I'm working on one Synchronous scenario where REST sender with Polling and Proxy Receiver(ECC).
Message Protocol

OAuth2.0-Client Credentials Authentication

Quality Of service

>I have created sender structure in XSD and imported as external definition as the source has some special characters in payload.
>I have one WSDL imported(ECC), in that both request and response structures are maintained.
>I have one DT for receiving the response sent from ECC.
>Two MM's are maintained.
As we know in quality of service exactly once or exactly once in order the sender system cannot hold the response sent from ECC.
Can any one guide me how to achieve this scenario and how many SI and how many OM should be maintained or any other possibility.
Thanks