OSI/AS Management Programming Manual

Glossary
Glossary-6 056785 Tandem Computers Incorporated
Data communications standard definitions. In DSM, the set of declarations provided by
Tandem for use in all management programs that manage or retrieve event messages
from Tandem data communications subsystems. The names of these definitions start
with either ZCOM or ZCMK. See also definition or definition files. Compare SPI
standard definitions or EMS standard definitions.
Data Link Layer. Layer 2 in the OSI Reference Model. This layer packages data for
transmission across the network and ensures that the data arrives at the next layer
without any errors.
Data list. In DSM programmatic interfaces, a group of tokens used to separate response
records within an SPI message for a response, or to enclose a single response record, if
the program so requests. A data list consists of a list token that denotes a data list
(different from the token that starts an error list or a generic list), followed by a
response record and an end-list token. See also response record.
Data token. One of the four types of Session Layer tokens that are associated with
functional units. See Token and Functional unit.
Data-portion token. In DSM programmatic interfaces, a token in the body of an SPI
message, rather than in the header. Data-portion tokens are placed in the buffer by
using an SSPUT or SSPUTTKN operation. Some data-portion tokens can occur
multiple times in the buffer, and most can be enclosed in lists. Programs can set the
current position to the tokens and can retrieve their values by using the NEXTCODE
and NEXTTOKEN operations. Compare header token.
Data-transfer phase. The phase of an OSI connection in which data is transferred. This
phase begins when connection establishment is completed. Compare
connection-establishment phase or connection-release phase.
Definition. One of the declarations provided by Tandem for use in applications that call
APS or SPI procedures. These definitions are provided in definition files. See also
definition files.
Definition files. (1) A set of files containing declarations for use in applications that call
SPI procedures. SPI has a standard definition file for Data Definition Language (DDL)
and one for each of the programming languages supporting SPI; the latter files are
derived from the DDL definition file. Likewise, each subsystem that has a token-
oriented programmatic interface has one definition file for DDL and one for each
programming language. Some subsystems—for instance, data communications
subsystems—have additional, shared definition files. See also SPI standard
definitions, data communications standard definitions, or EMS standard definitions.
(2) A set of files containing declarations for use in applications that call some set of
product-specific procedures, such as the APS procedures. See also APS procedures.
Dialog unit. In the Session Layer, the work carried out between two major
synchronization points chosen by the application. See also major synchronization.
Distributed Systems Management. See DSM.