The interface point in an ISDN environment between the line termination and the exchange termination.
- Browse Related Terms: attachment unit interface (AUI), medium interface connector (MIC), medium interface point (MIP), message register leads, originating connection, R interface, S interface, S reference point, T-interface, terminal adapter, Trunk Gateway, U reference point, V reference point, wireline access mode
Sets of telecommunications protocols and interfaces defined by CCITT (now ITU-T) Recommendations. Note: Some of the more common V.-series Recommendations are:
- V.21: A CCITT Recommendation for modem communications over standard commercially available lines at 300 b/s. This protocol is generally not used in the United States.
- V.22bis: A CCITT Recommendation for modem communications over standard commercially available voice-grade channels at 2,400 b/s and below.
- V.32: A CCITT Recommendation for modem communications over standard commercially available voice-grade channels at 9.6 kb/s and below.
- V.32bis: A CCITT Recommendation for modem communication over standard commercially available voice-grade channels at 14.4 kb/s and below.
- V.34: An ITU-T Recommendation for modem communication over standard commercially available voice-grade channels at 28.8 kb/s and below.
- V.42: A CCITT Recommendation for error correction on modem communications.
- V.42bis: A CCITT Recommendation for data compression on a modem circuit.
- V.FAST: A new CCITT Recommendation for high-speed modems currently under development.
- Browse Related Terms: access node, Advanced Data Communication Control Procedures (ADCCP), binary synchronous (bi-sync) communication, cell header, communications protocol, encapsulation, Entity, NCI code, network interface device (NID), network termination, protocol abnormality, protocol data unit (PDU), protocol hierarchy, routing table, simplex protocol, synchronous data link control (SDLC), transmission frame, V-series Recommendations, virtual local area network (VLAN), wireless access mode
1. Tests to determine whether an implemented system fulfills its requirements. 2. The checking of data for correctness or for compliance with applicable standards, rules, and conventions. 3. [The] process of applying specialized security test and evaluation procedures, tools, and equipment needed to establish acceptance for joint usage of an information system (IS) by one or more departments or agencies and their contractors. [INFOSEC-99] Note: This action will include, as necessary, final development, evaluation, and testing, preparatory to acceptance by senior security test and evaluation staff specialists. [NIS] 4. In universal personal telecommunications, the process of verifying that a user or terminal is authorized to access UPT services. 5. The checking of a representation of a system or part of a system for conformance with its requirements [CESG]. 6. The process of evaluating a ported application, software, or system to ensure compliance with requirements [POSIX.0].
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A company that sells the services of a value-added network.
- Browse Related Terms: accounting management, asymmetric digital subscriber line (ADSL), Broadband, class of service, complementary network service (CNS), enhanced service providers, message handling system (MHS), National Information Infrastructure (NII), teletex, value-added carrier, visual telephone services
A network using the communication services of other commercial carriers, using hardware and software that permit enhanced telecommunication services to be offered.
- Browse Related Terms: bearer service, Blocked Call, blocking, blocking network, conversational service, messaging service, National xxSecurity or Emergency Preparedness telecommunications, network element (NE), operational service state, Outage, primary protector, retrieval service, service identification, teleaction service, telemetry, telephoto, teleservice, terminal mobility, time code, transport, TTY/TDD, value-added network (VAN)
The date the transfer entry to an account is considered effective; either the day the instruction is received or some future date as stipulated by the originator. [After X9.9]
- Browse Related Terms: block transfer failure, message alignment indicator, message transfer part, optical fiber transfer function, overhead information, pre-arbitrated slot, precise time and time interval (PTTI), presentation context, signal message, SMTP, torn-tape relay, transfer rate, user part, value date
A buffer into which data may be entered at one rate and removed at another rate without changing the data sequence. Note: Most first-in first-out (FIFO) storage devices are variable-length buffers in that the input rate may be variable while the output rate is constant or the output rate may be variable while the input rate is constant. Various clocking and control systems are used to allow control of underflow or overflow conditions.
- Browse Related Terms: coordinated clock, phase transients, reference clock, single-ended synchronization, synchronous system, time tick, timing signal, timing tracking accuracy, variable length buffer
See continuously variable slope delta modulation.
- Browse Related Terms: absorption modulation, amplitude intensity modulation (AIM), amplitude modulation (AM), angle modulation, baseband local area network, carrier, carrier frequency, carrier noise level, class of emission, continuously variable slope delta (CVSD) modulation, envelope, fixed-reference modulation, Frequency Modulation (FM), modulation factor, modulation index, modulation rate, modulation suppression, off-the-air, on-the-air, optical repeater, overmodulation, percentage modulation, phase deviation, phase modulation (PM), plate modulation, precombining, predetection, pulse link repeater (PLR), quadrature modulation, radio telephony, single-sideband (SSB) emission, stereophonic crosstalk, subcarrier, two-tone keying, variable slope delta modulation
- In statistics, in a population of samples, the mean of the squares of the differences between the respective samples and their mean, expressed mathematically as:
where n is the number of samples, xi is the value of sample i, is the mean of the samples, and 2 is the variance. Note: The square root of the variance, , is the standard deviation.
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One of two or more code symbols having the same plain text equivalent. [INFOSEC-99] 2. One of several plain text meanings that are represented by a single code group. [JP1]
- Browse Related Terms: authenticator, code book, code group, code vocabulary, one-part code, operations code, syllabary, two-part code, variant
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A new key formed by a nonsecret process with the original key, such that one or more of the nonparity bits of the new key differ from the corresponding bits of the original key. [After X9.8]
- Browse Related Terms: active key state, asymmetric cryptographic algorithm, base key, blue-screening, end-of-message function, forward secrecy, notarization, off-line authentication certificate, public key, public key validation, static data, subscriber data key, triple data encryption algorithm (TDEA), two-tone telegraph, variant of a key, Vernam cypher, working key
In ac power distribution, a device for sensing deviations of any measured variable, such as voltage, current, or frequency, and capable of initiating a programmed action, such as transfer to other power sources, when programmed limits of voltage, current, frequency, or time are exceeded, or providing an alarm, or both.
- Browse Related Terms: adaptive radio, flat fading, FOT, maximum usable frequency (MUF), meaconing, order of diversity, primary substation, protection interval (PI), Rayleigh distribution, ship's emergency transmitter, standard time and frequency signal (STFS) service, variation monitor