SESSIONC macroinstruction with CONTROL=BIND

The SESSIONC macroinstruction with CONTROL=BIND is used to reject a BIND request from a PLU if the application program does not wish to establish the session. For example, if the BIND request is non-negotiable and the session parameters are unacceptable, the application program would have to reject the BIND.

The SESSIONC macroinstruction uses the RPL and, optionally, an NIB to identify the BIND to be rejected. If the RPL contains a CID, the CID uniquely identifies the BIND to be rejected. (The CID can be obtained from the SCIP exit routine parameter list when the SCIP exit is scheduled with the BIND request.) If the RPL points to an NIB and the application program is capable of parallel sessions (PARSESS=YES is coded on the APPL definition statement) and the NIBCID field is not zero, then the CID identifies the BIND to be rejected. Otherwise, the NIBSYM field contains the name of the PLU from which the BIND came.

The name supplied can be network-qualified by using NIBNET if PARMS=(NQNAMES=YES) is specified on the ACB macroinstruction. If there is more than one BIND outstanding from the named PLU, the oldest is rejected.

If the queued BIND to be rejected cannot be found (for example, if the PLU sent UNBIND that purged the BIND), SESSIONC is posted with (RTNCD,FDB2)=(X'14',X'13') if a CID is specified, or with (RTNCD,FDB2)=(X'14',X'60') if only a name is specified.

The PLU name in the BIND request presented to the application program can be either the network name of the PLU or an uninterpreted name as follows:

If the PLU is a VTAM® application program whose APPL definition statement includes either a network name or an ACBNAME name, and if this program issues CLSDST OPTCD=PASS to initiate the session, the network name is used in the BIND.
If SIMLOGON, OPNDST OPTCD=ACQUIRE, or automatic logon is used to initiate the session, the network name is used in the BIND.
If the SLU initiated the session (for example, by issuing REQSESS, INIT-SELF, or LOGON), the uninterpreted name is used in the BIND. The same name that is used in the original session-initiation request from the SLU is returned in the BIND.

When the BIND flows in the network, the name fields (NS_PLU and NS_SLU) can be network-qualified. As the BIND is presented to the application, this name, if it were network qualified, is changed from network-qualified to an 8-byte name. The 8-byte name can differ from the LU portion of the network-qualified name. If it does, name translation has occurred. For details of the names available to the application, see Table 1 and Table 1.

Use of the network name, as opposed to the ACBNAME, in the BIND permits the SLU to unambiguously relate a BIND to a particular PLU. The network name can also be used by the SLU to reinitiate a session (for example, after a session outage), even if the original session is initiated by the PLU or a third party.

The SSENSEO, SSENSMO, and USENSEO fields of the RPL specify the sense data to be returned in the BIND response when the request is rejected.