OSI/FTAM Responder Manual

Glossary
OSI/FTAM Responder Manual—425199-001
Glossary-16
object identifier. A value, distinguishable from all other such values, that is associated
with an ISO information object. A standard representation of an object identifier is a set
of numbers representing a directed path through a standards-based tree hierarchy, often
shown as a sequence of two or more values enclosed in braces ({}). Examples of
objects represented by object identifiers are document type names, constraint sets,
abstract syntaxes, transfer syntaxes, and AE titles.
object state. See state.
object state transition. See state transition.
octet. A byte of data; eight bits.
OctetString. The string type consisting of a string of octets. See octet.
open. An established line of communication between two processes. You can display
the number of opens a process has by issuing the SCF STATUS PROCESS command.
open network. A communications network that is able to communicate between
systems using standardized procedures and functions.
Open Systems Interconnection. See OSI.
operator message. A message, describing a significant event on a Compaq NonStop
system, that is intended to be seen by an operator. An operator message is the
displayed-text form of an EMS event message. See event message.
optional parameter. (1) In a protocol data unit (PDU), a parameter that is sometimes
but not always present. (2) In the Compaq FTAM API, a procedure-call parameter that
can be included in a given procedure call or command, but is not required for use with
the procedure or command. Contrast with conditional parameter and required
parameter.
original-error-info parameter. A parameter in the APS_STATUS_ procedure call that
provides a code identifying the first error detected in Compaq FTAM or an underlying
OSI layer. Using the service ID, which indicates the source of the error, and the value
returned by original-error-info, you can refer to Compaq manuals for further
information about the problem. See also service ID.
OSI (Open Systems Interconnection). A set of standards used for the interconnection
of heterogeneous computer systems designed for universal connectivity.
OSI address. The address of an object on an OSI network. An OSI address consists of
four components: the transport selector (TSEL), session selector (SSEL), presentation
selector (PSEL), and network service access point (NSAP).
OSI/AS (Application Services). The Compaq implementation of the Session Layer, the
Presentation Layer, and part (ACSE) of the Application Layer of the OSI Reference
Model. The OSI/AS subsystem manages the communication of messages between a
local Compaq system and a remote system on a network. This subsystem manages the
lower-layer services provided by Compaq OSI/TS, X25AM, and TLAM.
OSI manager process. A process in the OSI/AS subsystem that performs subsystem
management functions. There is one OSI manager process per OSI/AS subsystem.