RFC and programming information for RFC client/server programs can be summarized as follows:
An RFC connection is always initiated by an RFC client program.
An RFC connection is always built up in two steps:
Connection from an RFC client to the Gateway
Connection from the Gateway to an RFC server
There are different ways of starting or connecting to an RFC server program:
An RFC server program can be registered at an Gateway. The program waits for RFC requests from SAP systems.
The registered server is the standard method for connecting an RFC server.
You can start an RFC server program via the Gateway or the currently running application server.
Starting the RFC server via an application server is not recommended if you are expecting frequent calls on this server.
For program start-up options while establishing an RFC connection, see