NBT Manual

Glossary
NBT Manual—424773-001
Glossary-3
Class D
Class D. A Class D address is a 4-octet multicast group address. The four high-order bits of
the address are always 1110; therefore, the first octet is a number in the range 224
through 239 (%HE0 through %HEF). This means that an Internet can have a total of
268,435,456 multicast groups.
collector. An EMS process that accepts event messages from subsystems and logs them in the
event log. See also Event Management Service (EMS)
. Compare distributor.
command message. A SPI message, containing a command, sent from an application
program to a subsystem. See also SPI message
. Compare response message or event
message.
common definition. In DSM programmatic interfaces, a definition (data declaration) used in
several commands, responses, or event messages in an SPI interface to a subsystem. See
also definition
.
compatibility distributor. An EMS distributor process that filters event messages according
to fixed (rather than user-specified) criteria, obtains text for these messages that is
compatible with the operator console of Guardian operating system versions earlier than
C00, and writes the text to the standard Guardian console-message destinations. See also
distributor
.
conditional token. In DSM event management, a token that is sometimes, but not always,
present in a particular event message.
connection. The path between two protocol modules that provides reliable stream delivery
service. In the Internet, a connection extends from a TCP module on one machine to a
TCP module on another machine.
connectionless service. Characteristic of the packet delivery service offered by most
hardware and by the Internet Protocol (IP). The connectionless service treats each packet
or datagram as a separate entity that contains the source and destination address.
Usually, connectionless services can drop packets or deliver them out of sequence.
consumer distributor. An EMS distributor process that returns selected event messages to
management applications upon request. See also distributor
.
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
.