In the
Distributed Computing Environment (DCE) X/OPEN Directory Service (XDS), an
application program interface (API) that DCE uses to access its directory
service components. XDS provides facilities for adding, deleting, and
looking up names and their
attributes.
X/Open Object Management (XOM)
An
interface for creating, deleting, and accessing objects containing
information. It is an object-oriented architecture. Each object
belongs to a particular class, and classes can be derived from other classes,
inheriting the characteristics of the original class. The
representation of the object is transparent to the programmer; the object
can be manipulated only through the XOM
interface.
X/OPEN transport interface (XTI)
A
protocol-independent transport-layer interface for applications that consists
of a series of C language functions based on TLI, which, in turn, was based on
the transport service definition for the OSI model.
XTI
See X/OPEN transport
interface (XTI).
X.121
A CCITT
Recommendation that provides a method for the international numbering of
X.25 packet-switching data networks.
X.21
In data
communications, a specification of the CCITT that defines the connection of
data terminal equipment to an X.21 (public data)
network.
X.21bis
In data
communications, an interim specification of the CCITT that defines the
connection of data terminal equipment (DTE) to an X.21 (public data)
network using V-series interchange circuits such as those defined by CCITT
V.24 and CCITT V.35.
X.25
A CCITT
Recommendation that defines the physical level (physical layer), link level
(data link layer), and packet level (network layer) of the OSI reference
model. An X.25 network is an interface between data terminal
equipment (DTE) and data circuit-terminating equipment (DCE) operating in the
packet mode, and connected to public data networks by dedicated
circuits. X.25 networks use the connection-mode network
service.
X.25 protocol
The
connection-mode network service that the CCITT specifies in Recommendation
X.25.
X.25 protocol ID
In OSI, a
technique that OSI Communications Subsystem uses to pass an NSAP address when
using the 1980 level of the X.25 protocol.
X.25 subnetwork
In OSI, a
subnetwork that conforms to the X.25 protocols.
X.400
A CCITT
Recommendation for international electronic mail
(messages).
X.500
A CCITT
Recommendation for OSI directory service.
X.75
In data
communications, a specification that defines ways of connecting two
X.25 networks.