The messages that are exchanged between programs and services can be seen through TCP tunneling. This is particularly useful when you want to see the exact SOAP messages exchanged between the BPEL process service component flow and web services.

To monitor the SOAP messages, insert a software listener between your flow and the service. Your flow communicates with the listener (called a TCP tunnel) and the listener forwards your messages to the service, and displays them. Likewise, responses from the service are returned to the tunnel, which displays them and then forwards them back to the flow.

To view all the messages exchanged between the server and a web service, you need only a single TCP tunnel for synchronous services because all the pertinent messages are communicated in a single request and reply interaction with the service. For asynchronous services, you must set up two tunnels, one for the invocation of the service and another for the callback port of the flow.