LU 6.2 capable application programs that omit the LOGON
exit routine have the PLU session establishment function performed
by VTAM®. VTAM's APPC support
accepts the following three types of session establishment requests
on behalf of the application program:
- CINITs that are the result of a prior APPCCMD CONTROL=ALLOC issued
by the local application program
- CINITs that result from VTAM's automatic activation of sessions
as the result of a CNOS request
- CINITs that contain an LU type of 6.2
No session establishment requests are accepted by VTAM's
APPC support other than those listed above.
Note: VTAM accepts
non-LU 6.2 session establishment requests, but they remain queued
until you issue a non-LU 6.2 macroinstruction to process the request.
Refer to
z/OS Communications Server: SNA Programming for the appropriate macroinstructions.
The application program must issue SETLOGON OPTCD=START
to allow VTAM to establish
sessions. The function provided by SETLOGON is still needed even though
the application program has no LOGON exit routine.
The set of session parameters used by VTAM in building the BIND are those contained
in the CINIT along with overrides of certain parameters. See BIND image and response for more information on what values
are used by VTAM.