OSI/TS Management Programming Manual

Glossary
056786 Tandem Computers Incorporated Glossary-5
Connectionless mode. A type of communication in which all the packets of data (over
the duration of the communications session) are treated independently and in which
functions such as error recovery and flow control are not practical. Contrast
connection mode.
Consumer distributor. An EMS distributor process that returns selected event messages
to management applications upon request. See also distributor.
Context. See application context.
Context token. In DSM programmatic interfaces, a token in an SPI response message
that indicates (by its presence or absence) whether or not the response is continued in
the following message. If this token is present, the response is continued. To obtain
the next message, the application program reissues the original command with one
modification: the context token is included in the new command message. When the
subsystem sends a response message that does not contain a context token, the series
of response messages is complete.
Control and inquiry. In DSM, those aspects of object management that affect the state or
configuration of an object, such as inquiries about the object and commands pertaining
to the environment (for example, commands that set default values for the session).
Compare event management.
COUP (Configuration Utility Program). An interactive program that allows system
managers to make online changes to the configuration of devices and controllers.
COUP is part of the Dynamic System Configuration (DSC) facility, which is not used
to configure Tandem OSI subsystem objects, but which can be used to configure the
underlying X25AM and TLAM objects.
Critical event. A DSM event that is considered to be crucial to the operation of the
system or network. Each subsystem determines which of its events are critical,
designating them as such by setting the value of the emphasis token to TRUE.
Compare noncritical event.
CRTPID. Creation timestamp form of process identifier, used in C-series and earlier
systems. D-series systems use process handles to uniquely identify processes. See also
process handle.
CSMA/CD (carrier sense multiple access with collision detection). An IEEE 802.3 standard for
the Physical Layer of the OSI Reference Model that defines CSMA/CD data
transmission over baseband or broadband LAN networks.
D-series system. A system running any Dxx version of the Guardian 90 operating
system, such as D00 or D10.
Data chaining. An addressing technique used in APS programming whereby the data
associated with a data-element header resides elsewhere in memory rather than in the
user data buffer and is pointed to by a field within the data-element header. This
technique, which is used only with the APS_DATA_REQ_ and
APS_TYPEDDATA_REQ_ procedures, enables the user to avoid moving large blocks
of data within memory.