Our system received asynchronous callbacks from B using our own custom protocol that was similar to HTTP. When we decided to switch to SOAP for messaging, we also changed the transport to HTTP. HTTP uses a request-response method of transmission, whereas our systems also require a solicit-response model. I posted about this in the Axis User list, but got no response. See my message and my solution at http://marc.theaimsgroup.com/?l=axis-user&m=101430720610385&w=2
cheers,
Simon
