OSI/MHS Orientation Guide

OSI/MHS Orientation Guide—424829-001
Glossary-1
Glossary
The following glossary defines terms used in this manual and in other Compaq
OSI/MHS manuals. Both industry-standard terms and Compaq terms are included. This
list covers Compaq OSI/MHS as a whole; therefore, not all terms given here are used in
this particular manual.
abstract syntax. A representation of the way in which components of information are to be
specified in a communication. It defines a set of primitive elements whose range of
values is fully defined—for example, integers, characters, and Boolean values—and
ways of combining these elements.
access unit. A program that accomplishes the integration, into an X.400 network, of a
specific type of non-X.400 device or system, such as a facsimile network or physical
delivery system. Access units are defined in the 1988 X.400 Recommendations.
adjacent MTA. An MTA that has a direct path to your OSI/MHS subsystem.
ACSE (Association Control Service Element). An application service element (ASE) in the
Application Layer. It exists within an application entity and provides for other ASEs to
work together by establishing and releasing associations.
ADMD (administration management domain). An X.400 domain managed by an
administration, such as a government or a public service. ADMDs can send, receive,
and provide intermediate routing for messages. See domain.
administration management domain. See ADMD.
alternate collector. A process to which subsystems can send event messages, rather than to
the primary collector ($0). An alternate collector maintains its own log files.
APDU (application protocol data unit). See PDU.
API (application programmatic interface, application programming interface, application
program interface). 1) A mechanism by which an application program interacts with
another piece of software, usually software that provides services to the application.
Two examples of APIs are the Compaq OSI/MHS P7 API and the Compaq OSI/MHS
Gateway Programmatic Interface (GPI). 2) The set of functions or procedures that
permits user programs to communicate with the Compaq NonStop Kernel and services.
See Compaq NonStop Kernel.
APPL object. An object type, used in OSI/MHS management interfaces, that defines
information about users of OSI/MHS message stores—that is, about user agents—and
users of gateways. See also UA and GATEWAY object.
Application Layer. Layer 7 of the OSI Reference Model. This layer provides the interface
between user programs (application processes) and the OSI network. Layer 7 includes
the standards for services such as file transfer, electronic mail, and terminal access.
archive queue. A queue to which you can move an object from the input queue during a
finish-transfer-in operation requested of the GPI. Typically, undecodable
communications are placed on the archive queue for future examination using diagnostic
procedures. See also communication.