DeliveryReceiptRequested elements in the
CPA.

Marty has previously indicated that the Characteristics element provides for
overriding of BPSS attributes only. Perhaps we can replace Characteristics
with BPCharacteristics and MSGCharacteristics, and keep the AckRequested and
DeliveryReceiptRequested elements under MSGCharacteristics. In addition,
MSGCharacteristics should carry a duplicateElimination attribute to guide
the construction of the QualityOfServiceInfo element within MessageHeader
which also has a duplicateElimination attribute.

-Arvola