You can use the RFC interface for communication between SAP systems and between SAP systems and external systems. SAP offers several interfaces that are based on RFC, such as Application Link Enabling (ALE), Business Application Programming Interfaces (BAPIs), and RFC function modules.
Applications can use RFC to call SAP function modules located in other systems. The interface works as follows:
An ABAP program can call a remote function with the statement CALL FUNCTION... DESTINATION. The DESTINATION parameter indicates the system where the function called is located. This function module must be an ABAP function module, and must be flagged as RFC-enabled in the Function Builder.
· Remote functions can be called either synchronously or asynchronously.
· Remote debugging is possible for connections where an SAP system is the target system.
If one of the communication partners is not an ABAP program, it must be programmed as an RFC communication partner. The SAP system is delivered with the RFC-API (Application Programming Interface). You can use this library in external systems to develop external RFC-enabled programs that can communicate with SAP Systems.
The RFC API is also known as the RFC Library (file name librfc<xx>.dll).
You must take various security measures when you use RFC connections in your SAP system. The following sections give you more details of these measures: