Exception handling in synchronous proxy - web service scenario

Question

Hi Gurus,
I have a synchronous scenario in which SAP is sending a request via XI using SOAP and receiving a response back. As part of this scenario, I am consuming standard web service APIs provided by the third party.
Since, every request has to contain the connecting user id and password provided by the third party, I am sending/receiving messages without SOAP envelop (achieved by clicking 'Do not use SOAP envelope' checkbox in SOAP Receiver Communication Channel).
For this scenario, we are including the user id and password in the request message using XSLT mapping and the request number using simple message mapping.
The fault message of the web service is being mapped to the fault message created in XI under Fault Message Types.
The interface mapping page has got 3 tabs, one each for Request message mapping, Response message mapping and Fault message mapping.
When I trying to test a failure scenario by giving an incorrect request number(since this is the only input parameter in gthe request message apart from user id and password), it is throwing up "MAPPING">EXCEPTION_DURING_EXECUTE error.
Actually, for such requests, I am getting a proper fault response back from the third party which I can see in XI (in moni) as response to my request but when I am looking at the message in moni in SAP, I am only seeing "MAPPING">EXCEPTION_DURING_EXECUTE. Even I can see the exception in the trace section of my response in moni in XI.
My feeling is that the fault message mapping is not getting executed at all.
I also thought to do a 2:1 multimapping in which, the target side will contain the response message type created in XI but the source will contain two messages, i.e. Normal response message structure provided by third party and Fault message structure provided by third party but I am not sure whether this is possible without using BPM.
Please suggest the best way to resolve this issue.

Answer 1

The Fault message raised from 3rd party service, is structured as follow ??
HTTP/1.1 500 Internal Server Error
Content-Type: text/xml; charset="utf-8"
Content-Length: nnnn
<SOAP-ENV:Envelope
  xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/">
   <SOAP-ENV:Body>
       <SOAP-ENV:Fault>
           <faultcode>SOAP-ENV:Server</faultcode>
           <faultstring>Server Error</faultstring>
           <detail>
               <e:myfaultdetails xmlns:e="Some-URI">
                 <message>My application didn't work</message>
                 <errorcode>1001</errorcode>
               </e:myfaultdetails>
           </detail>
       </SOAP-ENV:Fault>
   </SOAP-ENV:Body>
</SOAP-ENV:Envelope>
Take a look here:
/people/jin.shin/blog/2007/05/21/handling-web-service-soap-fault-responses-in-sap-netweaver-xi
and to this standard document:
http://help.sap.com/saphelp_nwpi711/helpdata/en/48/5946db5f693912e10000000a42189b/content.htm