Index - A B C D E F G H I J K L M N O P Q R S T U V W X Y Z A-Z
IEC - 1.) In telecommunications, see "Interexchange Carrier." 2.) In electrical power safety, the International Electrotechnical Commission, promulgators of power safety standards for the world.
IMS/VS (INFORMATION MANAGEMENT SYSTEM/VIRTUAL SYSTEM) - A common IBM large computer operating arrangement, usually using the MVS ( Multiple Virtual System ) operating system oriented toward batch data processing and data communications-based transaction applications.
INFRARED - That portion of the electromagnetic spectrum located at frequencies just below visible light; in fact, the lasers used for so-called " long-wavelength " fiber optics communications at 1300 nanometers are really in the " near-infrared " region, producing an extremely deep ruby red color of such purity and strength as to damage human eye retinae.
INITIALIZE - Setting all counters, switches, addresses or contents of storage to zero at the beginning of, or at prescribed points in the operation of a computer routine or a communications transfer; a major function of " rebooting " a computer, giving everything a " reset ." Also: Initialize ; re-initialize .
INPUT/OUTPUT (I/O) CHANNEL/PORT - 1.) In computers, the hardware function, usually a bus of parallel wires, hence "channel," that transports data in parallel form between the CPU and peripherals like storage, printers or communications; 2.) In communications, usually a serial data port to a computer, then often with controls per RS- 232.
INTELLIGENT TERMINAL - A terminal containing a programmable processor capable of some degree of local processing; the range of functions and degree of capability is not standardized and subject to wide discussion of what constitutes "intelligence."
INTERACTIVE - Involving a duplex, "conversational" exchange between a user and a computer.
INTERCEPT - 1.) In telephony, redirecting a telephone call improper or invalid telephone number to an operator or a recording; 2.) In espionage, receiving telecommunications by wire or radio intended for another party; especially surreptitiously.
INTERCONNECT - 1.) Any of a variety of hardware arrangements that permit the connection of customer's telecommunications equipment to a communications common carrier network. 2.) A portal or communications path or gateway between two common carrier networks. 3.) Industry jargon for non-telcos that provide telephone equipment for customer premises; often called " Interconnect Companies ."
INTER-EXCHANGE MILEAGE (IXC) - The airline mileage between two cities. - Synonym: Long Haul Mileage.
INTEREXCHANGE CARRIER (IEC) - A company providing telecommunications facilities and services principally between the local exchange area LECs, typically identifiable as between two cities or metropolitan areas; particularly interstate and internationally.
INTEREXCHANGE PLANT - The facilities between one switching center and another switching center; sometimes including line-to-line, no-user switching centers called "tandem exchanges ."
INTERFACE - The junction or point of interconnection between two systems or equipment having different characteristics; has both hardware and software implications.
INTERFERENCE - Any unwanted noise, crosstalk or spurious signals on a communications circuit that acts to reduce the intelligibility of the desired information signal or speech.
INTERLEAVING (INTERLEAVE) - 1.) Alternate or sequential transmission of signals from two or more sources in time division multiplexing of a single path; in data communications the interleaving may be character or bit interleaved, with optimum applications for each; 2.) In conjunction with error-correcting codes, a technique to minimize effects of error bursts on message throughput by interleaving groups of characters or blocks that approximate the burst length, so errors tend to affect only one multiplexed channel during an event.
INTER-MACHINE TRUNK (IMT) - A circuit connected between two automatic switching machines; sometimes called a "tandem trunk".
INTERMEDIATE DISTRIBUTING FRAME (IDF) - Descriptive of a wiring termination and rearrangement point located between two main distributing frames (MDF) or between and MDF and an end point in a building.
INTERNATIONAL RECORD CARRIER (IRC) - Carriers providing international telecommunications services, including voice, telex, and data communications. For example, MCI purchased the IRC known as Western Union International and operates it today as MCI International.
INTERNATIONAL STANDARDS ORGANIZATION (ISO) - A world standards body that generally sets standards for any fabricated or manufactured; thus ISO standards apply to physical aspects of the " 25-pin connector " of CCITT V.24/28 data interfaces ( RS-232 ), definitions of the several layers of data networks for which different hardware units may be required, and such diverse things as the exposure speeds of photographic film and definitions of units of measurement. ISO is an Anglicized form of the proper French name of l'Organisme pour l'Standardization Internationale, resident in Geneva, Switzerland. INTERNATIONAL TELECOMMUNICATIONS UNION (ITU) - Anglicization of the proper French name of the Union Internationale des Telecommunications (UIT), resident in Geneva, Switzerland. ITU is the treaty-established world center for agreements on telecommunications technical and operating standards and is a constituent body of the United Nations, engaging also in international development and education concerning telecommunications.
INTERNATIONAL TELEGRAPH ALPHABET #1 (ITA 1) - World- standard CCITT version of the manual telegrapher's code. Colloquial name: International Morse Code.
INTERNATIONAL TELEGRAPH ALPHABET #2 (ITA 2) - World- standard CCITT version of the 5-unit (also called 7.5 unit) teleprinter code used for Telex, international telegrams and most general telegraphy by wirelines; Colloquial name: Baudot code.
INTERNATIONAL TELEGRAPH ALPHABET #3 (ITA 3) - World- standard CCITT version of a 6-unit extended set of ITA 2 to include characters needed for automatic typesetting directly from telegraph circuits. Colloquial names: Teletypesetter code, press code, extended Baudot code, and others.
INTERNATIONAL TELEGRAPH ALPHABET #4 (ITA 4) - World- standard CCITT version of a 7-unit code in which only the combinations using 4 marking bits are valid; receiving any character with more or less than 4 marking bits is its error checking feature. Colloquial names: 7-unit ARQ Code, Moore ARQ Code, Moore Code, RCA Code, and others.
INTERNATIONAL TELEGRAPH ALPHABET #5 (ITA 5) - World- standard CCITT version of a 7-unit teleprinter code with an 8th parity bit also used for asynchronous data terminals such as minicomputers or PCs. Colloquial name: ASCII code.
INTER-OFFICE TRUNK (IOT) - A direct trunk between local exchange offices.
INTERRUPT - Data processing term for a processing stoppage made in such a way as to be resumable. Compare to a " halt ," typically meaning a stoppage that requires initializing the machine to restart processing.
INTERSTATE - A connection or transaction made across the boundaries of two or more states.
INTRASTATE - Any connection or transaction made within the boundaries of a single state.
ISDN (INTEGRATED SERVICES DIGITAL NETWORK) - A global plan under auspices of the CCITT to provide any information service users may desire on a single worldwide public switched network; the ultimate ISDN has as its goal the elimination of need for discrete telephone, telegraph, data, packet and other networks as well as physically dedicated " special services " circuits as now required to provide broadcast, video, high-speed data and numerous functions users want. Where regulatorily permitted, telecommunications entities may also provide information processing services as well as transportation services; while the CCITT is working on defining these, U.S. common carriers are prohibited from doing so ... at least for the present.
IVDT (INTEGRATED VOICE/DATA TERMINAL) - Perhaps the Holy Grail of telecommunications terminal design, as everyone seems to have a perfect plan for what a single electronic device on a desktop ought to be; what functions it should perform when connected by very specific means to the set of resources it needs. But, like the Holy Grail, nobody can say they have really seen one yet. In fact, anyone who does see one may well go berserk, in keeping with the legend of anyone who does look inside the Holy Grail.