This topic describes VTAM® installation-wide exit routines that control session management, virtual route selection, virtual route pacing window size, session accounting, session authorization, dynamic definition of switched connections, dynamic definition of dependent logical units (LUs), command verification, USERVAR processing, directory services management, generic resource resolution, and performance monitoring.

This topic also provides information for installing VTAM installation-wide exit routines, and describes the roles of the DISPLAY and MODIFY commands for displaying, activating, deactivating, and replacing the exit routines described throughout the SNA Customization information.