To install VTAM® exit routines you assemble and link-edit the exits.

Follow these steps to install the appropriate VTAM exits:

1. Assemble the exits.
2. Link-edit the exits to the appropriate VTAM library as indicated in Table 1.

   Table 1. Libraries for VTAM exit routines

   Exit routine	MVS™ library
   Session management exit routine	SYS1.VTAMLIB
   Virtual route selection exit routine	SYS1.VTAMLIB
   Virtual route pacing window size calculation exit routine	SYS1.VTAMLIB
   Configuration services XID exit routine	SYS1.VTAMLIB
   Selection of definitions for dependent LUs exit routine	SYS1.VTAMLIB
   USERVAR exit routine	SYS1.VTAMLIB
   Command verification exit routine	SYS1.VTAMLIB
   Directory services management exit routine	SYS1.VTAMLIB
   Generic resource resolution exit routine	SYS1.VTAMLIB
   Performance monitor exit routine	SYS1.VTAMLIB
   Session accounting exit routine	SYS1.LPALIB1
   Session authorization exit routine	SYS1.LPALIB1
   Note: If you place your user-written exit in SYS1.LPALIB, re-IPL to reformat the link-pack area. For details, see z/OS MVS Initialization and Tuning Reference.

   Link-edit VTAM exits before starting VTAM. Link-editing after VTAM is started might lead to subsequent load errors during exit activation. The names of the user-written exits must be those shown in Table 2 unless you have provided an alternate exit or a multiple exit using the MODIFY EXIT command. For a discussion of this command, see z/OS Communications Server: SNA Operation.

   Table 2. VTAM exit names for exit routines

   Exit routine	VTAM module name
   Session management exit routine	ISTEXCAA
   Virtual route selection exit routine	ISTEXCVR
   Virtual route pacing window size calculation exit routine	ISTPUCWC
   Configuration services XID exit routine	ISTEXCCS
   Selection of definitions for dependent LUs exit routine	ISTEXCSD
   Command verification exit routine	ISTCMMND
   USERVAR exit routine	ISTEXCUV
   Directory services management exit routine	ISTEXCDM
   Performance monitor exit routine	ISTEXCPM
   Session accounting exit routine	ISTAUCAG
   Session authorization exit routine	ISTAUCAT
   Generic resource resolution exit routine	ISTEXCGR