NBT Manual

Glossary
NBT Manual—424773-001
Glossary-4
critical event
critical event. A DSM event that is considered to be crucial to the operation of the system or
network. Each subsystem determines which of its events are critical, designating them as
such by setting the value of the emphasis token to TRUE. Compare noncritical event.
CSMA (Carrier Sense Multiple Access). A characteristic of network hardware that operates
by allowing multiple stations to contend for access to a transmission medium by
listening to see if it is idle.
CSMA/CD (Carrier Sense Multiple Access with Collision Detection). A characteristic of
network hardware that uses CSMA access combined with a mechanism that allows the
hardware to detect when two stations simultaneously attempt transmission. Ethernet is
an example of a well-known network based on CSMA/CD technology.
DARPA (Defense Advanced Projects Research Agency). Formerly called ARPA. The
government agency that funded research and experimentation with the ARPANET and
DARPA Internet.
data communications standard definitions. In DSM, the set of declarations provided by
Compaq for use in all management programs that manage or retrieve event messages
from Compaq 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 list. In DSM programmatic interfaces, a group of tokens used to separate response
records within an SPI message for a response, or used 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
.
DDN (Defense Data Network). Used to loosely refer to the MILNET, ARPANET, and the
TCP/IP protocols they use. More literally, it is the MILNET and associated parts of the
Internet that connect military installations.
definition. One of the declarations provided by Compaq for use in applications that call APS
or SPI procedures. These definitions are provided in definition files. See also definition
files.
definition files. A set of files containing declarations for use in applications that call SPI
procedures. SPI has a standard definition file for the 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.