The image shows a diagram of a synchronous interaction between two BPEL processes. The following actions take place:
The first BPEL process has an invoke activity that defines a call service.
The call service invoke activity sends its request to the second BPEL process, through a WSDL client partner link. The WSDL client partner link defines the interaction.
The second BPEL process accepts the request by using a receive activity.
The second BPEL process then uses a reply activity to send a response back to the first BPEL process, by way of the WSDL client partner link.