OSI/MHS Orientation Guide

Glossary
OSI/MHS Orientation Guide—424829-001
Glossary-16
In DSM, an entity subject to independent reference and control by a subsystem: for
example, the disk volume $DATA or the data communications line $X2502. An object
typically has a name and a type known to the controlling subsystem.
In GPI, a collection of elements (called “attributes”) used for constructing messages.
See also root object, subobject, and superobject.
object identifier. In ASN.1, a set of values identifying an object in an ASN.1 abstract syntax
notation defined by the CCITT.
In the GPI, a unique identifier of a particular object generated by the GPI service when
the client program creates a new object, copies an object, or reserves an object. The
client program passes the object identifier to any GPI procedure operating on the object.
A GPI object identifier is not related to an ASN.1 object identifier.
object management. A means to operate on messages and their elements as objects.
object-name template. In DSM, a name that stands for more than one object. Such a name
includes one or more wild-card characters, such as * and ?. See also wild-card
character.
object tree. The internal form of an X.400 communication maintained by the GPI.
object type. In DSM, the category of objects to which a specific object belongs: for example,
a specific disk file might have the object type FILE, and a specific terminal might have
the object type SU (subdevice). A subsystem identifies a set of object types for the
objects it manages. The SCF interfaces to Compaq data communications subsystems
use standard keywords to identify the types. The corresponding programmatic
interfaces have object-type numbers (represented by symbolic names such as ZCOM-
OBJ-SU) suitable for passing to the SPI SSINIT procedure. In the GPI, a category of
objects having a common purpose and structure is called a “class.”
octet. A sequence of eight bits. Also called a “byte” or “character.”
octet string. A string comprising octets.
open system. A computer system based on standard technologies: for example, one that
adheres to the OSI standards.
originator. The person or application that prepares and submits messages for delivery
through an X.400 message handling system.
O/R (originator/recipient) address. A list of attributes that describes a user and locates that
user in relation to the physical or organizational structure of the MHS or the underlying
network. An O/R address, which is part of the O/R name, provides routing information
for an X.400 message handling system.
O/R (originator/recipient) name. A list of attributes that identifies a user as an originator or
potential recipient of a message or probe. An O/R name contains an O/R address.
OSI (Open Systems Interconnection). A set of standards used for the interconnection of
heterogeneous computer systems, thus providing universal connectivity.
OSI manager process. A process in the OSI/AS subsystem that performs subsystem
management functions. The OSI manager process is the focal point for all OSI