Session level isolation
If VTAM® can isolate the error to a single session, an UNBIND request (usually with type code X'0E'— Recoverable LU Failure) is sent to both logical units in that session. The manner in which this session outage notification is presented to the application program depends on whether the application program is the primary or secondary logical unit; whether SCIP, NSEXIT, or LOSTERM exit routines were specified; and whether the SONSCIP parameter was used on the APPL definition statement. See Session outage notification for a description of these options.
SCIP exit routine provides a brief description of the potential UNBIND type codes.
VTAM also attempts to post any outstanding requests for the session with (RTNCD,FDB2)=(X'10',X'0E'). Depending on the error that caused the original outage, this posting might not always be possible.
The application program can attempt to reestablish the session after performing any specific user application cleanup procedures that might be necessary.