The image shows a diagram of an asynchronous interaction between a client BPEL process and a service BPEL process. The following actions take place:

1. The client BPEL process has an invoke activity that defines a call service. This process also has a get response receive activity.

2. The call service invoke activity sends a request, using the WSDL partner link, to the service BPEL process. The WSDL partner link defines the interaction.

3. The service BPEL process has a receive activity and an invoke activity. Its receive activity receives the client's request, which in turn starts its invoke activity.

4. The service BPEL process's invoke activity sends the response back to the Get response receive activity of the client BPEL process, using the WSLD partner link.