The destination parameter displays an entry in the RFCDES table (which is defined with transaction SM59). This entry contains all necessary parameters to connect to and log in the destination system.

You can use RFC between two SAP systems.

By using the RFC Library (RFC API), you can also use the functions of the RFC between an SAP system and a C program on different platforms. It is of no significance to the caller whether the remote function is provided in an SAP System or in a C program.

RFC frees the ABAP programmer from having to program his own communications routines. When you make an RFC call, the RFC interface takes care of:

· Converting all parameter data to the representation needed in the remote system. This includes character string conversions, and any hardware-dependent conversions needed (for example, integer, floating point). All ABAP data types are supported.

· Calling the communication routines needed to talk to the remote system.

· Handling communications errors, and notifying the caller, if desired. (The caller requests notification using the EXCEPTIONS parameter of the CALL FUNCTION statement.)

The RFC interface is effectively invisible to the ABAP programmer. Processing for calling remote programs is built into the CALL FUNCTION statement. Processing for being called is generated automatically (in the form of an RFC stub) for every function module registered as remote. This stub serves as an interface between the calling program and the function module.

A distinction is made between an RFC client and RFC server. RFC client is the instance that calls up the Remote Function Call to execute the function that is provided by an RFC server. In the following, the functions that can be executed remotely will be called RFC functions and the functions provided via RFC API will be called RFC calls.