OSI/AS Management Programming Manual

Glossary
Glossary-2 056785 Tandem Computers Incorporated
Application entity. The part of an application process that interacts with a remote
application process. In an OSI application itself, the application entity is the part that
represents the communication functionality necessary for interoperation.
Application entity title. The name, used with ACSE, that identifies an application entity
to the OSI network. See also application entity. Contrast application name.
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.
Application name. The address by which an application entity is known to the local
OSI/AS subsystem. Application names are defined locally only. Contrast application
entity title.
APS (application, presentation, and session) procedures. A set of procedure calls, included
as part of the OSI/AS subsystem, providing application programs with access to the
services of ACSE (in the Application Layer), the Presentation Layer, and the Session
Layer. The names of the APS procedures all begin with the letters APS. APS
procedures are defined in the EXTDECS files. APS, together with the definitions in the
ZAPSDDL file, is the API to OSI/AS.
ASE (application service element). A set of different functions to be performed—such as
file transfer, mail service, or transaction processing—along with all the elements
necessary to perform that kind of work, to support a particular application.
ASN.1 (Abstract Syntax Notation-1). A standardized method of representing , encoding,
transmitting, and decoding data structures. Based on the CCITT X.409 standard,
ASN.1 is the syntax specified for many application protocols, such as ACSE, FTAM,
and MMS. It is also used by directory services and network management. See also
abstract syntax.
Association. A connection between Application Layer entities. Contrast connection.
Association Control Service Element. See ACSE.
Association procedures. See APS procedures.
Attach. An operation performed by an application using OSI/AS or OSI/TS, in the
Application Layer, Presentation Layer or Session Layer, to indicate that the application
is willing to receive an incoming connect request or association request from a remote
application.
Attribute. In DSM, a characteristic of an entity. For example, two attributes of a
communications line might be its baud rate and its retry count. In a token-oriented
interface based on SPI, an attribute of an object is usually expressed as either a simple
token or as a field within an extensible structured token. See also simple token or
extensible structured token.