When an UNBIND request is received by an SLU application program or is received by a PLU application program for which SONSCIP=YES is coded on the APPL definition statement, the SCIP exit routine is scheduled. The CID of the terminated session is provided in the exit parameter list. Because VTAM® automatically sends a positive response to the UNBIND, the application program needs only to clean up its representation of the session; no CLSDST or TERMSESS should be issued.

The exit parameter list provides the USERFLD field specified in the NIB when the session is established by OPNDST or OPNSEC. The USERFLD can be used by the application program to identify the session. A read-only RPL is also provided to the exit routine. The AREA field in the RPL points to a read-only copy of the UNBIND request. The RPL's RECLEN field contains the length of the request. The UNBIND SON code in the request indicates the reason for the session termination and can be used by the application program to determine what recovery action to take. UNBIND parameters are discussed in the section titled Session outage notification (SON) codes on UNBIND.

An SLU application program must have an SCIP exit routine. If a PLU application program does not have an SCIP exit routine or if SONSCIP=NO is coded on the APPL definition statement, the NSEXIT exit routine (if it exists) is scheduled with CLEANUP when UNBIND is received by the PLU application program; if the NSEXIT exit routine does not exist either, the LOSTERM exit routine is scheduled. See Table 1 for information on exit routine scheduling.