The image shows a diagram of an asynchronous interaction with a timeout occurring between a client BPEL process and a service BPEL process. The following actions take place:
The client BPEL process, which has a bpel.xml deployment descriptor, has a call service invoke activity, and a pick activity. The invoke activity sends its request to the service BPEL process by way of a valid WSDL partner link.
The service BPEL process, which also has a bpel.xml deployment descriptor, has a receive activity and an invoke activity. Its receive activity accepts the request from the client. Its invoke activity sends a response back to the client using the WSDL partner link.
The pick activity in the client BPEL process selects an action to perform, depending on whether the service BPEL process's response arrives in time. If the response does arrive in time, the callback branch performs a callback. If the message does not arrive in time, the timeout stops the activity.