Telecommunications terms starting with D

656 terms

D Dust
D channel In ISDN, the 16-kb/s segment of a 144-kb/s, full-duplex subscriber service channel that is subdivided into 2B+D channels, i.e.
D layer See D region, ionosphere.
D Region In solar-terrestrial terms, a daytime layer of the earth's ionosphere approximately 50 to 90 km in altitude.
D-4 A framing standard for traditional time-division multiplexing, which standard describes user channels multiplexed onto a trunk that has been segmented…
D-A Digital-to-Analog
D-Star(D*) Synonym specific detectivity.
D-type patch bay A patch bay designed for patching and monitoring of unbalanced data circuits at rates up to 1 Mb/s.
D1 See channel bank.
D2 Projective (interceptor) in the Hyper-Velocity Gun program.
D3 See channel bank.
D4 See channel bank.
DACS Divert and Attitude Control System.
daemon Abbreviation for disk and execution monitor. A procedure that is invoked without being called explicitly whenever an alteration, an addition, or a…
DAMA Demand Assigned Multiple Access.
Damping Resistance which reduces vibration by energy absorption.
Damping ratio The ratio of the actual damping to the critical damping, critical damping being the minimum amount of damping which prevents free oscillatory vibration.
dangling threat Set of properties about the external environment for which there is no corresponding vulnerability and therefore no implied risk. [INFOSEC-99]
dangling vulnerability [A] set of properties about the internal environment for which there is no corresponding threat and, therefore, no implied risk. [INFOSEC-99]
dark current The external current that, under specified biasing conditions, flows in a photoconductive detector when there is no incident radiation.
DAT An acronym for Digital Audio Tape, which some backup systems utilize as a storage medium.
data A representation of facts, concepts, or instructions in a formalized manner suitable for communication, interpretation, or processing by humans or by…
data access arrangement In public switched telephone networks, a single item or group of items at the customer side of the network interface for data transmission purposes…
data aggregation [In security,] the compilation of unclassified individual data systems and data elements resulting in the totality of the information being classified.
data attribute A characteristic of a data element such as length, value, or method of representation.
data authentication A process used to verify data integrity, e.g., verification that data received are identical to data sent, or verification that a program is not infected…
data bank A set of data related to a given subject and organized in such a way that it can be consulted by users. 2.
data base node (DBN) A signaling point that acts as a repository of information and provides query/response services for processing and routing of certain types of network…
data burst Synonym burst transmission.
data bus A bus used to transfer data within or to and from a processing unit or storage device.
data channel Communication link(s) over which the actual data of interest flows. High Bandwidth; authenticated by default; encryption and integrity protection optional.
data circuit connection The interconnection of any combination of links and trunks, on a tandem basis, by means of switching equipment to facilitate information interchange.
data circuit-terminating equipment See DCE.
data collection facility A facility for gathering and organizing data from a group of sources.
data collection processor A communications device, serving as mediation equipment in the telecommunication management network, that provides concentration, protocol conversion, and…
data communication The transfer of information between functional units by means of data transmission according to a protocol.
data communication control procedure A means used to control the orderly communication of information among stations in a data communication network.
data communication network (DCN) A configuration of telecommunication facilities for the purpose of transmitting data, as opposed to analog signals. [After T1.210-1989]
data communications control character See control character.
data communications equipment Deprecated term. See DCE.
data compaction The reduction of the number of data elements, bandwidth, cost, and time for the generation, transmission, and storage of data without loss of information…
data composite A collection of data elements treated as a unit. [T1.238-1994/97] [T1.266-2000]
data compression Increasing the amount of data that can be stored in a given domain, such as space, time, or frequency, or contained in a given message length. 2.
data concentrator A functional unit that permits a common transmission medium to serve more data sources than there are channels currently available within the transmission…
data conferencing repeater A device that enables any one user of a group of users to transmit a message to all other users in that group. Synonym technical control hubbing repeater.
data contamination Synonym data corruption.
data corruption An accidental or intentional violation of data integrity. [2382-pt.8]
data country code A 3-digit numerical country identifier that is part of the 14-digit network terminal numbering plan.
data definition The process of creating a complete description of the structure of a database by identifying and describing data elements and their relationships that…
Data definition language (DDL) SQL statements that can be used either interactively or within programming language source code to define databases and their components.
data description language (DDL) Synonym data definition language.
data dictionary A catalog of all data held in a database, or a list of items giving data names and structures. Also referred to as DD/D for data dictionary/directory.
data directory a directory that contains local applications, local templates, country language services (CLUs) files, DESKTOP.
Data Element A combination of characters or bytes referring to one separate piece of information, such as name, address, or age.
Data Encryption Standard (DES) A U.S. Government-approved, symmetric cipher, encryption algorithm used by business and civilian government agencies.
data flow control Synonym information flow control.
data forwarder A device that (a) receives data from one data link and retransmits data representing the same information, using proper format and link protocols, to…
data frame A presentation unit of the data channel; a defined group of consecutive data bits.
Data Integrity The state that exists when computerized data is the same as that in the source documents and has not been exposed to accidental or malicious alteration or…
data item A named component of a data element; usually the smallest component. 2. A subunit of descriptive information or value classified under a data element.
data key A cryptographic key used for authentication or for encryption and decryption. [After X9.17]
data link The means of connecting one location to another for the purpose of transmitting and receiving data. [JP 1-02] 2.
data link connection identifier (DLCI) In frame-relay transmission systems, 13-bit field that defines the destination address of a packet. The address is local on a link-by-link basis.
data link escape character (DLE) A transmission control character that changes the meaning of a limited number of contiguously following characters or coded representations.
Data Link Layer See Open Systems Interconnection--Reference Model.
data logging The dating, time-labeling, and recording of data.
data management The control of data handling operations--such as acquisition, analysis, translation, coding, storage, retrieval, and distribution of data--but not…
data management system See database management system.
data medium The material in or on which one or more characteristics of the material may be used to represent information statically or dynamically.
Data Mining Data mining generally refers to techniques for extracting summaries and reports from an organizations databases and data sets.
data mode In a communications network, the state of data circuit-terminating equipment (DCE) when connected to a communications channel and ready to transmit data…
Data Network Control Center (DNCC) or Equivalent Is the name used to describe the center which administers and maintains Data Networks (e.g., X.75 Gateways).
data network identification code (DNIC) In the ITU-T International X.121 format, the first four digits of the international data number, the three digits that may represent the data country…
data numbering plan area (DNPA) In the U.S. implementation of a ITU-T X.25 network, the first three digits of a network terminal number (NTN).
data origin authentication Corroborating the source of data is as claimed. [INFOSEC-99]
data phase The phase of a data call during which data may be transferred between data terminal equipments (DTEs) that are interconnected via the network.
data processing Handling and processing of information necessary to record the transactions of an organization.
data processing equipment Office equipment such as that using punched cards, punched tape, magnetic or other comparable storage media as an operating vehicle for recording and…
data protection The implementation of administrative, technical, or physical measures to guard against the unauthorized access to data. [2382-pt.8]
data rate See data signaling rate.
data reconstitution A method of data restoration by assembling data from components available from alternative sources. [After 2382-pt.8]
data reconstruction A method of data restoration by analyzing original sources. [2382-pt.8]
data register See register.
data restoration The act of regenerating data that have been lost or contaminated. Note: Methods include copying data from archive, data reconstitution from alternative…
data scrambler A device used in digital transmission systems to convert digital signals into a pseudorandom sequence that is free from long strings of simple patterns…
data security [The] protection of data from unauthorized (accidental or intentional) modification, destruction, or disclosure. [INFOSEC-99]
data separation The application of encryption as a means of access control. [After X9.69]
data service unit (DSU) A device used for interfacing data terminal equipment (DTE) to the public telephone network. 2.
data set A named or defined collection of data. See also Production Data Set and Privilege Data Set.
data signaling rate (DSR) The aggregate rate at which data pass a point in the transmission path of a data transmission system.
data signaling rate transparency See transparency.
data sink See sink.
data source Any repository of data from which documents can be retrieved, such as the Web, relational and nonrelational databases, and content management systems.
data station Data terminal equipment (DTE), data circuit-terminating equipment (DCE), and any intermediate equipment connected at one location.
data stream A sequence of digitally encoded signals used to represent information in transmission.
data subscriber terminal equipment In the DDN, a general purpose terminal device that consists of (a) all the equipment necessary to provide interface functions, perform code conversion…
data switching exchange (DSE) The equipment installed at a single location to perform switching functions such as circuit switching, message switching, and packet switching.
data template A specified logical structure for a collection of data objects, including allowable ranges for their values and other data consistency specifications. [T1.
data terminal equipment See DTE.
data transfer device [A] fill device designed to securely store, transport, and transfer electronically both COMSEC and TRANSEC key, designed to be backward compatible with…