SNAX/APC Management Programming Manual

Glossary
111813 Tandem Computers Incorporated Glossary–3
data definition language (DDL). A language and compiler used to define SPI token codes,
token maps, and token types and to generate a DDL definition file and language-
specific definition files; the language-specific files can be included in the source code
for management applications or management interfaces that use SPI.
DDL. See data definition language.
definition files. A set of files containing DDL declarations for use in management
applications or management interfaces that use SPI procedures.
DFC. Data flow control.
DIN. Data transmitted to SNAX/APC.
Dispatcher . The SNAX/APC function that initiates a transaction program when one is
requested by a remote LU.
Distributed Systems Management (DSM). Tandem’s architecture for managing distributed
systems and subsystems. DSM products include the Subsystem Programmatic
Interface, the Event Management Service, and the Subsystem Control Facility.
domain. In SNA, a system services control point (SSCP) and the PUs, LUs, links, and
associated resources that the SSCP has the ability to control by means of activation
requests and deactivation requests.
DOUT. Data transmitted from SNAX/APC.
DSM. See distributed systems management.
EMS. See event management service.
EN. See end node.
end node (EN). A type 2.1 node that provides full SNA end-user services, but no
intermediate routing or session services to any other node; it is configured only as an
endpoint in a network.
EnvoyACP/XF. A Tandem data link control that, combined with a communications-
oriented user application, supports connection with specialized bit-synchronous
devices not supported by higher-level Tandem communications products.
event. A significant change in some condition in the system or network. Events can be
operational errors, notifications of limits exceeded, requests for action needed, and so
on.
Event Management Service (EMS). A part of DSM used to provide event collection, event
logging, and event distribution facilities. It provides for different event descriptions
for interactive and programmatic interfaces, lets an operator or application select
specific event-message data, and allows for flexible distribution of event messages
within a system or network.
Exchange Identifications (XID). A data link control command and response passed
between adjacent link stations that allow the two link stations to exchange
identification and other information that is necessary for further operation over the
data link.