The MEP and the operation depends on the SOAP request. From the defined SOAP acion in the SOAP header (WSA-Addressing) or if it is not present from the SOAP action in the HTTP request, the operation to execute must be identified.
That's why on the initialization of an SU, the corresponding WSDL must be read to create a list containing the available operations and the corresponding MEP which be stored in the memory. On each request, the operation must be retrieved in the list from the soap action. (Currently the WSDL is read on each request to retrieve the operation, the MEP is not taken into account).