Programming under Various Constellations 

Various constellations are possible for communication between programs within the SAP world (R/2 and R/3), and between SAP programs and external programs.

Communication is based on various protocols, depending on constellation:

If the R/2 host is a BS2000 System, the SAP Gateway runs under DCAM in BS2000 and communicates with R/3 or an external program on the basis of TCP/IP.

The SAP Gateway is always necessary for communication via one of the interfaces implemented by SAP.

The individual constellations are described in the following.

R/3 « R/3

R/3 « R/2 (MVS/VSE)

R/3 « R/2 (BS2000)

R/3 « Non-SAP Program

R/2 « R/2

R/2 « Non-SAP Program

C Program « C Program