RE: [ebxml-msg] [Fwd: Some AS4 queries]

- The spec states that Signal Msg cannot have body. How is bundled msg handled ? Is it thru attachments ? Or does this constraint apply to a pure Signal Message ?

<JD> only “pure” signal message are supposed to NOT have a body. But the ebMS3 spec allows for some (limited) bundling of signals over other messages (see 5.2.4) and AS4 does not restrict this.

- If a msg has to be retried, then is it necessary to again bundle the same user msg, errors etc as original ?

<JD> No. The retry requirement (optional in AS4) only concerns the User message for which a Receipt was expected.

- Does the MSH implementation need to wait for the actual backend service to initiate a pull to the MSH or can it send the pull signal message on its own based on some agreements ?

<JD> can send the pull signal message on its own. This is an implementation choice and/or agreement choice. In fact, Fujitsu AS4 prototype allows for this.

- How is the identity of the sender determined from a signal message. From the WSS credentials ?

<JD> yes – when a Receipt needs be authenticated, it has to be signed. Since it is always associated with a User message, the sender of the Receipt is the “to” party of the User message. If necessary this only needs be confirmed with a signature. A PullSignal is originating more from an MSH than from a back-end sender. It is a low-level mechanism that has to be authorized for the particular channel it is pulling from, and does not need to be associated with a particular sender (several of these could share the same MSH and the same pull channel: the pulled message will be dispatched based on its “to” party). However an implementation could decide to do “pulling on demand” from a Sender. In that case, it is up to the implementation to authenticate the back-end sender , and associate it with the right pull channel (i.e. associate it with the right credentials for authorizing the pull on this channel)

- Msg delivery : In a bundled msg, should we assume that an eb:Receipt for a UserMsg means that even the errors/receipts are delivered ? Similarly if the MSH returns error that the User Msg is not delivered, then is the error also not delivered ?

<JD> At this point, no: the Receipt is only for the User message: it only identifies one MessageID value. Now, Several Receipts could be bundled in the coming Part 2 specification.

- Is there a One-One correspondence with User Msg Headers and the number of attachments or can there be more attachments than the headers.

<JD> There can be as many attachments as needed, each one referred to by an eb:partInfo element inside a single PayloadInfo element, for the same User message. So I guess the answer is: more attachments than [UserMessage] headers.

- Can there be multiple payloads for a User Msg Header ? What I wanted to know is how can partners send multiple messages in one User Msg e.g. can multiple quotes be sent as one user message ?

<JD> Yes. Multiple payloads, in either the soap Body, or as attachments, or as both.

- The ebMS speaks about a PullAndPull MEP. Does AS4 support this ?

<JD> PullAndPull is a two-way MEP (i.e. two User messages in opposite directions). At this point, AS4 only puts requirements to support One-way MEPs. You can of course emulate this using two One-way pull in opposite directions. But AS4 does not require support for two-way MEPs (although a conforming ebMS3 implementation used underneath would support this)

- Finally can we have some more sample messages covering some of these scenarios ? So we know how they look on the wire.

<JD> Acknowledged.

jacques

ebxml-msg message