For RACF® callable services, the SAF callable services router performs a function similar to that of the SAF router. The SAF callable services router installation exit IRRSXT00 can be used to add to or replace the functions provided by RACF's callable services for z/OS UNIX System Services.

IRRSXT00 is called each time a RACF callable service for z/OS UNIX System Services is invoked. The exit is called both before and after RACF is called. When IRRSXT00 is called before RACF, the exit can request that RACF not be called. For more information, refer to z/OS Security Server RACF Callable Services.