OSI/TS Configuration and Management Manual

OSI/TS Configuration and Management Manual—424831-001
Glossary-1
Glossary
The following glossary defines terms used both in this manual and in the other Compaq
OSI/AS and Compaq OSI/TS manuals. Not all terms listed 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.
Abstract Syntax Notation-1. See ASN.1 (Abstract Syntax Notation-1).
ACSE (Association Control Service Element). An application service element (ASE) in
the Application Layer. It exists within an application entity. ACSE helps other ASEs to
work together by establishing and releasing associations. It is accessible to users of
OSI/AS through the APS procedures.
Action event. An event that requires operator intervention. Each subsystem determines
which events are action events by including a unique EMS token in the event message.
Action events are reported as pairs of event messages: an action-attention message to
report the problem and an action-completion message to report the problem resolution.
Activity. In the Session Layer, a logical unit into which the work of an application can be
divided. Only one activity can be in use on a connection at any time, but there may be
several consecutive activities during the connection. An activity can also span more
than one connection: it can be interrupted, then resumed on the same or on a subsequent
connection. An activity can contain one or more dialog units.
Address sharing. The use of multiple addresses on the same physical connection. For
OSI/TS, this type of address sharing can be implemented at and below the Transport
Layer.
AE title. See Application entity title.
.
APDU (application protocol data unit). See PDU (protocol data unit).
.
API (application programmatic interface). A mechanism by which an application
program interfaces with another piece of software. For OSI/AS, the API consists of the
APS procedure calls, the MFM procedure calls, and the data definitions provided in the
ZAPSDDL, ZAPSTAL, and ZAPSC files.
Application context. For a given Application Layer protocol, the specification of the
protocol elements that are available, together with a definition of the types of
information that can be exchanged and described using an abstract syntax (such as
ASN.1), and the agreed meaning of each type of information.
Application context name. The name identifying the application context to be used on an
ACSE connection.