Usage Scenarios for the RFC Adapter and Restrictions
The RFC adapter maps the following RFC calls to XML messages and the other way around:
- Synchronous RFC calls (sRFCs) in messages with quality of service Best Effort (BE)
- Transactional RFC calls (tRFCs) in messages with quality of service Exactly Once (EO)
- The receiver RFC adapter can also process messages with quality of service Exactly Once In Order (EOIO). They are mapped to transactional RFC calls (tRFC).
See: Quality of Service
Usage Scenarios
The following three scenarios are possible when using the RFC adapter and the Integration Engine:

SAP System to SAP NetWeaver Application Server
- Register the RFC server program of the RFC adapter at the gateway of the SAP system.
- Change the RFC destination in the SAP system to reference the registered RFC adapter.
- Provide mappings for request and response messages.
- Establish logical and technical routing.
SAP NetWeaver Application Server to SAP System
- Provide mappings for request and response messages.
- Establish logical and technical routing.
SAP System to SAP System
- Register the RFC server program of the RFC adapter at the gateway of the SAP system.
- Change the RFC destination in the SAP system to reference the registered RFC adapter.
- Provide mappings for request and response messages.
- Establish logical and technical routing.
Restrictions
Note the following constraints:
- There is no transactional context for more than one RFC call for each LUW (Logical Unit of Work).
- SAPGUI, callbacks, and qRFC are not available.
- Receiver adapters only support external RFC servers that register themselves with an Gateway.
You cannot start external RFC servers.
- The context in the called system is not kept open over multiple calls (calls are stateless; there is no session).
- Only the payload of a received message is evaluated. Additional attachments are ignored and not forwarded.
- The receiver adapter can only process valid RFC XML documents, for example, those generated by the sender adapter or by the SAP JCo.
- You cannot use additional XML elements such as XML namespaces (xmlns).
- The sender adapter only supports function modules with at least one parameter (import, export, changing, or tables).
- Unicode and non-Unicode systems are supported. MDMP systems are not supported.
- The RFC metadata repository must be compatible with the sender and receivers systems with respect to Unicode. A Unicode sender or receiver system must have a Unicode RFC metadata repository. A non-Unicode sender or receiver system must have a non-Unicode RFC metadata repository.