ebxml-msg — archive

[System]

Marty: I agree with you that if the CPA template is missing communication endpoint information, then the missing information may have to be filled in by the parties through other configuration means before B2B exchange can take place. The sender must know the receiver's URL in order to send a message. The receiver, on the other hand, may not necessarily have to know the sender's return URL ahead of time. An implementation may want to provide this level of flexibility to improve scalability. For example, the ebXML registry grants read access to all clients. Why is it important for it to know a priori the communication URL of every client? The existing Messaging Service spec allows for supplementing endpoint information that is missing from the CPA. Consider the Sender element (under TraceHeader) described in section 8.5.2.1 (line 990): 8.5.2.1.2 Location element 1001 This element contains the URL of the Sender�s Message Service Handler. Unless there is another URL 1002 identified within the CPA or in MessageHeader (section 8.4.2), the recipient of the message uses the 1003 URL to send a message, when required that: 1004 � responds to an earlier message 1005 � acknowledges an earlier message 1006 � reports an error in an earlier message. 1007 This element seems usable by the sender to inform the receiver of its return URL, when the CPA installed at the receiver does not spell out the sender's communication URL. I am not advocating adding new elements to the message header at this point solely to enable a CPA template to be substituted for a complete CPA. However, I don't think we should remove mechanisms that are already in place in the message header (either in the PartyID under the From element, or in the Location under Sender in the TraceHeader element) to supplement information that may be missing from the CPA. Regards, -Arvola