When more than one region in a network has MAI-OC sessions with the same set of target applications, you should assign a unique set of MAI-OC LU names to each region. This associates the names used by each region with the region in which that region is executing, and avoids VTAM definition conflicts when attempting to start cross-region sessions.
The other advantage of assigning each region its own set of MAI-OC LU names is that it allows added control over which regions can establish MAI-OC sessions with which subsystems.