SXSAbbreviation for step-by-step switching system.
syllabary[A] list of individual letters, combination of letters, or syllables, with their equivalent code groups, used for spelling out words or proper names not…
syllableA character string or a bit string in a word.
symbolic languageA computer programming language used to express addresses and instructions with symbols convenient to humans rather than to machines.
symbolic logicThe discipline in which valid arguments and operations are dealt with using an artificial language designed to avoid the ambiguities and logical…
symmetric authentication methodMethod for demonstrating knowledge of a secret, in which both entities share a common authentication information [10181-2].
symmetric cryptographyCryptography in which the same key is used for encryption and decryption. [2382-pt.8]
symmetrical channelA channel in which the send and receive circuits have the same data signaling rate.
symmetrical pairA balanced transmission line, in a multipair cable, having equal conductor resistances per unit length, equal impedances from each conductor to earth, and…
symmetryThe attribute describing the relationship of information flow between two (or more) access points or reference points involved in a communication.
synchronismThe state of being synchronous. 2. For repetitive events with the same, multiple, or submultiple repetition rates, a relationship among the events such…
SynchronizationFor data streams, the process whereby a received set of data is placed in one to one correspondence with the data assumed to have been transmitted.
synchronization bitA bit used to achieve or maintain synchronism. Note: The term "synchronization bit" is usually applied to digital data streams, whereas the term…
synchronization codeIn digital systems, a sequence of bits introduced into a transmitted signal to achieve or maintain synchronism.
synchronization pulseA pulse used to achieve or maintain synchronism. Note: The term "synchronization pulse" is usually applied to analog signals, whereas the term…
synchronizingAchieving and maintaining synchronism. 2. In facsimile, achieving and maintaining predetermined speed relations between the scanning spot and the…
synchronizing pilotIn FDM, a reference frequency used for achieving and maintaining syntonization of the oscillators of a carrier system or for comparing the frequencies or…
synchronizing signalIn facsimile systems, the signal that maintains predetermined speed relations between the scanning spot and recording spot within each facsimile scanning…
synchronousProgramming in which the orderly sequence of events can be determined; that is, when things happen one after the other, not at the same time.
synchronous crypto-operation[A] method of on-line crypto-operation in which crypto-equipment and associated terminals have timing systems to keep them in step. [INFOSEC-99]
synchronous data networkA data network in which synchronism is achieved and maintained between data circuit-terminating equipment (DCE) and the data switching exchange (DSE), and…
synchronous idle character (SYN)A transmission control character used in synchronous transmission systems to provide a signal from which synchronism or synchronous correction may be…
synchronous networkA network in which clocks are controlled to run, ideally, at identical rates, or at the same mean rate with a fixed relative phase displacement, within a…
synchronous orbitAny orbit in which an orbiting object has a period equal to the average rotational period of the body being orbited, and in the same direction of rotation…
synchronous payloadsPayloads derivable from a network transmission signal by removing integral numbers of bits in every frame, i.e.
synchronous systemA system in which events, such as signals, occur in synchronism. Note 1: An example of a synchronous system is one in which a transmitter and receiver…
synchronous tandem encodingA transcoding of the form ADPCM-PCM-ADPCM (adaptive differential pulse code modulation-pulse code modulation-adaptive differential pulse code modulation)…
synchronous TDMA multiplexing scheme in which timing is obtained from a clock that controls both the multiplexer and the channel source.
Synchronous Test Line (103)The term "Synchronous Test Line" denotes an arrangement in an end office which performs marginal operational tests of supervisory and ring-tripping…
synchronous transfer modeIn a Broadband Integrated Services Digital Network (B-ISDN), a proposed transport level technique in which time-division multiplexing and switching is to…
synchronous transmissionDigital transmission in which the time interval between any two similar significant instants in the overall bit stream is always an integral number of…
synchronous transport signal level 1 (STS-1)The basic logical building block signal of synchronous optical networks (SONET). The STS-1 signal has a bit rate of 51.840 Mb/s. [T1.X1] [After T1.
syntaxFrom Greek, "with-arrangement". How things (particularly symbols) are put together with each other.
syntonizationThe process of setting the frequency of one oscillator equal to that of another.
SystemPhysically connected generation, transmission, and distribution facilities operated as an integrated unit under one central management, or operating…
system administrationIn computer technology, a set of functions that provides support services, ensures reliable operations, promotes efficient use of the system, and ensures…
system administratorThe person responsible for configuring and administering the enterprise's computers, networks, and software systems.
system analysisA systematic investigation of a real or planned system to determine the functions of the system and how they relate to each other and to any other system.
system blocking signalA control message generated within a telecommunications system to indicate temporary unavailability of system resources required to complete a requested…
system definitionThe identification of the boundaries of a system to establish a firm basis for any interconnection with other systems [CESG].
system documentationThe collection of documents that describes the requirements, capabilities, limitations, design, operation, and maintenance of a system, such as a…
system failure transferIn the event of a catastrophic failure, the ability to transfer central office trunks or interoffice trunking to predetermined stations to allow incoming…
system follow-upThe study of the effects of a system after it has reached a stabilized state of operational use.
system generation (SYSGEN)The process of selecting optional parts of an operating system and of creating a particular operating system tailored to the requirements of a data…
system high mode1. [An] information system (IS) security mode of operation wherein each user, with direct or indirect access to the information system (IS), its…
system indicator[A] symbol or group of symbols in an off-line encrypted message identifying the specific cryptosystem or key used in the encryption. [INFOSEC-99]
system integrationThe progressive linking and testing of system components to merge their functional and technical characteristics into a comprehensive, interoperable…
System IntegrityThe quality that a system has when it performs its intended function in an unimpaired manner, free from unauthorized manipulation of the system, whether…
system interconnection security policy (SISP)A bilateral memorandum of agreement between two System Managers on the security aspects of an interconnection between their two systems [CESG].
system internal interface (SII)The interface between application platform service components within that platform; it may be standardized or non-standard [POSIX.0].
system keyA key used to provide privacy to an encrypted object as it transits a communications network. [After X9.69]
system life cycleThe course of developmental changes through which a system passes from its conception to the termination of its use and subsequent salvage.
system loadingIn a frequency-division multiplexed (FDM) transmission system, the absolute power level of the composite signal transmitted in one direction.
system managementNetwork management functions extended to include subscriber elements or user end instruments. 2. In computer systems, synonym system administration.
System ManagerA general term of reference to those organizations directed by individual managers, exercising authority over the planning, direction, and control, of…
system operational thresholdFor a supported performance parameter of a system, the value that establishes the minimum operational service performance level for the parameter.
system profile[In INFOSEC, the] detailed security description of the physical structure, equipment component, location, relationships, and general operating environment…
system reliabilityThe probability that a system, including all hardware, firmware, and software, will satisfactorily perform the task for which it was designed or intended…
system robustnessThe measure or extent of the ability of a system, such as a computer, communications, data processing, or weapons system, to continue to function despite…
system security[In INFOSEC, the] degree of security as determined by evaluation of the totality of all system elements and INFOSEC countermeasures. [INFOSEC-99]
system security engineeringThe effort to achieve and maintain optimal security and survivability of a system throughout its life cycle. [INFOSEC-99]
system security evaluationRisk assessment of a system, considering its vulnerabilities and perceived security threat. [INFOSEC-99]
system security officerThe person responsible to the System Manager for writing, enforcing and reviewing Security Operating Procedures (SyOPs) [CESG].
system security policy (SSP)1. The set of laws, rules and practices that regulate how sensitive information and other resources are managed, protected and distributed within a…
system servicesFirmware and software that provide an aggregation of network element functions into a higher level function; provide an interface to the data contained in…
system services APIAn interface providing access to services associated with the application's internal resources [POSIX.0].
system signaling and supervisionIn transmission systems, any scheme used to provide such functions as system control, addressing, routing, error detection and correction, level control…
System SoftwareThe special software within the cryptographic boundary (e.g., operating system, compilers or utility programs) designed for a specific computer system or…
system standardIn the military community, the system-specific characteristics, not dictated by the individual components' electrical performance characteristics, but…
system supervisionIn telephone systems, the use of signals and techniques to perform system management functions, such as system control, addressing, routing, error…
system supportThe continued provision of services and material necessary for the use and improvement of a system during its life cycle.
system test timeThe part of operating time during which a functional unit is tested for proper operation.
systems controlIn a communications system, the control and implementation of a set of functions that (a) prevent or eliminate degradation of any part of the system, (b)…
systems designA process of defining the hardware and software architecture, components, modules, interfaces, and data for a system to satisfy specified requirements. 2.
Systems EngineeringAn interdisciplinary approach to evolve and verify an integrated and life cycle balanced set of system product and process solutions. 287
T reference pointIn Integrated Services Digital Networks (ISDN), the conceptual point dividing NT2 and NT1 functional groupings in a particular ISDN arrangement.
T-carrierThe generic designator for any of several digitally multiplexed telecommunications carrier systems.
T-couplerA passive optical coupler having three ports (three fibers). Note 1: Two isolated inputs may be combined into one output; or one input, into two isolated…
T-interfaceFor basic rate access in an Integrated Services Digital Network (ISDN) environment, a user-to-network interface reference point that (a) is characterized…