data and control characters. (2) A method of controlling
the number of data bits sent on a telecommunication
line in a given time.
collision. An unwanted condition that results from
concurrent transmissions on a channel. (T)
collision detection. In carrier sense multiple access
with collision detection (CSMA/CD), a signal indicating
that two or more stations are transmitting
simultaneously.
Committed information rate. The maximum amount
of data in bits that the network agrees to deliver.
community. In the Simple Network Management
Protocol (SNMP), an administrative relationship between
entities.
community name. In the Simple Network
Management Protocol (SNMP), a string of octets
identifying a community.
compression. (1) The process of eliminating gaps,
empty fields, redundancies, and unnecessary data to
shorten the length of records or blocks. (2) Any
encoding to reduce the number of bits used to represent
a given message or record.
configuration. (1) The manner in which the hardware
and software of an information processing system are
organized and interconnected. (T) (2) The devices
and programs that make up a system, subsystem, or
network.
configuration database (CDB). A database that
stores the configuration parameters of one or several
devices. It is prepared and updated using the
configuration program.
configuration file. A file that specifies the
characteristics of a system device or network.
configuration parameter. A variable in a configuration
definition, the values of which can characterize the
relationship of a product to other products in the same
network or can define characteristics of the product
itself.
configuration report server (CRS). In the IBM
Token-Ring Network Bridge Program, the server that
accepts commands from the LAN Network Manager
(LNM) to get station information, set station parameters,
and remove stations on its ring. This server also collects
and forwards configuration reports generated by stations
on its ring. The configuration reports include the new
active monitor reports and the nearest active upstream
neighbor (NAUN) reports.
congestion. See
network congestion
.
connection. In data communication, an association
established between functional units for conveying
information. (I) (A)
control point (CP). (1) A component of an APPN or
LEN node that manages the resources of that node. In
an APPN node, the CP is capable of engaging in
CP-CP sessions with other APPN nodes. In an APPN
network node, the CP also provides services to adjacent
end nodes in the APPN network. (2) A component of a
node that manages resources of that node and
optionally provides services to other nodes in the
network. Examples are a system services control point
(SSCP) in a type 5 subarea node, a network node
control point (NNCP) in an APPN network node, and an
end node control point (ENCP) in an APPN or LEN end
node. An SSCP and an NNCP can provide services to
other nodes.
control point management services (CPMS). A
component of a control point, consisting of management
services function sets, that provides facilities to assist in
performing problem management, performance and
accounting management, change management, and
configuration management. Capabilities provided by the
CPMS include sending requests to physical unit
management services (PUMS) to test system resources,
collecting statistical information (for example, error and
performance data) from PUMS about the system
resources, and analyzing and presenting test results
and statistical information collected about the system
resources. Analysis and presentation responsibilities for
problem determination and performance monitoring can
be distributed among multiple CPMSs.
control point management services unit (CP-MSU).
The message unit that contains management services
data and flows between management services function
sets. This message unit is in general data stream (GDS)
format. See also
management services unit (MSU)
and
network management vector transport (NMVT)
.
D
D-bit. Delivery-confirmation bit. In X.25
communications, the bit in a data packet or call-request
packet that is set to 1 if end-to-end acknowledgment
(delivery confirmation) is required from the recipient.
daemon. A program that runs unattended to perform a
standard service. Some daemons are triggered
automatically to perform their task; others operate
periodically.
data carrier detect (DCD). Synonym for
received line
signal detector (RLSD)
.
data circuit. (1) A pair of associated transmit and
receive channels that provide a means of two-way data
communication. (I) (2) In SNA, synonym for
link
connection
. (3) See also
physical circuit
and
virtual
circuit
.
Glossary 695
