Side Info Table Hierarchy 
Parameter values of the various side info tables take effect according to constellation. The following describes the two basic constellations.
- Source system is an SAP system
- R/2 is the source system
- R/3 is the source system
- Source system is a non-SAP system
Source system: SAP System
Here the source program can be distinguished as an ABAP program in R/2, or an ABAP program in R/3.
Source system: R/2
The hierarchy of the side info tables is as follows:
- R/2 is the target system:
A connection to the R/2 partner system is set up via the parameter values DEST, LU and TP in the XCOM table.
- R/3 or an external system is the target system:
- A connection is set up to the SAP gateway on the gateway platform via the parameter values DEST, LU and TP in the XCOM table.
- The connection to the target system is set up via the sideinfo table on the gateway platform. Parameter value I or E for the protocol type defines the target system.
Source system: R/3
The target is defined via the protocol type in the side info table:
C:
R/2 System
I:
R/3 System
E:
External system (start with
fork/exec, Remote Shell or rexec)
F:
Non-SAP program (started externally)
R:
Non-SAP program (started after being registered at the SAP Gateway)The hierarchy of the side info tables is as follows:
- A connection is set up to the SAP gateway on the gateway platform via the parameter values of the TXCOM table.
- R/2 is the target system:
The parameter values for LU and TP in TXCOM are ignored. You must define them in the sideinfo table of the SAP gateway.
- R/3 is the target system:
If TXCOM contains all the necessary parameters, you cannot access the sideinfo table.
If TXCOM does not contain all the necessary parameters, then those missing are read from sideinfo.
- An external system is the target system:
TXCOM must include protocol type E.
- The connection to the target is set up via the sideinfo file on the gateway platform. Parameter value C, I, E, F or R for the protocol type defines the target system.
Source system: Non-SAP System
The connection to the target is set up via the sideinfo file on the gateway platform. The parameter value for the protocol type defines the target:
C:
R/2 System
I:
R/3 System
E:
Non-SAP program (started by means of
fork/exec, remote shell or rexec)R:
Non-SAP program (started after being registered at the SAP Gateway)