SAP-CPI-C development libraries based on the communications protocol SNA-LU6.2 have the name cpicslib and a platform-specific extension.

The CPI-C functions of cpicslib are mapped directly to LU6.2 level.

For communication with an R/3 System, you need a communications subsystem on both computers and the SAP Gateway on the R/3 computer.

Depending on your requirements, you can alternatively use the manufacturer-specific interface (for example, LU6.2/APPC) directly for communication with the R/2 host.

In both cases the application program communicates via the communications subsystem with the ABAP program on the R/2 host (without the SAP Gateway).