OSI/AS Programming Manual

Parameter Structures
DDL Definitions
056783 Tandem Computers Incorporated A–15
ZAPS-DDL-PRES-CNTXT-RLIST is the presentation context definition result list,
indicating the acceptance or rejection of each of the presentation context definitions
proposed in the presentation context definition list. It is set in a presentation or ACSE
connect response through a call to APS_ASSOC_CONNECTRSP_. It can be retrieved
in a presentation or ACSE connect indication and confirm with a call to
APS_ASSOC_GETPARAM.
DEFINITION ZAPS-DDL-PRES-CNTXT-RLIST.
02 ZNUM-ELEMENTS TYPE ZAPS-DDL-INT1.
02 ZELEMENT OCCURS 16 TIMES.
03 ZRESULT TYPE ZAPS-DDL-INT1.
03 ZTS-NAME TYPE ZAPS-DDL-TRANSFER-SYN-NAME.
03 ZREASON TYPE ZAPS-DDL-INT1.
END
The following paragraphs explain how the fields in this structure are set by OSI/AS in
a connect indication, by your application in a connect response, and by OSI/AS in a
connect confirm.
In a connect indication: Because OSI/AS does not perform encoding on behalf of the
application, you must decide which of the proposed transfer syntax names will be
used in each presentation context. This approach differs from the approach specified
in the OSI standards, which expects the Presentation Layer to make the decision.
In the connect indication, OSI/AS sets the number of elements (ZNUM-ELEMENTS)
to the same number that appears in the presentation context definition list. For each
corresponding element in the presentation context definition list, OSI/AS sets the
following values in the presentation context definition result list:
ZRESULT, the result code, is set to ZAPS-VAL-CNTXT-RSLT-ACCEPT.
ZTS-NAME, the transfer syntax name, is not set.
ZREASON, the reason code, is set to ZAPS-VAL-CNTXT-RSN-NOVALUE.
For the ACSE presentation context, OSI/AS sets the the following values in the
presentation context definition result list:
ZRESULT is set to ZAPS-VAL-CNTXT-RSLT-ACCEPT.
ZTS-NAME is set to the value for ASN.1 basic encoding rules (BER).
ZREASON is set to ZAPS-VAL-CNTXT-RSN-NOVALUE.
For each element in the presentation context definition result list in the indication, you
must include a corresponding element in the response.
In a connect response: When you receive the presentation context definition list in a
presentation or ACSE connect indication, you must set the number of elements
(ZNUM-ELEMENTS) in the presentation context definition result list in your connect
response to the same number that appears in that structure in the connect indication.
Each element in the presentation context definition list has a corresponding element in