LOSTERM reason codes

The following section describes the different reason codes that are found in register 1.
Reason code
Meaning
0 (X'00')
Reserved.
4 (X'04')
Reserved.
8 (X'08')
Reserved.
12 (X'0C')
Session has been terminated; immediate recovery is unlikely. The application program must issue CLSDST if it has not already done so. The cause of the session termination might preclude the session from being reestablished immediately; for example, the VTAM® operator might have deactivated the LU or the LU might have had an unrecoverable failure (for example, an abend).

For a list of possible causes of reason code 12, see Session outage notification (SON) codes on UNBIND.

As discussed in Establishing and terminating sessions with logical units, some of the types of session outages that cause it are reported instead through an SCIP exit routine (if SONSCIP=YES on the APPL definition statement) or otherwise through an NSEXIT routine (if one exists).

16 (X'10')
The session has been terminated. This reason code is reported immediately after, and only after, reason code 24 (unless CLSDST has been issued). The application program can try to reinitiate the session, for example, by issuing SIMLOGON or OPNDST OPTCD=ACQUIRE; however, the application program must issue CLSDST if it has not already done so.

If the LU has a controlling APPL, that is, if the original session is a result of a LOGAPPL parameter on a definition statement, or of a VARY LOGON command, VTAM attempts to reestablish the session by scheduling the LOGON exit.

Note: Once CLSDST has been issued, session initiation is subject to the normal rules. Therefore, if another LU has a queued session with the LU, the new session requested by the application program whose LOSTERM exit routine is invoked cannot be immediately established.

As discussed in Establishing and terminating sessions with logical units, many of the types of session outages that cause it are reported instead through an SCIP exit routine (if SONSCIP=YES on the APPL definition statement) or otherwise through an NSEXIT exit routine (if one exists).

20 (X'14')
A CTERM Forced request has been received. Perhaps the LU issued a Terminate Forced request, using TERMSESS OPTCD=UNCOND, for example. For a list of possible causes of reason code 20, see Session outage notification (SON) codes on UNBIND. The application program must issue CLSDST. When this completes, the application program can attempt to reinitiate the session.
24 (X'18')
The session has been terminated. The LOSTERM exit routine is immediately rescheduled with reason code 16 for this session. (See the preceding description of reason code 16.) The application program can issue CLSDST at this time, which in turn might cancel the execution of the LOSTERM exit routine with reason code 16. The session outage can instead be reported through an SCIP or NSEXIT exit routine as described under reason code 16.
28 (X'1C')
Reserved.
32 (X'20')
A CTERM Conditional request has been received. Perhaps the LU issued a Terminate Orderly request, using TERMSESS OPTCD=COND, for example. For a list of possible causes of reason code 32, see Session outage notification (SON) codes on UNBIND. The application program can issue CLSDST at any time. The interpretation of the receipt of CTERM Conditional is not defined by SNA or VTAM.
36 (X'24')
Received request or response units for this session have been discarded because of a lack of buffer space. The session has not been terminated, but session data recovery procedures are required (for example, CLEAR, SDT, and STSN as described in Communicating with logical units). This reason code can be reported to either a PLU or SLU application program. For further details, see the description of (RTNCD,FDB2)=(X'10',X'0F') in Return codes and sense fields for RPL-based macroinstructions.
44 (X'2C')
A cross-memory macroinstruction request failure has occurred. VTAM attempted to SUSPEND or RESUME the execution thread of the requestor, but the operation was not successful, possibly because the cross-memory address space has failed. The user RPL (pointed to by Word 2 of the exit parameter list) contains return code and feedback information describing the failures, but VTAM cannot perform normal completion notification. The RPL is now available for reuse.
48 (X'30')
A CLEANUP RU has been received. No NSEXIT is available to issue the CLSDST macroinstruction. VTAM will close the session.
Note: For any of the LOSTERM reason codes that require or recommend a CLSDST macroinstruction, do not issue a second CLSDST if one has been issued for the same session, but possibly for a different reason.