A calling system can be defined in the called system as a 'trusted system', using transaction SMT1. The called system is then referred to as the 'trusting system'.
Trusted ABAP systems can log on to other ABAP-based SAP systems without a password. This kind of trusting relationship between ABAP-based SAP systems has the following advantages:
You can set up multiple SAP systems as mutually trusting systems. When a trusted relationship is set up between two systems, the initiative comes from the called system (server system). The user of the calling system, who can execute RFC calls by means of a trusted relationship, has to be made known in the called system (trusted user).
Before a trusted system is defined, a destination has to be created for this trusted system in the trusting system. Also, the RFC users have to have the corresponding authorizations in the trusting system ( authorization object S_RFCACL). The authorization for the logged- on user in the trusting system can be checked in advance using the AUTHORITY_CHECK_TRUSTED_SYSTEM function module.
In a trusting relationship, the calling system (client system) has the role of the trusted system, and the called system (server system) has the role of the trusting system.
Example of creating a trusted relationship.