Telecom/1996-04-telecom-walnutcreek.iso/glossaries/more.acronyms

Text File | 1993-11-25 | 115KB | 3,122 lines

This telecommunications glossary was found at a naval FTP site.  It
looks similar to glossaries found on most telecommunication-related
BBS systems.

  2780:
          AT BATCH STANDARD USED TO COMMUNICATE WITH IBM MAINFRAMES
          OR COMPATIBLE SYSTEMS.

  3270:
          IBM'S INTERACTIVE COMMUNICATIONS TERMINAL STANDARD USED TO
          COMMUNICATE WITH AN IBM MAINFRAME OR COMPATIBLE SYSTEM.

  3780:
          A BATCH PROTOCOL USED TO COMMUNICATE WITH AN IBM MAINFRAME
          OR COMPATIBLE SYSTEM.

  ABSORPTION:
          CONVERSION OF TRANSMITTED ENERGY, SUCH AS AN ELECTRONIC
          SIGNAL, INTO HEAT OR OTHER FORMS OF ENERGY.

  ACC:
          AUTOMATIC CALLBACK CALLING.  FEATURE THAT ALLOWS THE STATION
          USER, WHEN ENCOUNTERING AN INTERNAL STATION BUSY SIGNAL, TO
          DIAL A 1- OR 2-DIGIT CODE AND HANG UP.  WHEN BOTH PARTIES
          ARE FREE, THE SYSTEM AUTOMATICALLY RINGS AND CONNECTS THE
          PARTIES.  WHILE ACTIVATED, THIS FEATURE DOES NOT PREVENT THE
          CALLING STATION FROM EITHER INITIATING OR RECEIVING CALLS.

  ACCEPTANCE TEST:
          OPERATING AND TESTING OF A NEW SYSTEM TO ENSURE THAT THE
          SYSTEM IS OPERATING SATISFACTORILY BEFORE BEING ACCEPTED
          BY THE PURCHASER.

  ACCESS:
          TO OBTAIN DATA FROM MEMORY, A PERIPHERAL, OR ANOTHER SYSTEM.

  ACCESS ARM:
          THE MECHANICAL DEVICE IN A DISK STORAGE UNIT THAT HOLDS ONE
          OR MORE READ/WRITE HEADS.

  ACCESS CHARGE:
          COST ASSESSED TO COMMUNICATIONS USERS FOR ACCESS TO THE
          INTEREXCHANGE, INTERSTATE MESSAGE TOLL TELEPHONE NETWORK
          TO ORIGINATE AND RECEIVE INTERSTATE TOLL CALLS, AS WELL
          AS ACCESS TO THE CUSTOMER'S LOCAL ACCESS AND TRANSPORT
          AREA (LATA).

  ACCESS CODE:
          THE DIGIT, OR DIGITS, THAT A USER MUST DIAL TO BE
          CONNECTED TO AN OUTGOING TRUNK FACILITY.

  ACCESS CONTROL:
          HARDWARE, SOFTWARE, AND ADMINISTRATIVE TASKS THAT MONITOR
          SYSTEM OPERATION, PERFORM USER IDENTIFICATION, AND RECORD
          SYSTEM ACCESSES AND CHANGES.

  ACCESS LINE:
          CONNECTION FROM THE CUSTOMER TO THE LOCAL TELEPHONE
          COMPANY FOR ACCESS TO THE TELEPHONE NETWORK; ALSO
          REPRESENTS THE CONNECTION BETWEEN THE SERVING TOLL CENTER
          AND THE SERVING OFFICE OF THE INTEREXCHANGE CARRIER USED
          FOR ACCESS TO PUBLIC SWITCHED NETWORK SERVICES.  ALSO KNOWN
          AS LOCAL LOOP.

  ACCESS METHOD:
          THE TECHNIQUE AND/OR THE PROGRAM CODE IN A COMPUTER
          OPERATING SYSTEM THAT PROVIDES INPUT/OUTPUT SERVICES.  THE
          ACCESS METHOD TYPICALLY CARRIES WITH IT AN IMPLIED DATA
          AND/OR FILE STRUCTURE WITH LOGICALLY SIMILAR DEVICES
          SHARING ACCESS METHODS.

  ACCESS TIME:
          THE INTERVAL BETWEEN A REQUEST TO READ OR STORE DATA AND THE
          COMPLETION OF THAT TASK.

  ACD:
          AUTOMATIC CALL DISTRIBUTOR.  SYSTEM DESIGNED TO DISTRIBUTE
          A LARGE VOLUME OF INCOMING CALLS UNIFORMLY TO A NUMBER OF
          OPERATORS OR AGENTS. E.G., FOR AIRLINE RESERVATIONS.

  ACF:
          ADVANCED COMMUNICATIONS FUNCTION.  A SERIES OF SOFTWARE
          PRODUCTS BY IBM THAT SUPPORTS SOPHISTICATED COMPUTER
          NETWORKING FUNCTIONS FOR IBM SYSTEMS AND TERMINALS.

  ACK:
          "ACKNOWLEDGE" CHARACTER.  A TRANSMISSION CONTROL CHARACTER
          TRANSMITTED BY A STATION AS AN AFFIRMATIVE RESPONSE TO THE
          STATION WITH WHICH A CONNECTION HAS BE SET UP.  AN
          ACKNOWLEDGE CHARACTER MAY ALSO BE USED A AN ACCURACY CONTROL
          CHARACTER.

  ACOUSTIC COUPLER:
          A DEVICE THAT CONVERTS ELECTRICAL SIGNALS INTO AUDIO SIGNALS
          ENABLING DATA TO BE TRANSMITTED OVER THE PUBLIC TELEPHONE
          NETWORK VIA A CONVENTIONAL TELEPHONE.

  ACU:
          AUTOMATIC CALLING UNIT.  A DIALING DEVICE SUPPLIED BY THE
          COMMUNICATIONS COMMON CARRIER.

  ADAPTER:
          A CONNECTIVE DEVICE DESIGNED TO LINK DIFFERENT PARTS OF ONE
          OR MORE SYSTEMS AND/OR SUBSYSTEMS.

  ADAPTIVE EQUALIZATION:
          EQUALIZATION THAT IS ADJUSTED WHILE SIGNALS ARE BEING
          TRANSMITTED IN ORDER TO ADAPT TO CHANGING LINE
          CHARACTERISTICS.

  ADAPTIVE ROUTING:
          ROUTING THAT AUTOMATICALLY ADJUSTS TO NETWORK CHANGES SUCH
          AS CHANGES OF TRAFFIC PATTERN OR FAILURES.

  ADC:
          ANALOG-TO-DIGITAL CONVERSION.  A METHOD OF SAMPLING AND
          COSTING AN ANALOG SIGNAL TO CREATE A DIGITAL SIGNAL.

  ADCCP:
          ADVANCED DATA COMMUNICATIONS CONTROL PROCEDURES.  THIS IS
          THE ANSI VERSION OF A BIT-ORIENTED DLC, BSR 3.66.

  ADPCM:
          ADAPTIVE DIFFERENTIAL PULSE CODE MODULATION.  ENCODING
          TECHNIQUE (CCITT) THAT ALLOWS ANALOG VOICE SIGNALS TO BE
          CARRIED ON A 32K BPS DIGITAL CHANNEL.  SAMPLING IS DONE AT
          8KHZ WITH 3 OR 4 BITS USED TO DESCRIBE THE DIFFERENCE
          BETWEEN ADJACENT SAMPLES.

  ADVANCED MOBILE PHONE SERVICE:
          AT&T DEVELOPED ANALOG CELLULAR RADIO STANDARD, ADOPTED IN
          THE USA AND IN MAY OTHER PARTS OF THE WORLD.

  AGCOMNET:
          U.S. DEPARTMENT OF AGRICULTURE'S VOICE AND DATA
          COMMUNICATIONS NETWORK

  ALGORITHM:
          A PRESCRIBED SET OF WELL-DEFINED RULES FOR THE SOLUTION OF A
          PROBLEM IN FINITE NUMBER OF STEPS, EG., A FULL STATEMENT
          OF AN ARITHMETIC PROCEDURE FOR EVALUATING SINE X TO A STATED
          PRECISION.

  ALU:
          ARITHMETIC LOGIC UNIT.  PART OF A COMPUTER THAT PERFORMS
          THE ACTUAL COMPUTATIONS.

  AM:
          AMPLITUDE MODULATION.  A METHOD OF TRANSMISSION WHEREBY THE
          AMPLITUDE OF THE CARRIER FREQUENCY IS MODIFIED IN ACCORDANCE
          WITH THE BIT VALUE OF THE INTELLIGENCE SIGNAL.

  AMBIENT NOISE:
          COMMUNICATONS INTERFERENCE PRESENT IN A SIGNAL PATH AT ALL
          TIMES.

  AMPLIFIER:
          AN ELECTRONIC COMPONENT THAT BOOSTS THE STRENGTH OR
          AMPLITUDE OF A TRANSMITTED, USUALLY ANALOG, SIGNAL;
          FUNCTIONALLY EQUIVALENT TO A REPEATER IN DIGITAL
          TRANSMISSIONS.

  AMPLITUDE:
          MAGNITUDE OR SIZE.  IN WAVE FORMS OR SIGNALS OCCURRING IN A
          DATA TRANSMISSION, A COMPLETE DEFINITION OF THE WAVE FORM
          CAN BE MADE IF THE VOLTAGE LEVEL IS KNOWN AT ALL TIMES.  IN
          THIS CASE, THE VOLTAGE LEVEL IS CALLED THE AMPLITUDE.

  AMPLITUDE MODULATION:
          A METHOD OF TRANSMISSION WHEREBY THE AMPLITUDE OF THE
          CARRIER FREQUENCY IS MODIFIED IN ACCORDANCE WITH THE BIT
          VALUE OF THE INTELLIGENCE SIGNAL.

  ANALOG:
          REFERRING OR PERTAINING TO A SIGNALING TECHNIQUE IN WHICH
          A TRANSMISSION IS CONVEYED BY MODULATING (VARYING) THE
          FREQUENCY, AMPLITUDE, OR PHASE OF A CARRIER.

  ANALOG LOOPBACK:
          TECHNIQUE FOR TESTING TRANSMISSION EQUIPMENT AND DEVICES
          THAT ISOLATE FAULTS TO THE ANALOG SIGNAL RECEIVING OR
          TRANSMITTING CIRCUITRY, WHERE A DEVICE, SUCH AS A MODEM,
          ECHOES BACK A RECEIVED (TEST) SIGNAL THAT IS THEN COMPARED
          WITH THE ORIGINAL SIGNAL.

  ANALOG SIGNAL:
          SIGNAL IN THE FORM OF A CONTINUOUS WAVELIKE PATTERN
          REPRESENTING A PHYSICAL QUANTITY, SUCH AS VOLTAGE, WHICH
          REFLECTS VARIATIONS IN SOME QUANTITY, SUCH AS LOUDNESS OF
          THE HUMAN VOICE.  ANALOG SIGNALING IS GENERIC TO THE PUBLIC
          SWITCHED TELEPHONE NETWORK (PSTN), AS WELL AS TO CERTAIN
          OTHER AUDIO-FREQUENCY AND RADIO-FREQUENCY FACILITIES.

  ANALOG TRANSMISSION:
          TRANSMISSION OF A CONTINUOUSLY VARIABLE SIGNAL AS OPPOSED
          TO A DISCRETELY VARIABLE SIGNAL.

  ANC:
          ALL NUMBER CALLING.  CALLIN BY MEANS OF SEVEN DIGITS INSTEAD
          OF PREVIOUSLY USED TWO LETTERS PLUS FIVE DIGITS.

  ANCILLARY EQUIPMENT:
          TERMINAL OR COMMUNICATIONS DEVICES NOT REQUIRED FOR THE
          PROVISION OF BASIC TELEPHONE SERVICE.  ANSWERING MACHINES,
          CONFERENCING DEVICES, AND AUTOMATIC DIALERS ARE TYPES OF
          ANCILLARY EQUIPMENT.

  ANGLE MODULATION:
          A FORM OF MODULATION IN WHICH THE ANGLE OF A SINE WAVE
          CARRIER IS VARIED.

  ANSI:
          AMERICAN NATIONAL STANDARDS INSTITUTE.  A PRIVATE U.S.
          STANDARDS BODY.

  ANSWERBACK:
          A MANUALLY OR AUTOMATICALLY INITIATED RESPONSE FROM A
          TERMINAL THAT USUALLY INCLLUDES THE TERMINAL ADDRESS TO
          VERIFY THAT THE CORRECT TERMINAL HAS BEEN REACHED AND THAT
          IT IS OPERATIONAL.

  ANTENNA:
          DEVICE USED TO TRANSMIT AND/OR RECEIVE RADIO WAVES.  THE
          PHYSICAL DESIGN OF THE ANTENNA DETERMINES THE FREQUENCY
          RANGE OF TRANSMISSION/RECEPTION.

  APERTURE:
          THE DIAMETER OF A PARABOLIC ANTENNA.

  APL:
          A PROGRAMMING LANGUAGE.  A PROBLEM-SOLVING PROGRAMMING
          LANGUAGE DESIGNED FOR REMOTE TERMINALS; IT OFFERS AN
          EXTENSIVE SET OF OPERATORS AND DATA STRUCTURES FOR HANDLING
          ARRAYS AND PERFORMING MATHEMATICAL FUNCTIONS.

  APLT:
          ADVANCED PRIVATE LINE TERMINATION.  PROVIDES THE PBX USER
          WITH ACCESS TO ALL THE SERVICES OF AN ASSOCIATED ENHANCED
          PRIVATE SWITCHED COMMUNICATIONS SERVICES (EPSCS) NETWORK.
          IT ALSO FUNCTIONS WHEN ASSOCIATED WITH A COMMON CONTROL
          SWITCHING ARRANGEMENT (CCSA) NETWORK.

  APPEND:
          TO CHANGE OR ALTER A FILE OR PROGRAM BY ADDING TO THE END
          OF THE FILE OR PROGRAM.

  APPLICATION LAYER:
          THE TOPE OF THE SEVEN-LAYER OSI MODEL, GENERALLY REGARDED
          AS OFFERING AN INTERFACE TO, AND LARGELY DEFINED BY, THE
          NETWORK USER; IN IBMS SNA, THE END-USER LAYER.

  APPLICATION PROGRAM:
          SOFTWARE PROGRAMS IN A SYSTEM ARE USUALLY KNOWN AS
          "APPLICATION PROGRAMS" AND "SUPERVISORY PROGRAMS."
          APPLICATIONS PROGRAMS CONTAIN NO INPUT/OUTPUT CODING
          (EXCEPT IN THE FORM OF MACROINSTRUCTIONS THAT TRANSFER
          CONTROL TO THE SUPERVISORY PROGRAMS) AND ARE USUALLY
          UNIQUE TO ONE TYPE OF APPLICATION.

  ARCHITECTURE:
          THE PHYSICAL INTER-RELATIONSHIP BETWEEN THE COMPONENTS OF A
          COMPUTER.

  ARCHIVE:
          A PROCEDURE FOR TRANSFERRING INFORMATION FROM AN ONLINE
          STORAGE DISKETTE OR MEMORY AREA TO AN OFF-LINE STORAGE
          MEDIUM.

  ARCNET:
          THE LOCAL NETWORKING PRODUCTS AND PHILOSOPHY DEVELOPED BY
          DATAPOINT CORPORATION.

  ARPA:
          THE GENERIC NAME FOR SERVICES DESIGNED BY THE DEPARTMENT OF
          DEFENSE IN THE 1970S; IT IS NOW A DEFACTO STANDARD FOR
          NETWORKING MULTIVENDOR COMPUTERS RUNNING ON DIFFERING
          OPERATING SYSTEMS.  INCLUDES FTP, SMTP, AND TELNET.

  ARQ:
          AN ERROR CONTROL TECHNIQUE THAT REQUIRES RETRANSMISSION OF A
          DATA BLOCK THAT CONTAINS DETECTED ERRORS.  A SPECIAL FORM,
          CALLED "GO-BACK-N," ALLOWS MULTIPLE BLOCKS TO BE
          ACKNOWLEDGED WITH A SINGLE RESPONSE.  "STOP AND WAIT"
          REQUIRES AN ACKNOWLEDGMENT AFTER EACH BLOCK.

  ARRAY:
          A NAMED, ORDERED COLLECTION OF DATA ELEMENTS THAT HAVE
          IDENTICAL ATTRIBUTES; OR AN ORDERED COLLECTION OF IDENTICAL
          STRUCTURES.

  ARTIFICIAL INTELLIGENCE:
          THE CAPABILITY OF A COMPUTER TO PERFORM SUCH FUNCTIONS THAT
          ARE ASSOCIATED WITH HUMAN LOGIC AS REASONING, LEARNING, AND
          SELF-IMPROVEMENT.

  ARTIFICIAL LANGUAGE:
          A CONVENTION BASED ON A SET OF RULES ESTABLISHED PRIOR TO
          ITS USAGE AND WITHOUT A PRECISE RELATIONSHIP TO THE USER
          APPLICATIONS IT WILL BE USED FOR.

  ASCII:
          AMERICAN STANDARD CODE FOR INFORMATION INTERCHANGE.  THIS IS
          A 7-BIT PLUS PARITY CODE ESTABLISHED BY ANSI TO ACHIEVE
          DATA SERVICES COMPATIBILITY.  ALSO CALLED USASCII.

  ASSEMBLER LANGUAGE:
          A SET OF COMMANDS THAT INCLUDES SYMBOLIC MACHINE LANGUAGE
          STATEMENTS IN WHICH THERE IS A ONE-TO-ONE CORRESPONDENCE
          WITH COMPUTER INSTRUCTIONS.

  ASYNCHRONOUS:
          TRANSMISSION IN WHICH TIME INTERVALS BETWEEN TRANSMITTED
          CHARACTERS MAY BE OF UNEQUAL LENGTH.  TRANSMISSION IS
          CONTROLLED BY START AND STOP BITS WHICH FRAME EACH
          CHARACTER.

  ASYNCHRONOUS COMMUNICATIONS SOFTWARE:
          A SOFTWARE PACKAGE THAT, WHEN USED WITH A MODEM, ALLOWS A
          PC TO COMMUNICATE WITH INFORMATION SERVICES, DATABASES, OR
          HOSTS VIA ASYNCHRONOUS TRANSMISSION OVER THE PUBLIC
          TELEPHONE NETWORK.

  ATB:
          ALL TRUNKS BUSY.  CONDITION IN WHICH ALL TRUNKS IN A GROUP
          ARE ENGAGED.

  ATTENUATION:
          A DECREASE IN THE POWER OF A RECEIVED SIGNAL DUE TO LOSS
          THROUGH LINES, EQUIPMENT, OR OTHER TRANSMISSION DEVICES.
          USUALLY MEASURED IN DECIBELS.

  ATTIS:
          AT&T INFORMATION SYSTEMS; DIVISION OF AT&T TECHNOLOGIES THAT
          SUPPLIED AND MANUFACTURED CUSTOMER PREMISES EQUIPMENT CA.
          1984-86.

  AUDIO FREQUENCIES:
          FREQUENCIES THAT CORRESPOND TO THOSE THAT CAN BE HEARD BY
          THE HUMAN EAR (USUALLY 30HZ TO 20,000HZ).

  AUDIOTEX:
          COMMUNICATIONS SYSTEM THAT ALLOWS A HOST COMPUTER TO PASS
          DATA TO A VOICE MAIL COMPUTER, A STORE-AND-FORWARD
          MECHANISM FOR DIGITIZED VOICE, WHERE IT IS INTERPRETED AND
          DELIVERED OVER THE TELEPHONE.

  AUTO ANSWER:
          AUTOMATIC ANSWERING; CAPABILITY OF A TERMINAL, MODEM,
          COMPUTER, OR SIMILAR DEVICE TO RESPOND TO AN INCOMING CALL
          ON A DIAL-UP TELEPHONE LINE AND TO ESTABLISH A DATA
          CONNECTION WITH A REMOTE DEVICE WITHOUT OPERATOR
          INTERVENTION.  ALLOWS UNATTENDED OPERATION FOR INCOMING
          DIAL-UP CALLS.

  AUTO CALL:
          AUTOMATIC CALLING; A MACHINE FEATURE THAT ALLOWS A
          TRANSMISSION CONTROL UNIT OR A STATION TO AUTOMATICALLY
          INITIATE ACCESS TO A REMOTE SYSTEM OVER A SWITCHED LINE.

  AUTO DIAL:
          AUTOMATIC DIALING.  THE CAPABILITY OF A TERMINAL, MODEM,
          COMPUTER, OR SIMILAR DEVICE TO PLACE A CALL OVER THE
          SWITCHED TELEPHONE NETWORK AND ESTABLISH A CONNECTION
          WITHOUT OPERATOR INTERVENTION.

  AUTOEXECUTE:
          AN OPERATING SYSTEM UTILITY THAT ALLOWS THE PROGRAM TO
          TO AUTOMATICALLY RUN A PROGRAM.

  AUTOVON:
          AUTOMATIC VOICE NETWORK (U.S. MILITARY).

  AVD CIRCUITS:
          ALTERNATE VOICE/DATA CIRCUITS THAT HAVE BEEN CONDITIONED TO
          HANDLE BOTH VOICE AND DATA TRAFFIC.

  BABYPHONE:
          FEATURE ALLOWING CALLS TO AN OFF-HOOK TELEPHONE TO LISTEN TO
          ROOM NOISES, FOR EXAMPLE, TO CHECK IF A BABY IS CRYING.

  BACKBONE NETWORK:
          THE PORTION OF A COMMUNICATIONS FACILITY THAT CONNECTS
          PRIMARY NODES; A PRIMARY SHARED COMMUNICATIONS PATH THAT
          SERVES MULTIPLE USERS VIA MULTIPLEXING AT DESIGNATED
          JUMPING-OFF POINTS.

  BACKHAUL:
          THE TERRESTRIAL LINK BETWEEN AN EARTH STATION AND A
          SWITCHING OR DATA CENTER.

  BACKUP:
          THE PROVISION OF FACILITIES, LOGICAL OR PHYSICAL, TO SPEED
          THE PROCESS OF RESTART AND RECOVERY FOLLOWING FAILURE.

  BALANCED-TO-GROUND:
          WITH A TWO-WIRE CIRCUIT, THE IMPEDANCE-TO-GROUND ON ONE WIRE
          EQUALS THE IMPEDANCE-TO-GROUND ON THE OTHER WIRE.  COMPARE
          WITH UNBALANCED-TO-GROUND, A PREFERABLE CONDITION FOR DATA
          TRANSMISSION.

  BALUN:
          BALANCED/UNBALANCED.  IN THE IBM CABLING SYSTEM, REFERS TO
          AN IMPEDANCE-MATCHING DEVICE USED TO CONNECT BALANCED
          TWISTED-PAIR CABLING WITH UNBALANCED COAXIAL CABLE.

  BANDWIDTH:
          THE DIFFERENCE BETWEEN THE LOWEST AND HIGHEST FREQUENCIES
          TRANSMITTED THROUGH AN ANALOG CHANNEL (I.E., A CHANNEL
          CAPABLE OF TRANSMITTING SIGNALS IN THE RANGE FROM 300 TO
          3300 HZ HAS A BANDWIDTH OF 3000 HZ);  THE MAXIMUM DATA
          TRANSFER RATE OF A DIGITAL CHANEL (A T1 CHANNEL HAS A
          BANDWIDTH OF 1.544 MBPS).

  BASEBAND:
          TRANSMISSION OF A SIGNAL AT ITS ORIGINAL FREQUENCIES,
          WITHOUT MODULATION.

  BASR:
          BUFFERED AUTOMATIC SEND/RECEIVE.

  BATCH MODE:
          APPLICATION PROGRAMS RUN ON THE COMPUTER ONE AT A TIME.  FOR
          EXAMPLE, FINANCIAL TRANACTIONS MAY BE ACCUMULATED FOR A
          WEEK, THEN FED AS A GROUP INTO THE COMPUTER TO UPDATE THE
          GENERAL LEDGER FILES AND TO PRODUCE ACCOUNTING REPORTS.

  BAUD:
          A MEASURE OF SIGNALING SPEED EQUAL TO THE NUMBER OF DISCRETE
          CONDITIONS OR SIGNAL EVENTS PER SECOND.

  BAUD RATE:
          A MEASURE OF SIGNALING SPEED EQUAL TO THE NUMBER OF DISCRETE
          CONDITIONS OR SIGNAL EVENTS PER SECOND.

  BAUDOT:
          A CODE FOR THE TRANSMISSION OF TELEPRINTER DATA, IN WHICH
          FIVE BITS REPRESENT ONE CHARACTER.

  BCC:
          BLOCK CHECK CHARACTER.  THE RESULT OF A TRANSMISSION
          VERFICATION ALGORITHM ACCUMULATED OVER A TRANSMISSION BLOCK,
          AND NORMALLY APPENDED AT THE END OF THE BLOCK; E.G.: CRC OR
          LRC.

  BCD:
          BINARY CODED DECIMAL.  A BINARY-CODED ALPHANUMBERIC NOTATION
          IN WHICH EACH OF THE DECIMAL DIGITS IS REPRESENTED BY A
          BINARY NUMBERAL, E.G., IN BINARY CODE DECIMAL NOTATION THAT
          USES THE WEIGHTS 8-4-2-1, THE NUMBER 23 IS REPRESENTED
          0010 0011.

  BDLC:
          BURROUGHS DATA LINK CONTROL.  A BIT-ORIENTED PROTOCOL
          SIMILAR TO HIGH-LEVEL DATA LINK CONTROL (HDLC).

  BEAM WIDTH:
          ANGULAR WIDTH OF AN ANTENNA RADIATION PATTERN, OR BEAM,
          WITHIN WHICH THE RADIATION EXCEEDS SOME PROPORTION OF THE
          MAXIMUM.

  BENCHMARK:
          A PORINT OF REFERENCE FROM WHICH MEASUREMENTS CAN BE MADE;
          INVOLVES THE USE OF TYPICAL PROBLEMS FOR COMPARING
          PERFORMANCE AND IS OFTER USED IN DETERMINING WHICH COMPUTER
          CAN BEST SERVE A PARTICULAR APPLICATION.

  BER:
          BIT ERROR RATE.  IN DATA COMMUNICATIONS TESTING, THE RATIO
          BETWEEN THE TOTAL NUMBER OF BITS TRANSMITTED IN A GIVEN
          MESSAGE AND THE NUMBER OF BITS IN THAT MESSAGE RECEIVED IN
          ERROR.  A MEASURE OF THE QUALITY OF A DATA TRANSMISSION,
          USUALLY EXPRESSED AS A NUMBER REFERRED TO A POWER OF 10;
          E.G, 1 IN 10 OVER 5.

  BERT:
          BIT ERROR RATE TEST.  A TEST CONDUCTED BY TRANSMITTING A
          KNOWN PATTERN OF BITS (COMMONONLY 63,511, OR 2047 BITS IN
          LENGTH), COMPARING THE PATTERN RECEIVED WITH THE PATTERN
          TRANSMITTED, AND COUNTING THE NUMBER OF BITS RECEIVED IN
          ERROR.

  BETA TEST:
          THE STAGE AT WHICH A NEW PRODUCT IS TESTED UNDER ACTUAL
          CONDITIONS.

  BIDIRECTIONAL PRINTING:
          PRINTING OUTPUT IN TWO DIRECTIONS - LEFT TO RIGHT AND RIGHT
          TO LEFT.  THIS IS FASTER AND SAVES WEAR ON THE PRINTER.

  BINARY:
          THE BASE-2 NUMBER SYSTEM USING ONLY THE SYMBOLS 0 AND 1.
          SINCE 0 AND 1 CAN BE REPRESENTED AS ON AND OFF, OR
          NEGATIVE AND POSITIVE CHARGES, MOST COMPUTERS DO THEIR
          CALCULATIONS IN BINARY.

  BINARY SYNCHRONOUS COMMUNICATIONS:
          AN IBM DEFINED BYTE CONTROLLED COMMUNICATIONS PROTOCOL,
          USING CONTROL CHARACTERS AND SYNCHRONIZED TRANSMISSION
          OF BINARY CODED DATA BETWEEN STATIONS.  ALSON CALLED
          BISYNC.  SIMILAR TO ANSI X3.28 AND ISO 1745.

  BIT:
          AN ABBREVIATION FOR BINARY DIGIT.  IT IS THE AMOUNT OF
          INFORMATION DERIVED FROM KNOWLEDGE OF THE OCCURRENCE OF ONE
          OF TWO EQUIPROBABLE EXCLUSIVE EVENTS, E.G., 0 OR 1.
          THE SMALLEST UNIT OF INFORMATION IN THE BINARY SYSTEM OF
          NOTATION.

  BIT RATE:
          THE SPEED AT WHICH BITS ARE TRANSMITTED, USUALLY EXPRESSED
          IN BITS PER SECOND (BPS).

  BIT-MAPPED:
          REFERS TO A DISPLAY SCREEN ON WHICH A CHARACTER OR IMAGE
          IS GENERATED AND REFRESHED ACCORDING TO A BINARY MATRIX
          (BIT MAP) AT A SPECIFIC LOCATION IN MEMORY.

  BIT-ORIENTED:
          DESCRIBES A COMMUNICATIONS PROTOCOL OR TRANSMISSION
          PROCEDURE WHERE CONTROL INFORMATION IS ENCODED IN FIELDS OF
          ONE OR MORE BITS.  ORIENTED TOWARD FULL-DUPLEX LINK
          OPERATION.

  BITS PER SECOND:
          BPS.  BASIC UNIT OF MEASUREMENT FOR SERIAL DATA TRANSMISSION
          CAPACITY;  ABBREVIATED A K BPS, OR KILOBIT/S, FOR THOUSANDS
          OF BITS PER SECOND; M BPS, OR MEGABIT/S, FOR MILLIONS OF
          BITS PER SECOND; G BITS, OR GIGABIT/S FOR BILLIONS OF BITS
          PER SECOND; T BPS, OR TERABIT/S, TRILLIONS OF BITS PER
          SECOND.

  BLANKING INTERVAL:
          THE AREA IN A VIDEO SIGNAL THAT FALLS BETWEEN FRAMES.  IT IS
          OFTEN USED TO ACCOMMODATE DATA INCLUDING SYNCHRONIZING
          INFORMATION.

  BLERT:
          BLOCK ERROR RATE TEST/TESTER.  A TEST CONDUCTED BY
          TRANSMITTING A KNOWN BLOCKED BIT PATTERN, COMPARING THE
          PATTERN RECEIVED WITH THE PATTERN TRANSMITTED, AND COUNTING
          THE NUMBER OF BLOCKS CONTAINING ERRORED BITS.

  BLOCK:
          A GROUP OF CHARACTERS TRANSMITTED AS A UNIT, OVER WHICH A
          CODING PROCEDURE IS USUALLY APPLIED FOR SYNCHRONIZATION AND/
          OR ERROR CONTROL PURPOSES.

  BLOCK:
          A STRING OF RECORDS, WORDS, OR CHARACTERS TREATED AS A
          LOGICAL ENITY.  BLOCKS ARE SEPARATED BY INTERBLOCK GAPS, AND
          EACH BLOCK MAY CONTAIN ONE OR MORE RECORDS.

  BLOCK CHECK CHARACTER:
          A CONTROL CHARACTER APPENDED TO BLOCKS IN CHARACTER-ORIENTED
          PROTOCOLS.  USED FOR DETERMINING IF THE BLOCK WAS RECEIVED
          IN ERROR IN LONGITUDINAL AND CYCLIC REDUNDANCY CHECKING.

  BLOCK ERROR RATE:
          IN DATA COMMUNICATIONS TESTING, THE RATIO BETWEEN THE TOTAL
          NUMBER OF BLOCKS TRANSMITTED IN A GIVEN MESSAGE AND THE
          NUMBER OF BLOCKS IN THE MESSAGE RECEIVED IN ERROR; A
          MEASURE OF THE QUALITY OF A DATA TRANSMISSION.

  BLOCK LENGTH:
          A MEASURE OF THE SIZE OF A BLOCK, USUALLY SPECIFIED IN UNITS
          SUCH AS RECORDS, WORDS, COMPUTER WORDS, OR CHARACTERS.

  BNA:
          BURROUGHS NETWORK ARCHITECTURE.  A COMMUNICATIONS
          ARCHITECTURE DEVELOPED BY BURROUGHS.

  BOC:
          BELL OPERATING COMPANY.  ANY OF 22 LOCAL TELEPHONE
          COMPANIES SPUN OFF FROM AT&T AS A RESULT OF DIVESTITURE.

  BOC:
          BELL OPERATING COMPANY.

  BOP:
          BIT ORIENTED PROTOCOL.  PROTOCOL USING STANDARD FRAME FORMAT
          ZERO INSERTION AND DELETION, CRC-CCITT, FLAG, ABORT, AND
          IDLE UNIQUE CONTROL BIT PATTERNS AND SYNCRONOUS TRANSMISSION

  BPS:
          BITS PER SECOND TRANSMITTED OR RECEIVED.

  BREAKOUT BOX:
          A DEVICE THAT ALLOWS ACCESS TO INDIVIDUAL POINTS ON A
          PHYSICAL INTERFACE CONNECTOR (E.G. EIA RS-232-C) FOR
          TESTING AND MONITORING.

  BRIDGE:
          1) TO CONNECT A LOAD ACROSS A CIRCUIT.  2) THE CONNECTION
          ITSELF THAT ALLOWS THE INTERCONNECTION OF LANS, PERMITTING
          COMMUNICATION BETWEEN DEVICES ON SEPARATE NETWORKS.

  BROADBAND:
          1)  TRANSMISSION EQUIPMENT AND MEDIA THAT CAN SUPPORT A WIDE
          RANGE OF ELECTROMAGNETIC FREQUENCIES.  2)  ANY VOICE
          COMMUNICATIONS CHANNEL HAVING A BANDWIDTH GREATER THAN A
          VOICE GRADE TELECOMMUNICATIONS CHANNEL;  SOMETIMES USED
          SYNONYMOUSLY WITH WIDEBAND.  3) TYPICALLY THE TECHNOLOGY OF
          CATV (Q.V.) TRANSMISSION, AS APPLIED TO DATA COMMUNICATIONS;
          EMPLOYS COAXIAL CABLE AS THE TRANSMISSION MEDIUM AND RADIO
          FREQUENCY CARRIER SIGNALS IN THE 50 M HZ TO 500M HZ RANGE.

  BROADCAST:
          A TRANSMISSION TO MULTIPLE RECEIVING LOCATIONS
          SIMULTANEOUSLY.  A BROADCAST CAN BE MADE, FOR EXAMPLE,
          OVER A MULTIPOINT LINE TO ALL TERMINALS THAT SHARE THE LINE,
          OR OVER A RADIO OR TELEVISION CHANNEL TO ALL RECEIVERS TUNED
          TO THAT CHANNEL.

  BSC:
          BINARY SYNCHRONOUS COMMUNICATIONS.  AN IBM DEFINED BYTE
          CONTROLLED COMMUNICATIONS PROTOCOL, USING CONTROL CHARACTERS
          AND SYNCHRONIZED TRANSMISSION OF BINARY CODED DATA BETWEEN
          STATIONS.  ALSO CALLED BISYNC.  SIMILAR TO ANSI X3.28 AND
          ISO 1745.

  BTAM:
          BASIC TELECOMMUNICATIONS ACCESS METHOD.  IBM'S LOWEST LEVEL
          I/O MACRO-ROUTINE SUPPORT FOR PROVIDING COMMUNICATIONS
          PROGRAMS ON A HOST COMPUTER.

  BUFFER:
          A STORAGE DEVICE USED TO COMPENSATE FOR THE DIFFERENCE IN
          THE RATE OF DATA FLOW WHEN TRANSMITTING DATA FROM ONE DEVICE
          TO ANOTHER.

  BURST:
          IN DATA COMMUNICATIONS, A SEQUENCE OF SIGNALS COUNTED AS ONE
          UNIT IN ACCORDANCE WITH SOME SPECIFIC CRITERION OR MEASURE.

  BUS:
          1) PHYSICAL TRANSMISSION PATH OR CHANNEL.  TYPICALLY AN
          ELECTRICAL CONNECTION, WITH ONE OR MORE CONDUCTORS, WHEREIN
          ALL ATTACHED DEVICES RECEIVE ALL TRANSMISSIONS AT THE SAME
          TIME.  2) LOCAL NETWORK TOPOLOGY, SUCH AS USED IN ETHERNET
          AND THE TOKEN BUS, WHERE ALL NETWORK NODES LISTEN TO ALL
          TRANSMISSIONS, SELECTING CERTAIN ONES BASED ON ADDRESS
          IDENTIFICATION.  INVOLVES SOME TYPE OF CONTENTION-CONTROL
          MECHANISM FOR ACCESSING THE BUS TRANSMISSION MEDIUM.

  BYTE:
          A BINARY ELEMENT STRING OF 8 BITS, USUALLY OPERATED UPON AS
          A UNIT.

  CAD/CAM:
          COMPUTER-AIDED DESIGN/COMPUTER-AIDED MANUFACTURING; SYSTEMS
          THAT AID IN THE DESIGN OF PRODUCTS AND THEN TRANSFER THE
          INFORMATION TO CONTROL MANUFACTURING EQUIPMENT.

  CARRIER:
          A CONTINUOUS FREQUENCY CAPABLE OF BEING MODULATED OR
          IMPRESSED WITH A SIGNAL.

  CARRIER:
          CXR.  A SIGNAL OF KNOWN CHARACTERISTICS (FOR EXAMPLE,
          FREQUENCY) THAT IS ALTERED (MODULATED) TO TRANSMIT
          INFORMATION.  KNOWING THE EXPECTED SIGNAL, THE RECEIVING
          TERMINAL INTERPRETS ANY CHANGE IN SIGNAL AS INFORMATION.
          CHANGES TO THE SIGNAL MADE BY OUTSIDE INFLUENCES (NOISE) CAN
          CAUSE THE RECEIVING TERMINAL TO MISINTERPRET THE INFORMATION
          TRANSMITTED.

  CARRIER FREQUENCY:
          FREQUENCY OF THE CARRIER WAVE THAT IS MODULATED TO TRANSMIT
          SIGNALS.

  CARRIER SIGNALING:
          ANY OF THE SIGNALING TECHNIQUES USED IN MULTICHANNEL CARRIER
          TRANSMISSION.  THE MOST COMMONLY USED TECHNIQUES ARE
          IN-BAND SIGNALING, OUT-OF-BAND SIGNALING, AND SEPARATE
          CHANNEL SIGNALING.

  CARRIER SYSTEM:
          MEANS OF OBTAINING A NUMBER OF CHANNELS OVER A SINGLE PATH
          BY MODULATING EACH CHANNEL ON A DIFFERENT CARRIER FREQUENCY
          AND DEMODULATING AT THE RECEIVING POINT TO RESTORE THE
          SIGNALS TO THEIR ORIGINAL FREQUENCY.

  CARTERFONE DECISION:
          LANDMARK 1968 FCC DECISION THAT FIRST PERMITTED THE
          ELECTRICAL CONNECTION OF CUSTOMER-OWNED TERMINAL
          EQUIPMENT OT THE TELEPHONE NETWORK.

  CATV:
          COMMUNITY ANTENNA TELEVISION.  1) WHERE TELEVISION RECEPTION
          IS POOR, SIGNALS CAN BE RECEIVED AT A SELECTED SITE BY
          SENSITIVE, DIRECTIONAL ANTENNAS AND THEN TRANSMITTED TO
          SUBSCRIBERS VIA A CABLE NETWORK.  ADDITIONAL CHANNELS, NOT
          NORMALLY AVAILABLE IN THAT AREA, CAN ALSO BE TRANSMITTED.
          2) DATA COMMUNICATIONS BASED ON RADIO FREQUENCY (RF)
          TRANSMISSION MEDIUM.  CATV OFFERS MULTIPLE FREQUENCY-
          DDIVIDED CHANNELS.

  CCIS:
          COMMON CHANNEL INTEROFFICE SIGNALING.  AN ELECTRONIC MEANS
          OF SIGNALING BETWEEN ANY TWO SWITCHING SYSTEMS INDEPENDENT
          OF THE VOICE PATH.  THE USE OF CCIS MAKES POSSIBLE NEW
          CUSTOMER SERVICE, VERSATILE NETWORK FEATURES, MORE FLEXIBLE
          CALL ROUTING, AND FASTER CALL CONNECTIONS.

  CCITT:
          COMITE CONSULTATIF INTERNATIONALE DE TELEGRAPHIC TELEPHONIE.
          AN INTERNATIONAL CONSULTATIVE COMMITTEE WICH SETS
          COMMUNICATION STANDARDS.  THIS COMMITTEE IS RESPONSIBLE
          TO THE ITU WHICH IS A U.N. TREATY ORGANIZATION.

  CCTV:
          CLOSED CIRCUIT TELEVISON.  TELEVISION TRANSMISSION VIA
          DIRECT LINK BETWEEN TWO POINTS, AS OPPOSED TO BROADCAST
          TRANSMISSION TO MANY RECEIVING LOCATIONS.

  CEN:
          EUROPEAN STANDARDS INSTITUTE (COMITE EUROPEEN DE
          NORMALISATION).

  CENLEC:
          EUROPEAN ELECTRICAL STANDARDS INSTITUTE (COMITE EUROPEEN DE
          NORMALISATION ELECTRIQUE).

  CENTREX:
          CENTRAL EXCHANGE;  THE TELEPHONE COMPANY'S TERMINATION POINT
          FOR MULTIPLE LINES FROM CUSTOMERS.  SWITCHING FACILITIES AT
          THE CENTRAL EXCHANGE ALLOW INTERCONNECTION OF THE VARIOUS
          LINES OR CIRCUITS.

  CHANNEL:
          THE PART OF A COMMUNICATIONS SYSTEM THAT CONNECTS A
          COMMUNICATIONS SOURCE TO A MESSAGE SINK.

  CHANNEL CAPACITY:
          A TERM WHICH EXPRESSES THE MAXIMUM DATA RATE WHICH CAN BE
          HANDLED BY THE CHANNEL.

  CHARACTER:
          LETTER, FIGURE, NUMBER, PUNCTUATION, OR OTHER SIGN CONTAINED
          IN A MESSAGE.  BECAUSE DATA IS HANDLED AND TRANSFERRED AS A
          SERIES OF CHARACTERS, THE TERM IS ALSO USED TO MEAN ONE BIT
          PATTERN IN A SPECIFIC DATA CODE.

  CHARACTER ORIENTED PROTOCOL:
          A PROTOCOL IN WHICH A SPEIFIC SET FO COMMUNICATIONS CONTROL
          CHARACTER SEQUENCES CONFIGURE AND MANAGE THE DATA LINK.

  CHIP:
          THE SUBSTRATE UPON WHICH VLSI/LSI CIRCUITS ARE FABRICATED;-
          SOMETIMES USED TO REFER TO THE CIRCUITS ON THE CHIP THEM-
          SELVES.

  CICS:
          CUSTOMER INFORMATION CONTROL SYSTEM.  AN IBM TELEPROCESSING
          MONITOR.

  CIRCUIT:
          1) MEANS OF TWO-WAY COMMUNICATION BETWEEN TWO OR MORE
          POINTS.  2) A GROUP OF ELECTRICAL/ELECTRONIC COMPONENTS
          CONNECTED TO PERFORM A SPECIFIC FUNCTION.

  CIRCUIT SWITCHING:
          TEMPORARY DIRECT CONNECTION OF TWO OR MORE CHANNELS BETWEEN
          TWO OR MORE POINTS IN ORDER TO PROVIDE THE USER WITH
          EXCLUSIVE USE OF AN OPEN CHANNEL WITH WHICH TO EXCHANGE
          INFORMATION.  A DISCRETE CIRCUIT PATH IS SET UP BETWEEN THE
          INCOMING AND OUTGOING LINES, IN CONTRAST TO MESSAGE
          SWITCHING AND PACKET SWITCHING, IN WHICH NO SUCH PHYSICAL
          PATH IS ESTABLISHED.  ALSO CALLED LINE SWITCHING.

  CLADDING:
          IN FIBER OPTIC CABLE, A COLORED, LOW REFRACTIVE INDEX
          MATERIAL THAT SURROUNDS THE CORE AND PROVIDES OPTICAL
          INSULATION AND PROTECTION TO THE CORE.

  CLEAR TO SEND:
          A TIME DELAY INSERTED AFTER A DATA TERMINAL EQUIPMENT
          REQUESTS TO SEND DATA TO ALLOW THE MODEM TO TURN CARRIER
          ON AND TO ESTABLISH EQUALIZATION AND SYNCHRONIZATION.
          ALSO KNOWN AS RTS-CTS DELAY AND TURNAROUND DELAY.

  CLOCKING:
          REPETITIVE, REGULARLY TIMED SIGNALS USED TO CONTROL
          SYNCHRONOUS TRANSMISSIONS.

  CLUSTER CONTROLLER:
          A DEVICE THAT HANDLES THE REMOTE COMMUNICATIONS PROCESSING
          FOR MULTIPLE (USUALLY DUMB) TERMINALS OR WORKSTATIONS.

  CMOS:
          COMPLEMENTARY METAL-OXIDE SEMICONDUCTOR (LOGIC CIRCUIT).

  CO:
          CENTRAL OFFICE.  LOCATION WHERE COMMUNICATIONS COMMON
          CARRIERS TERMINATE CUSTOMER LINES AND HOUSE THE EQUIPMENT
          THAT INTERCONNECTS THESE LINES.

  CO-PROCESSOR:
          AN ADDITIONAL CENTRAL LOGIC UNIT WHICH PERFORMS SPECIFIC
          TASKS WHILE THE MAIN UNIT EXECUTES ITS PRIMARY TASKS.
          FREQUENTLY, THESE CHIPS ARE ADDED TO SPEED UP MATHEMATICAL
          TASKS OR PERFORM I/O FUNCTIONS.

  COBOL:
          COMMON BUSINESS ORIENTED LANGUAGE.  LANGUAGE USED IN
          PROGRAMMING COMPUTERS.

  CODE:
          THE CONVENTIONS SPECIFYING HOW DATA MAY BE REPRESENTED IN A
          PARTICULAR SYSTEM.

  CODEC:
          CODER-DECODER DEVICE USED TO CONVERT ANALOG SIGNALS, SUCH AS
          SPEECH, MUSIC, OR TELEVISION, TO DIGITAL FORM FOR
          TRANSMISSION OVER A DIGITAL MEDIUM, AND BACK AGAIN TO THE
          ORIGINAL ANALOG FORM.  ONE IS REQUIRED AT EACH END OF THE
          CHANNEL.

  COMMON CARRIER:
          AN ORGANIZATION IN THE BUSINESS OF PROVIDING REGULATED
          TELEPHONE, TELEGRAPH, TELEX, AND DATA COMMUNICATIONS
          SERVICES.

  COMMUNICATION:
          TRANSMISSION OF INTELLIGENCE BETWEEN POINTS OF ORIGIN AND
          RECEPTION, WITHOUT ALTERATION OF SEQUENCE OR STRUCTURE OF
          THE CONTENT.

  COMMUNICATION LINE:
          ANY MEDIUM, SUCH AS A WIRE OR A TELEPHONE CIRCUIT, THAT
          CONNECTS REMOTE STATIONS FOR THE PURPOSE OF TRANSMITTING/
          RECEIVING INFORMATION.

  COMMUNICATIONS CONTROLLER:
          DEDICATED COMPUTER WITH SPECIAL PROCESSING CAPABILITIES FOR
          ORGANIZING AND CHECKING DATA AND HANDLING INFORMATION
          TRAFFIC TO AND FROM MANY REMOTE TERMINALS OR COMPUTERS,
          INCLUDING FUNCTIONS SUCH AS MESSAGE SWITCHING.

  COMMUNICATIONS SATELLITE:
          EARTH SATELLITE DESIGNED TO ACT AS A TELECOMMUNICATIONS
          RADIO RELAY AND USUALLY POSITIONED IN GEOSYNCHRONOUS ORBIT
          35,800 KILOMETERS (23,000 MILES) ABOVE THE EQUATOR SO THAT
          IT APPEARS TO BE STATIONARY IN SPACE.

  COMPRESSION:
          THE APPLICATION OF ANY OF SEVERAL TECHNIQUES THAT REDUCE THE
          NUMBER OF BITS REQUIRED TO REPRESENT INFORMATION IN DATA
          STORAGE, THEREFORE CONSERVING BANDWIDTH AND/OR MEMORY.

  COMPUTER NETWORK:
          AN INTERCONNECTION OF COMPUTER SYSTEMS, TERMINALS,
          COMMUNICATONS FACILITIES, AND DATA COLLECTING DEVICES.

  COMSAT:
          COMMUNICATIONS SATELLITE CORPORATION, A PRIVATE U.S. COMPANY
          ESTABLISHED BY STATUTE AS THE EXCLUSIVE INTERNATIONAL
          SATELLITE CARRIER AND REPRESENTING THE U.S. IN INTELSAT.

  CONCENTRATOR:
          A COMMUNICATIONS DEVICE THAT PROVIDES COMMUNICATION
          CAPABILITY BETWEEN MANY LOW-SPEED CHANNELS AND ONE OR MORE
          HIGH-SPEED CHANNELS.

  CONDITIONING:
          THE ADDITION OF EQUIPMENT TO LEASED VOICE-GRADE LINES, TO
          PROVIDE SPECIFIED MINIMUM VALUES OF LINE CHARACTERISTICS
          REQUIRED FOR DATA TRANSMISSION.

  CONDITIONING:
          PROCEDURE TO MAKE TRANSMISSION IMPAIRMENTS OF A CIRCUIT LIE
          WITHIN CERTAIN SPECIFIED LIMITS AND TYPICALLY USED ON
          TELEPHONE LINES LEASED FOR DATA TRANSMISSION TO IMPROVE THE
          POSSIBLE TRANSMISSION SPEED.  TOW TYPE ARE USED:
          C CONDITIONING AND D CONDITIONING.

  CONTENTION:
          A CONDITION ON A COMMUNICATIONS CHANNEL IN WHICH TWO OR
          MORE STATIONS TRY TO TRANSMIT AT THE SAME TIME.

  CONTENTION:
          METHOD OF LINE CONTROL IN WHICH THE TERMINALS REQUEST TO
          TRANSMIT.  IF THE CHANNEL IN QUESTION IS FREE, TRANSMISSION
          PROCEEDS; IF IT IS NOT FREE, THE TERMINAL WILL HAVE TO WAIT
          UNTIL IT BECOMES FREE.  A QUEUE OF CONTENTION REQUESTS CAN
          BE BUILT UP BY A COMPUTER, AND THIS QUEUE CAN EITHER BE
          ORGANIZED IN A PREARRANGED SEQUENCE OR IN THE SEQUENCE IN
          WHICH REQUEST ARE MADE.

  CONTINUITY CHECK:
          IN COMMON-CHANNEL SIGNALING, A TEST PERFORMED TO CHECK THAT
          A PATH EXISTS FOR SPEECH OR DATA TRANSMISSION.

  CONTROL CHARACTER:
          A CHARACTER WHOSE OCCURRENCE IN A PARTICULAR CONTEXT
          INITIATES, MODIFIES, OR STOPS A CONTROL FUNCTION.

  COP:
          CHARACTER ORIENTED PROTOCOL.  A PROTOCOL IN WHICH A SPECIFIC
          SET OF COMMUNICATION CONTROL CHARACTER SEQUENCES CONFIGURE
          AND MANAGE THE DATA LINK.

  CPM:
          CP/M. CONTROL PROGRAM/MICROCOMPUTER; A FAMILY OF OPERATING
          SYSTEMS DEVELOPED BY DIGITAL RESEARCH, INC.

  CRC:
          CYCLIC REDUNDANCY CHECK.  AN ERROR DETECTION SCHEME IN
          WHICH THE BCC IS GENERATED BY TAKING THE REMAINDER AFTER
          DIVIDING ALL THE SERIALIZED BITS IN A BLOCK OF DATA BY A
          PRESET NUMBER.

  CRT:
          CATHODE-RAY TUBE.  A DEVICE SIMILAR TO A TELEVISION PICTURE
          TUB, USED TO DISPLAY TEXTUAL AND GRAPHIC INFORMATION.

  CSMA:
          CARRIER SENSE MULTIPLE ACCESS.  A LOCAL AREA NETWORK ACCESS
          TECHNIQUE IN WHICH MULTIPLE STATIONS CONNECTED TO THE SAME
          CHANNEL ARE ABLE TO SENSE TRANSMISSION ACTIVITY ON THAT
          CHANNEL AND TO DEFER THE INITIATION OF TRANSMISSION WHILE
          THE CHANNEL IS ACTIVE.  SIMILAR TO CONTENTION ACCESS.

  CSMA/CD:
          CARRIER SENSE MULTIPLE ACCESS WITH COLLISION DETECTION.  A
          REFINEMENT OF CSMA IN WHICH STATIONS ARE ABLE TO DETECT THE
          INTERFERENCE CAUSED BY SIMULTANEOUS TRANSMISSIONS BY TWO OR
          MORE STATIONS (COLLISIONS) AND TO RETRANSMIT COLLIDING
          MESSAGES IN AN ORDERLY MANNER.

  CSU:
          CHANNEL SERVICE UNIT.  A COMPONENT OF CUSTOMER PREMISES
          EQUIPMENT (CPE) USED TO TERMINATE A DIGITAL CIRCUIT, SUCH AS
          A DDS OR T1 FACILITY, AT THE CUSTOMER SITE.  PERFORMS
          CERTAIN LINE-CONDITIONING FUNCTIONS, ENSURES NETWORK
          PER FCC RULES, AND RESPONDS TO LOOPBACK COMMANDS FROM THE
          CENTRAL OFFICE.  ALSO, ENSURES PROPER 1'S DENSITY IN A
          TRNAMSITTED BITSTREAM AND PERFORMS BIPOLAR VIOLATION
          CORRECTION.

  CTS:
          CLEAR TO SEND.  A TIME DELAY INSERTED AFTER A DATA TERMINAL
          EQUIPMENT REQUESTS TO SEND DATA TO ALLOW THE MODEM TO TURN
          CARRIER ON AND TO ESTABLISH EQUALIZATION AND SYNCHRONIZATION
          ALSO KNOW AS RTS-CTS DELAY AND TURNAROUND DELAY.

  CURRENT LOOP:
          A TRANSMISSION TECHNIQUE THAT RECOGNIZES CURRENT FLOWS,
          RATHER THAN VOLTAGE LEVELS.  IT HAS TRADITIONALLY BEEN USED
          IN TELETYPEWRITER NETWORKS INCORPORATING BATTERIES AS THE
          TRANSMISSION POWER SOURCE.

  CYCLIC REDUNDANCY CHECK:
          AN ERROR DETECTION SCHEME IN WHICH THE BCC IS GENERATED BY
          TAKING THE REMAINDER AFTER DIVIDING ALL THE SERIALIZED BITS
          IN A BLOCK OF DATA BY A PRESET NUMBER.

  DAISYCHAINING:
          THE CONNECTION OF MULTIPLE DEVICES IN A SERAIL FASHION.  AN
          ADVANTAGE OF DAISYCHAINING IS A SAVINGS IN TRANSMISSION
          FACILITIES.  A DISADVANTAGE IS THAT IF A DEVICE MALFUNCTIONS
          ALL OF THE DEVICES DAISYCHAINED BEHIND IT ARE DISABLED.

  DATA COMMUNICATIONS:
          THE INTERCHANGE OF DATA MESSAGES FROM ONE POINT TO ANOTHER
          OVER COMMUNICATIONS CHANNELS.

  DATA COMMUNICATIONS EQUIPMENT:
          THE EQUIPMENT WHICH PROVIDES THE FUNCTIONS OF INTERFACING
          BETWEEN DATA TERMINAL EQUIPMENT AND A COMMUNICATIONS CHANNEL
          DCE IS NORMALLY A MODEM.

  DATA LINK:
          A TRANSMISSION PATH DIRECTLY CONNECTING TWO OR MORE
          STATIONS.  (A STATION MAY BE A TERMINAL, TERMINAL
          CONTROLLER, FRONT END PROCESSOR, OR OTHER TYPE OF DIGITAL
          EQUIPMENT.)

  DATA LINK:
          ANY SERIAL DATA COMMUNICATIONS TRANSMISSION PATH, GENERALLY
          BETWEEN TWO ADJACENT NODES OR DEVICES AND WITHOUT ANY
          INTERMEDIATE SWITCHING NODES.

  DATA LINK CONTROL:
          A UNIFORM DISCIPLINE FOR THE TRANSMISSION OF DATA OVER A
          SINGLE COMMUNICATIONS LINK.

  DATA LINK ESCAPE:
          THE FIRST CONTROL CHARACTER OF TWO-CHARACTER SEQUENCE USED
          EXCLUSIVELY TO PROVIDE SUPPLEMENTARY LINE-CONTROL SIGNALS.

  DATA SET:
          (1) A MODEM. (2) A COLLECTION OF DATA RECORDS, WITH A
          LOGICAL RELATION OF ONE TO ANOTHER.

  DATA TERMINAL EQUIPMENT:
          THE EQUIPMENT COMPRISING THE DATA SOURCE, DATA SINK, OR
          BOTH.

  DATA TRANSMISSION:
          THE SENDING OF DATA FROM ONE PLACE FOR RECEPTION ELSEWHERE.

  DATAGRAM:
          PACKET OF DATA WHICH CAN BE DELIVERED THROUGH A PACKET
          SWITCHED SYSTEM WITHOUT REFERENCE TO PREVIOUS PACKETS
          ADDRESSED TO THE SAME DESTINATION.

  DATAPHONE DIGITAL SERVICE:
          A COMMUNICATIONS SERVICE OF AT&T IN WHICH DATA IS
          TRANSMITTED IN DIGITAL RATHER THAN ANALOG FORM, THUS
          ELIMINATING REQUIREMENTS FOR MODEM DEVICES.

  DCE:
          DATA COMMUNICATIONS EQUIPMENT.  THE EQUIPMENT WHICH PROVIDES
          THE FUNCTIONS OF INTERFACING BETWEEN DATA TERMINAL EQUIPMENT
          AND A COMMUNICATION CHANNEL.  DCE IS NORMALLY A MODEM.

  DDCMP:
          DIGITAL DATA COMMUNICATIONS MESSAGE PROTOCOL.  THE DEC DATA
          LINK LAYER COMMUNICATIONS PROTOCOL USED TO TRANSMIT MESSAGES
          OVER SYNCHRONOUS, ASYNCHRONOUS, OR PARALLEL FULL OR HALF
          DUPLEX COMMUNICATIONS LINES.

  DDD:
          DIRECT DISTANCE DIALING.  A TELEPHONE EXCHANGE SERVICE WHICH
          ENABLES A USER TO DIAL TELEPHONE NUMBERS OUTSIDE HIS LOCAL
          CALLING AREA WITHOUT OPERATOR ASSISTANCE.

  DDS:
          DATAPHONE DIGITAL SERVICE.  A COMMUNICATIONS SERVICE OF
          AT&T IN WHICH DATA IS TRANSMITTED IN DIGITAL RATHER THAN
          ANALOG FORM, THUS ELIMINATING REQUIREMENTS FOR MODEM DEVICES

  DECIBEL:
          (DB)  UNIT FOR MEASURING RELATIVE STRENGH OF SIGNAL
          PARAMETER SUCH AS POWER OR VOLTAGE.  THE NUMBER OF DECIBELS
          IS 10 TIME THE LOGARITHM (BASE 10) OF THE RATIO OF THE
          POWER OF TWO SIGNALS, OR RATIO OF THE POWER OF ONE SIGNAL TO
          A REFERENCE LEVEL.

  DECNET:
          A DIGITAL EQUIPMENT CORP. PROGRAM PRODUCT BUILT ON DNA
          CONCEPTS IMPLEMENTING DISTRIBUTED PROCESSING FUNCTIONS ON
          DEC MACHINES.

  DELIMITER:
          IN DATA COMMUNICATIONS, A CHARACTER THAT SEPARATES AND
          ORGANIZES ELEMENTS OF DATA.

  DEMARC:
          DEMARCATION POINT BETWEEN CARRIER EQUIPMENT AND CUSTOMER-
          PREMISES EQUIPMENT (CPE); USUALLY A TERMINAL BLOCK.

  DEMODULATION:
          THE PROCESS OF RETRIEVING AND DIGITIZING AN ORIGINAL
          INTELLIGENCE SIGNAL FROM A MODULATED (ANALOG) CARRIER WAVE.

  DES:
          DATA ENCRYPTION STANDARD.  A CRYPTOGRAPHIC ALGORITHM
          DESIGNED BY THE NATIONAL BUREAU OF STANDARDS (NOW THE
          NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY) TO
          ENCYPHER AND DECIPHER DATA USING A 64-BIT KEY.

  DIAGNOSTICS:
          SOFTWARE ROUTINES USED TO CHECK EQUIPMENT MALFUNCTIONS AND
          TO PINPOINT FAULTY COMPONENTS.

  DIGITAL:
          REFERRING TO COMMUNICATIONS PROCEDURES, TECHNIQUES, AND
          EQUIPMENT WHEREBY INFORMATION IS ENCODED AS EITHER BINARY
          "1" OR "0"; THE REPRESENTATION OF INFORMATION IN DISCRETE
          BINARY FORM, DISCONTINUOUS IN TIME, AS OPPOSED TO THE ANALOG
          REPRESENTATION OF INFORMATION IN VARIABLE, BUT CONTINUOUS,
          WAVEFORMS.

  DIP:
          DUAL IN-LINE PACKAGE.

  DIP SWITCH:
          A DUAL IN-LINE SWITCH; ALLOWS THE USER TO SET CURRENT PATHS
          ON OR OFF; THEY ARE FREQUENTLY USED TO RECONFIGURE
          MICROCOMPUTER COMPONENTS AND PERIPHERALS.

  DIRECT DISTANCE DIALING:
          A TELEPHONE EXCHANGE SERVICE WHICH ENABLES A USER TO DIAL
          TELEPHONE NUMBERS OUTSIDE HIS LOCAL CALLING AREA WITHOUT
          OPERATOR ASSISTANCE.

  DISTORTION:
          THE MODIFICATION OF THE WAVEFORM OR SHAPE OF A SIGNAL
          CAUSED BY OUTSIDE INTERFERENCE OR BY IMPERFECTIONS OF THE
          TRANSMISSION SYSTEM.  MOST FORMS OF DISTORTION ARE THE
          RESULT OF THE VARYING RESPONSES OF THE TRANSMISSION SYSTEM
          TO THE DIFFERENT FREQUENCY COMPONENTS OF THE TRANSMISSION
          SIGNAL.

  DLC:
          DATA LINK CONTROL.  A UNIFORM DISCIPLINE FOR THE
          TRANSMISSION OF DATA OVER A SINGLE COMMUNICATIONS LINK.

  DLE:
          DATA LINK ESCAPE.  THE FIRST CONTROL CHARACTER OF TWO-
          CHARACTER SEQUENCE USED EXCLUSIVELY TO PROVIDE SUPPLEMENTARY
          LINE-CONTROL SIGNALS.

  DMI:
          DIGITAL MULTIPLEXED INTERFACE.  GATEWAY PROVIDING 23 DIGITAL
          PCM CHANNELS + 1 SIGNALING CHANNEL AT AN AGGREGATE RATE OF
          1.544M BPS.  DEVELOPED BY AT&T.

  DNA:
          DIGITAL NETWORK ARCHITECTURE.  THE NETWORK ARCHITECTURE OF
          DIGITAL EQUIPMENT CORPORATION.

  DOMSAT:
          DOMESTIC COMMUNICATIONS SATELLITE.

  DOWNLINK:
          THE PORTION OF A SATELLITE CIRCUIT EXTENDING FROM THE
          SATILLITE TO THE EARTH.

  DOWNLOAD:
          THE PROCESS OF LOADING SOFTWARE INTO THE NODES OF A
          NETWORK FROM ONE NODE OVER THE NETWORK MEDIA.

  DOWNTIME:
          THE TOTAL TIME A SYSTEM IS OUT OF SERVICE DUE TO EQUIPMENT
          FAILURE.

  DPNSS:
          A DIGITAL PRIVATE NETWORK SIGNALING SYSTEM STANDARD
          DEVELOPED BY BRITISH TELCOM AND OTHER UNITED KINGDOM PBX
          SUPPLIERS.

  DS1:
          DIGITAL SIGNAL LEVEL 1, A DIGITAL TRANSMISSION FORMAT IN
          WHICH 24 VOICE CHANNELS ARE MULTIPLEXED INTO ON 1.544M BPS
          (US) OR 2.108M BPS (EUROPE) T1 DIGITAL CHANNEL.

  DS2:
          DIGITAL SIGNAL LEVEL2; TELEPHONY TERM DESCRIBING THE 6.312M
          BPS DIGITAL SIGNAL CARRIED ON A T2 FACILITY.

  DS3:
          DIGITAL SIGNAL LEVEL 3; TELEPHONY TERM DESCRIBING THE 44M
          BPS DIGITAL SIGNAL CARRIED ON A T3 FACILITY.

  DS4:
          DIGITAL SIGNAL LEVEL 4; TELEPHONY TERM DESCRIBING THE 273M
          BPS DIGITAL SIGNAL CARRIED ON A T4 FACILITY.

  DSA:
          DISTRIBUTED SYSTEMS ARCHITECTURE.  THE NETWORK ARCHITECTURE
          DEVELOPED BY HONEYWELL.

  DSN:
          DISTRIBUTED SYSTEM NETWORK.  THE NETWORK ARCHITECTURE
          DEVELOPED BY HEWLETT-PACKARD.

  DSO:
          DIGITAL SIGNAL LEVEL 0; TELEPHONY TERM FOR 64K BPS STANDARD
          DIGITAL TELECOMMUNICATIONS SIGNAL OR CHANNEL.

  DSP:
          DISPLAY SYSTEMS PROTOCOL.  IBM PROTOCOL WHICH ALLOWS 3270
          BSL CONTROL UNITS, PRINTERS, TERMINALS, ETC., TO INTERFACE
          WITH PDN.

  DTE:
          DATA TERMINAL EQUIPMENT.  THE EQUIPMENT COMPRISING THE DATA
          SOURCE, DATA SINK, OR BOTH.

  EAROM:
          ELECTRICALLY ALTERABLE READ-ONLY MEMORY.

  EARTH STATION:
          GROUND-BASED EQUIPMENT USED TO COMMUNICATE VIA SATELLITES.

  EBCDIC:
          EXTENDED BINARY CODE DECIMAL INTERCHANGE CODE.  AN 8-BIT
          (256 COMBINATIONS) CHARACTER CODE USED PRIMARILY IN IBM
          EQUIPMENT.

  ECHO:
          WAVE THAT HAS BEEN REFLECTED OR OTHERWISE RETURNED WITH
          SUFFICIENT MAGNITUDE AND DELAY FOR IT TO BE PERCEIVED AS A
          WAVE DISTINCT FROM THAT DIRECTLY TRANSMITTED.

  ECHOPLEX:
          A PROCEDURE WHEREBY THE RECEIVING STATION AUTOMATICALLY
          RETRANSMITS (ECHOS) EACH CHARACTER RECEIVED, SO THAT THE
          SENDER MAY VERIFY THE CORRECTNESS OF HIS TRANSMISSION.

  EEPROM:
          ELECTRICALLY ERASSABLE PROGRAMMABLE READ-ONLY MEMORY.  A
          MEMORY THAT CAN BE ELECTRONICALLY PROGRAMMED AND ERASED, BUT
          WHICH DOES NOT REQUIRE A POWER SOURCE TO RETAIN DATA.

  EIA:
          ELECTRONIC INDUSTRIES ASSOCIATION.  A PRIVATE U.S. STANDARDS
          ORGANIZATION SPECIALIZING IN THE ELECTRICAL AND FUNCTIONAL
          SPECIFICATION OF INTERFACE EQUIPMENT CHARACTERISTICS.

  EIRP:
          EFFECTIVE ISOTROPIC RADIATED POWER.  THE COMBINATION OF
          TRANSMITTED POWER AND ANTENNA GAIN.

  ELECTRONIC INDUSTRIES ASSOCIATION:
          A PRIVATE U.S. STANDARS ORGANIZATION SPECIALIZING IN THE
          ELECTRICAL AND FUNCTIONAL SPECIFICATION OF INTERFACE
          EQUIPMENT CHARACTERISTICS.

  EMI:
          ELECTROMAGNETIC INTERFERENCE.  THE ENERGY GIVEN OFF BY
          ELECTRONIC CIRCUITS AND PICKED UP BY OTHER CIRCUITS; BASED
          ON THE TYPE OF DEVICE AND OPERATING FREQUENCY, EMI CAN BE
          REDUCED BY SHIELDING; MINIMUM ACCEPTABLE LEVELS ARE DETAILED
          BY FCC.

  ENCRYPTION:
          THE PROCESS OF SYSTEMATICALLY ENCODING A BIT STREAM BEFORE
          TRANSMISSION SO THAT AN UNAUTORIZED PARTY CANNOT DECIPHER
          IT.

  END USER:
          THE SOURCE AND/OR DESTINATION OF INFORMATION SENT THROUGH
          THE COMMUNCATIONS SYSTEM; END USERS EXIST AT ALL LEVELS.

  ENQ:
          ENQUIRY.  IN DATA COMMUNICATIONS, A REQUEST FOR A RESPONSE
          FROM ANOTHER TERMINAL; IT IS USED TO OBTAIN IDENTIFICATION
          AND/OR AN INDICATION OF THE OTHER STATION'S STATUS.

  EOM:
          END-OF-MESSAGE.

  EOT:
          END-OF-TAPE.

  EQUALIZATION:
          THE INTRODUCTION OF COMPONENTS TO AN ANALOG CIRCUIT BY A
          MODEM TO COMPENSATE FOR SIGNAL ATTENUATION AND DELAY
          DISTORTION.  GENERALLY, THE HIGHER THE TRANSMISSION RATE,
          THE GREATER THE NEED FOR EQUALIZATION.

  ERGONOMICS:
          A DISCIPLINE THAT PROMOTES THE CONSIDERATION OF HUMAN
          FACTORS IN THE DESIGN OF THE WORKING ENVIORNMENT AND ITS
          COMPONENTS (HEAT, LIGHT, SOUND, EQUIPMENT, ETC.)

  ERROR CONTROL:
          AN ARRANGEMENT WHICH DETECTS THE PRESENCE OF ERRORS.  IN
          SOME SYSTEMS, ERROR CORRECTION OR RECOVER CIRCUITS ARE
          INCLUDED.

  ESA:
          EUROPEAN SPACE AGENCY.

  ESPRIT:
          EUROPEAN STRATEGIC PROGRAM FOR RESEARCH AND DEVELOPMENT IN
          INFORMATION TECHNOLOGIES.

  ETSI:
          EUROPEAN TELECOMMUNICATIONS STANDARDS INSTITUTE.

  EUTELSAT:
          EUROPEAN TELECOMMUNICATIONS SATELLITE ORGANIZATION.
          OPERATES THE EUTELSAT SERVICES OF SATELLITES.

  EXCHANGE:
          ASSEMBLY OF EQUIPMENT IN A COMMUNICATIONS SYSTEM THAT
          CONTROLS THE CONNECTION OF INCOMING AND OUTGOING LINES AND
          INCLUDES THE NECESSARY SIGNALING AND SUPERVISORY FUNCTIONS.
          DIFFERENT EXCHANGES, OR SWITCHES, CAN BE COSITED TO PERFORM
          DIFFERENT FUNCTIONS. E.G., LOCAL EXCHANGE, TRUNK EXCHANGE,
          ETC.  ALSO KNOWN AS CENTRAL OFFICE.

  EXPANDOR:
          TRNASDUCER THAT, FOR A GIVEN AMPLITUDE RANGE OF INPUT
          VOLTAGES, PRODUCES A LARGER RANGE OF OUTPUT VOLTAGES.

  FACSIMILE:
          SYSTEM FOR THE TRANSMISSION OF IMAGES, USUALLY OVER THE
          PUBLIC TELEPHONE NETWORK.  THE IMAGE IS SCANNED AT THE
          TRANSMITTER, RECONSTRUCTED AT THE RECEIVING STATION, AND
          DUPLICATED ON SOME FORM OF PAPER.

  FADING:
          A PHENOMENON, GENERALLY OF MICROWAVE OR RADIO TRANSMISSION,
          WHERE ATMOSPHERIC, ELECTROMAGNETIC, OR GRAVITATIONAL
          INFLUENCES CAUSE A SIGNAL TO BE DEFLECTED OR DIVERTED AWAY
          FROM THE TARGE RECEIVER.  THE REDUCTION IN INTENSITY OF THE
          POWER OF A RECEIVED SIGNAL.

  FAULT:
          A CONDITION THAT CAUSES ANY PHSICAL COMPONENT OF A SYSTEM
          TO FAIL TO PERFORM IN ACCEPTABLE FASHION.

  FAULT TOLERANCE:
          THE ABILITY OF A PROGRAM OR SYSTEM TO OPERATE PROPERLY EVEN
          IF A FAILURE OCCURS.

  FCS:
          CRC REMAINDER TRNASMITTED AT THE END OF A FRAME.

  FDDI:
          FIBER DISTRIBUTED DATA INTERFACE.  AN ANSI STANDARD
          SPECIFYING A PACKET SWITCHED LAN-TO-LAN BACKBONE FOR
          TRANSPORTING DATA A HIGH THROUGHPUT RATES OVER A VARITY OF
          MULTIMODE FIBERS.

  FDM:
          FREQUENCY DIVISION MULTIPLEXING.  DIVIDING THE AVAILABLE
          TRANSMISSION FREQUENCY RANGE INTO NARROWER BANDS, EACH OF
          WHICH IS USED FOR A SEPARATE CHANNEL.

  FDM:
          FREQUENCY-DIVISION MULTIPLEXING.  A TECHNIQUE OF DIVIDING
          A SINGLE COMMUNICATIONS LINE INTO SERVERAL DATA PATHS OF
          DIFFERENT FREQUENCIES, EACH SUPPORTING AN INDEPENDENT
          INFORMATION STREAM.

  FDMA:
          FREQUENCY-DIVISION MULTIPLE ACCESS.  COMMUNICATING DEVICES
          AT DIFFERENT LOCATIONS SHARING A MULTIPOINT OR BROADCAST
          CHANNEL BY MEANS OF A TECHNIQUE THAT ALLOCATES DIFFERENT
          FREQUENCIES TO DIFFERENT USERS.

  FEEDBACK:
          THE RETRUN OF PART OF THE OUTPUT OF A MACHINE, PROCESS, OR
          SYSTEM, TO THE COMPUTER AS INPUT FROM ANOTHER PHASE; ALSO
          REFERS TO SYSTEM MESSAGES THAT KEEP A USER INFORMED OF
          SYSTEM ACTIVITIES DURING A PROCESS.

  FEP:
          FRONT END PROCESSOR.  A DEDICATED COMMUNICATIONS SYSTEM THAT
          INTERCEPTS AND HANDLES ACTIVITY FOR THE HOST.  IT MAY
          PERFORM LINE CONTROL, MESSAGE HANDLING, CODE CONVERSION,
          ERROR CONTROL, AND SUCH APPLICATIONS FUNCTIONS AS
          CONTROL AND OPERATION OF SPECIAL-PURPOSE TERMINALS.

  FIBER OPTICS:
          A TECHNOLOGY THAT USES LIGHT AS A DIGITAL INFORMATION
          CARRIER.  FIBER OPTIC CABLES (LIGHT GUIDES) ARE A DIRECT
          REPLACEMENT FOR CONVENTIONAL COAXIAL CABLES AND WIRE PAIRS.
          THE GLASS-BASED TRANSMISSION FACILITIES OCCUPY FAR LESS
          PHYSICAL VOLUME FOR AN EQUIVALENT TRANSMISSION CAPACITY,
          WHICH IS A MAJOR ADVANTAGE IN CROWDED UNDERGROUND DUCTS.
          THE FIBERS ARE IMMUNE TO ELECTRICAL INTERFERENCE.

  FIFO:
          FIRST-IN, FIRST-OUT.  REFERS TO A METHOD OF COORDINATING THE
          SEQUENTIAL FLOW OF DATA THROUGH A BUFFER.

  FILE SERVER:
          IN LOCAL NETWORKS, A STATION DEDICATED TO PROVIDING FILE
          AND MASS DATA STORAGE SERVICES TO THE OTHER STATIONS ON THE
          NETWORK.

  FILTER:
          CIRCUIT DESIGNED TO TRANSMIT SIGNALS OF FREQUENCIES WITHIN
          ONE OR MORE FREQUENCY BANDS AND TO ATTENUATE SIGNALS OF
          OTHER FREQUENCIES.

  FIPS 1-2:
          CODE FOR INFORMATION INTERCHANGE, ITS REPRESENTATIONS,
          SUBSETS AND EXTENSIONS.
          ANSI X3.4, ANSI X3.32, ANSI X3.41

  FIPS 10-3:
          COUNTRIES, DEPENDENCIES AND AREAS OF SPECIAL SOVEREIGNTY,
          AND THEIR PRINCIPAL ADMINISTRATIVE DIVISIONS.

  FIPS 100-1:
          INTERFACE BETWEEN DATA-TERMINAL EQUIPMENT (DTE) AND DATA
          CIRCUIT TERMINATING EQUIPMENT (DCE) FOR OPERATION WITH
          PACKET-SWITCHED DATA COMMUNICATIONS NETWORKS (PSDN) OR
          BETWEEN TWO DTES BY DEDICATED CIRCUITS.
          ANSI X3.100
          CCITT X.25

  FIPS 103:
          CODES FOR THE IDENTIFICATION OF HYDROLOGIC UNITS IN THE
          UNITED STATES AND THE CARIBBEAN OUTLYING AREAS.
          ANSI X3.145

  FIPS 104-1:
          AMERICAN NATIONAL STANDARD CODES FOR THE REPRESENTATION
          OF NAMES OF COUNTRIES, DEPENDENCIES, AND AREAS OF SPECIAL
          SOVEREIGNTY FOR INFORMATION INTERCHANGE.
          ANSI Z39.27
          ISO 3166

  FIPS 107:
          LOCAL AREA NETWORKS: BASEBAND CARRIER SENSE MULTIPLE ACCESS
          WITH COLLISION DETECTDION ACCESS METHOD AND PHYSICAL LAYER
          SPECIFICATIONS AND LINK LAYER PROTOCOL.
          ANSI/IEEE 802.2
          ANSI/IEEE 802.3

  FIPS 108:
          ALPHANUMERIC COMPUTER OUTPUT MICROFORM QUALITY TEST SLIDE.
          AIIM MS28

  FIPS 109:
          PASCAL.
          ANSI/IEEE 770X3.97

  FIPS 112:
          PASSWORD USAGE.

  FIPS 113:
          COMPUTER DATA AUTHENTICATION.
          ANSI X3.92
          ANSI X9.9

  FIPS 114:
          200 MM (8 IN) FLEXIBLE DISK CARTRIDGE TRACK FORMAT USING
          TWO-FREQUENCY RECORDING AT 6631 BPRAD ON ONE SIDE-1.9 TPMM
          (48 TPI) FOR INFORMATION INTERCHANGE.
          ISO 5654/2

  FIPS 115:
          200 MM (8 IN) FLEXIBLE DISK CARTRIDGE TRACK FORMAT USING
          MODIFIED FREQUENCY MODULATION RECORDING AT 13262 BPRAD ON
          TWO SIDES-1.9 TPMM (48 TPI) FOR INFORMATION INTERCHANGE.
          ISO 7065/2

  FIPS 116:
          130 MM (5.25 IN) FLEXIBLE DISK CARTRIDGE TRACK FORMAT USING
          TWO-FREQUENCY RECORDING AT 3979 BPRAD ON ONE SIDE--1.9
          TPMM (48 TPI) FOR INFORMATION INTERCHANGE.
          ISO 6596/2

  FIPS 117:
          130 MM (5.25 IN) FLEXIBLE DISK CARTRIDGE TRACK FORMAT USING
          MODIFIED FREQUENCY MODULATION RECORDING AT 7958 BPRAD ON
          TWO SIDES--1.9 TPMM (48 TPI) FOR INFORMATION INTERCHANGE.
          ISO 7487/3

  FIPS 118:
          FLEXIBLE DISK CARTRIDGE LABELING AND FILE STRUCTURE FOR
          INFORMATION INTERCHANGE.
          ISO 7665

  FIPS 119:
          ADA.
          ANSI/MIL-STD-1815A

  FIPS 120-1:
          GRAPHICAL KERNEL SYSTEM (GKS).
          ANSI X3.124
          ANSI X3.124.1
          ANSI X3.124.2
          ANSI X3.124.3

  FIPS 121:
          VIDEOTEX/TELETEXT PRESENTATION LEVEL PROTOCOL SYSTAX
          (NORTH AMERICAN PLPS).
          ANSI X3.110/CST500

  FIPS 123:
          SPECIFICATION FOR A DATA DESCRIPTIVE FILE FOR INFORMATION
          INTERCHANGE (DDF).
          ANSI/ISO 8211

  FIPS 125:
          MUMPS.
          ANSI/MDC X11.1

  FIPS 126:
          DATABASE LANGUAGE NDL.
          ANSI X3.133

  FIPS 127-1:
          DATABASE LANGUAGE SQL.
          ANSI X3.135
          ANSI X3.168

  FIPS 128:
          COMPUTER GRAPHICS METAFILE (CGM).
          ANSI X3.122

  FIPS 129:
          OPTICAL CHARACTER RECOGNITION (OCR) DOT MATRIX FOR OCR-MA
          CHARACTER SETS.
          ANSI X3.111

  FIPS 13:
          RECTANGULAR HOLES IN TWELVE-ROW PUNCHED CARDS.
          ANSI X3.21

  FIPS 133:
          CODING AND MODULATION REQUIREMENTS FOR 2400 BIT/SECOND
          MODEMS.

  FIPS 134-1:
          CODEING AND MODULATION REQUIREMENTS FOR 4800 BIT/SECOND
          MODEMS.
          EIA RS-449

  FIPS 135:
          CODEING AND MODULATION REQUIREMENTS FOR DUPLEX 9600 BIT/
          SECOND MODEMS.

  FIPS 136:
          CODEING AND MODULATION REQUIREMENTS FOR DUPLEX 600 AND 1200
          BIT/SECOND MDOEMS.

  FIPS 137:
          ANALOG TO DIGITIAL CONVERSION OF VOICE BY 2400 BIT/SECOND
          LINEAR PREDICTIVE CODING.

  FIPS 138:
          ELECTRICAL CHARACTERISTICS OF BALANCED VOLTAGE DIGITAL
          INTERFACE CIRCUITS.
          EIA RS-422-A

  FIPS 139:
          INTEROPERABILITY AND SECURITY REQUIREMENTS FOR USE OF THE
          DATA ENCRYPTION STANDARD IN THE PHYSICAL LAYER OF DATA
          COMMUNICATIONS.

  FIPS 14-1:
          HOLLERITH PUNCHED CARD CODE.
          ANSI X3.26

  FIPS 140:
          GENERAL SECURITY REQUIREMENTS FOR EQUIPMENT USING THE DATA
          ENCRYPTION STANDARD.

  FIPS 141:
          INTEROPERABILITY AND SECURITY REQUIREMENTS FOR USE OF THE
          DATA ENCRYPTION STANDARD WITH CCITT GROUP 3 FACSIMILE
          EQUIPMENT.

  FIPS 142:
          ELECTRICAL CHARACTERISTICS OF UNBALANCED VOLTAGE DIGITAL
          INTERFACE CIRCUITS.
          EIA RS-423-A

  FIPS 143:
          GENERAL PURPOSE 37-POSITION AND 9-POSITION INTERFACE
          BETWEEN DATA TERMINAL EQUIPMENT AND DATA CIRCUIT-TERMINATING
          EQUIPMENT.
          EIA RS-449

  FIPS 144:
          DATA COMMUNICATIN SYSTEMS AND SERVICES USER-ORIENTED
          PERFORMANCE PARAMETERS.
          ANSI X3.102

  FIPS 146:
          GOSIP: GOVERNMENT OPEN SYSTEMS INTERCONNECTION PROFILE.

  FIPS 147:
          GROUP 3 FACSIMILE APPARATUS FOR DOCUMENT TRANSMISSION.
          EIA RS-465

  FIPS 148:
          PROCEDURES FOR DOCUMENT FACSIMILE TRANSMISSION.
          EIA RS-466

  FIPS 149:
          GENERAL ASPECTS OF GROUP 4 FACSIMILE APPARATUS.
          EIA 536

  FIPS 150:
          FACSIMILE CODING SCHEMES AND CODING CONTROL FUNCTIONS FOR
          GROUP 4 FACSIMILE APPARATUS.
          EIA 538

  FIPS 151-1:
          POSIX: PORTABLE OPERATING SYSTEM INTERFACE FOR COMPUTER
          ENVIORNMENTS.
          IEEE 1003.1/POSIX

  FIPS 152:
          STANDARD GENERALIZED MARKUP LANGUAGE (SGML).
          ISO 8879

  FIPS 153:
          PROGRAMER'S HIERACHICAL GRAPHICS SYSTEM (PHIGS).
          ANSI X3.144
          ANSI X3.144.1

  FIPS 154:
          HIGH SPEED 25 POSTION INTERFACE FOR DATA TERMINAL EQUIPMENT
          AND DATA CIRCUIT-TERMINATING EQUIPMENT.
          EIA 530

  FIPS 155:
          DATA COMMUNICATION SYSTEMS AND SERVICES USER-ORIENTED
          PERFORMANCE MEASUREMENT METHODS.
          ANSI X3.141

  FIPS 156:
          INFORMATION RESOURCES DICTIONARY SYSTEM (IRDS).
          ANSI X3.138

  FIPS 159:
          DETAIL SPECIFICATIONS FOR 62.5 M CODE DIAMETER/125 M
          CLADDING DIAMETER CLASS IA MULTIMO DE GRADED-INDEX
          OPTICAL WAVEGUIDE FIBERS.
          ANSI/EIA/TIA-492.AAAA

  FIPS 16-1:
          BIT SEQUENCING OF CODE FOR INFORMATION INTERCHANGE IN
          SERIAL-BY-BIT DATA TRANSMISSION.
          ANSI X3.15

  FIPS 160:
          C (PROGRAMMING LANGUAGE).
          ANSI X3.159

  FIPS 17-1:
          CHARACTER STRUCTURE AND CHARACTER PARITY SENSE FOR SERIAL-
          BY-BIT DATA COMMUNICATION IN THE CODE FOR INFORMATION
          INTERCHANGE.
          ANSI X3.16

  FIPS 18-1:
          CHARACTER STRUCTURE AND CHARACTER PARITY SENSE FOR PARALLEL-
          BY-BIT DATA COMMUNICATION IN THE CODE FOR INFORMATION
          INTERCHANGE.
          ANSI X3.25

  FIPS 2-1:
          PERFORATED TAPE CODE FOR INFORMATION INTERCHANGE.
          ANSI X3.6

  FIPS 21-3:
          COBOL.
          ANSI X3.23, ANSI X3.23A

  FIPS 22-1:
          SYNCHRONOUS SIGNALING RATES BETWEEN DATA TERMINAL AND DATA
          COMMUNICAITON EQUIPMENT.
          ANSI X3.1

  FIPS 25:
          RECORDED MAGNETIC TAPE FOR INFORMATION INTERCHANGE (1600
          BPI, PHASE ENCODED).
          ANSI X3.39

  FIPS 26:
          ONE-INCH PERFORATED PAPER TAPE FOR INFORMATION INTERCHANGE.
          ANSI X3.18

  FIPS 27:
          TAKE-UP REELS FOR ONE-INCH PERFORATED TAPE FOR INFORMATION
          INTERCHANGE.
          ANSI X3.20

  FIPS 3-1:
          RECORDED MAGNETIC TAPE FOR INFORMATION INTERCHANGE (800
          CPI, NRZI)
          ANSI X3.22

  FIPS 30:
          SOFTWARE SUMMARY FOR DESCRIBING COMPUTER PROGRAMS AND
          AUTOMATED DATA SYSTEMS.

  FIPS 32-1:
          CHARACTER SETS FOR OPTICAL CHARACTER RECOGNITION (OCR).
          ANSI X3.17, ANSI X3.49, ANSI X3.2

  FIPS 33-1:
          CHARACTER SET FOR HANDPRINTING.
          ANSI X3.45

  FIPS 4-1:
          REPRESENTATION FOR CALENDAR DATE AND ORDINAL DATE FOR
          INFORMATION INTERCHANGE.
          ANSI X3.30

  FIPS 46-1:
          DATA ENCRYPTION STANDARD.
          ANSI X3.92

  FIPS 5-2:
          CODES FOR THE IDENTIFICATION OF THE STATES, THE DISTRICT OF
          COLUMBIA AND THE OUTLYING AREAS OF THE UNITED STATES, AND
          ASSOCIATED AREAS.
          ANSI X3.38

  FIPS 50:
          RECORDED MAGNETIC TAPE FOR INFORMATION INTERCHANGE (6250
          CPI, (246 CPMM), GROUP CODED RECORDING).
          ANSI X3.54

  FIPS 51:
          MAGNETIC TAPE CASSETTES FOR INFORMATION INTERCHANGE (3.810
          MM, (0.150 IN), TAPE AT 32 BPMM (800 BPI), PHASE ENCODED).
          ANSI X3.48

  FIPS 52:
          RECORDED MAGNETIC TAPE CARTRIDGE FOR INFORMATION
          INTERCHANGE, 4 TRACK, 6.30 MM (1/4 IN) 63 BPMM (1600 BPI)
          PHASE ENCODED.
          ANSI X3.56

  FIPS 53:
          TRANSMITTAL FORM FOR DESCRIBING COMPUTER MAGNETIC TAPE FILE
          PROPERTIES.

  FIPS 54-1:
          COMPUTER OUTPUT MICROFORM (COM) FORMATS AND REDUCTION
          RATIOS, 16MM AND 105MM.
          ANSI/AIIM MS5
          ANSI/AIIM MS14

  FIPS 58-1:
          REPRESENTATIONS OF LOCAL TIME OF THE DAY FOR INFORMATION
          INTERCHANGE.
          ANSI X3.43

  FIPS 59:
          REPRESENTATIONS OF UNIVERSAL TIME, LOCAL TIME DIFFERENTIALS
          AND UNITED STATES TIME ZONE REFERENCES FOR INFORMATION
          INTERCHANGE.
          ANSI X3.51

  FIPS 6-4:
          COUNTIES AND COUNTY EQUIVALENTS OF THE STATES OF THE UNITED
          STATES AND THE DISTRICT OF COLUMBIA.
          ANSI X3.31

  FIPS 66:
          STANDARD INDUSTRIAL CLASSIFICATION (SIC) CODES.

  FIPS 68-2:
          BASIC.
          ANSI X3.113

  FIPS 69-1:
          FORTRAN.
          ANSI X3.9

  FIPS 70-1:
          REPRESENTATION OF GEOGRAPHIC POINT LOCATIONS FOR INFORMATION
          INTERCHANGE.
          ANSI X3.61

  FIPS 71:
          ADVANCED DATA COMMUNICATION CONTROL PROCEDURES (ADCCP).
          ANSI X3.66

  FIPS 79:
          MAGNETIC TAPE LABELS AND FILE STRUCTURE FOR INFORMATION
          INTERCHANGE.
          ANSI X3.27

  FIPS 8-5:
          METROPOLITAN STATISTICAL AREAS (MSAS) INCLUDING CMSAS,
          PMSAS AND NECMAS.

  FIPS 81:
          DES MODES OF OPERATION.
          ANSI X3.106

  FIPS 84:
          MICROFILM READERS.
          ANSI/AIIM (NMA) MS20

  FIPS 85:
          OPTICAL CHARACTER RECOGNITION (OCR) INKS.
          ANSI X3.86

  FIPS 86:
          ADDITIONAL CONTROLS FOR USE WITH ASCII.
          ANSI X3.64

  FIPS 89:
          OPTICAL CHARACTER RECOGNITION (OCR) CHARACTER POSITIONING.
          ANSI X3.93M

  FIPS 9-1:
          CONGRESSIONAL DIRSTICTS OF THE UNITED STATES.

  FIPS 93:
          PARALLEL RECORDED MAGNETIC TAPE CARTRIDGE FOR INFORMATION
          INTERCHANGE, 4-TRACK 6.30 MM (1/4 INCH), 63 BPMM (1600
          BPI), PHASE ENCODED.
          ANSI X3.72

  FIPS 95:
          CODES FOR THE IDENTIFICATION OF FEDERAL AND FEDERALLY-
          ASSISTED ORGANIZATIONS.

  FIRMWARE:
          PERMANENT OR SEMIPERMANENT CONTROL CODING IMPLEMENTED AT A
          MICRO-INSTRUCTION LEVEL FOR AN APPLICATION PROGRAM,
          INSTRUCTION SET, OPERATING ROUTINE, OR SIMILAR
          USER-ORIENTED FUNCTION.

  FLAG SEQUENCE:
          (HDLC,SDLC,ADCCP).  THE UNIQUE SEQUENCE OF EIGHT BITS
          (01111110) EMPLOYED TO DELIMIT THE OPENING AND CLOSING OF A
          FRAME.

  FLOW CONTROL:
          A FUNCTION FOR THE CONTROL OF THE DATA FLOW WITHIN A LAYER
          BETWEEN PEER ENTITIES OR BETWEEN ADJACENT LAYERS.

  FLOW CONTROL:
          THE USE OF BUFFERING AND OTHER MECHANISMS, SUCH AS CONTROLS
          THAT TURN A DEVICE ON AND OFF, TO PREVENT DATA LOSS DURING
          TRANSMISSION.

  FM:
          FREQUENCY MODULATION.  A METHOD OF TRANSMISSION WHEREBY THE
          FREQUENCY OF THE CARRIER WAVE IS CHANGED TO CORRESPOND TO
          CHANGES IN THE BIT VALUE OF THE INFORMATION SIGNAL.

  FM:
          FREQUENCY MODULATION.  ONE OF THREE WAYS OF MODIFYING A SINE
          WAVE SIGNAL TO MAKE IT CARRY INFORMATION.  THE SINE WARE OR
          "CARRIER" HAS ITS FREQUENCY MODIFIED IN ACCORDANCE WITH THE
          INFORMATION TO BE TRANSMITTED.  THE FREQUENCY FUNCTION OF
          THE MODULATED WAVE MAY BE CONTINUOUS OR DISCONTINUOUS.

  FOOTPRINT:
          1) THE SPACE A DEVICE OCCUPIES ON A DESK OR WORK SURFACE.
          2) IN SATELLITE COMMUNICATIONS, THE FOOTPRINT IS THE PRECISE
          AREA OF THE EARTH IN WHICH THE SIGNAL CAN BE RECEIVED.  A
          GIVEN SATELLITE CAN HAVE A FOOTPRINT OF UP TO SEVERAL MILES
          IN WIDTH.

  FORTRAN:
          FORMULA TRANSLATION.  LANGUAGE USED IN PROGRAMMING
          COMPUTERS.

  FOTS:
          FIBER OPTIC TRANSMISSION SYSTEMS.

  FOUR-WIRE:
          FOUR-WIRE CIRCUIT.  COMMUNICATIONS PATH IN WHICH FOUR WIRES
          (TWO FOR EACH DIRECTION OF TRANSMISSION) ARE CONNECTED TO
          THE STATION EQUIPMENT.

  FOUR-WIRE CHANNEL:
          A CIRCUIT CONTAINING TWO PAIRS OF WIRE (OR THEIR LOGICAL
          EQUIVALENT) FOR SIMULTANEOUS (I.E, FULL-DUPLEX) TWO-WAY
          TRANSMISSION.

  FOUR-WIRE CIRCUIT:
          A CIRCUIT IN WHICH TWO PAIRS OF CONDUCTORS, ONE FOR THE
          INBOUND CHANNEL AND ONE FOR THE OUTBOUND CHANNEL, ARE
          CONNECTED TO THE STATION EQUIPMENT.

  FRAME:
          (HDLC,SDLC,ADCCP).  THE SEQUENCE OF CONTIGUOUS BITS,
          BRACKETED BY AND INCLUDING OPENING AND CLOSING FLAG
          SEQUENCES.  A VALID FRAME CONTAINS AT LEAST 32 BITS BETWEEN
          FLAGS AND CONTAINS AN ADDRESS FIELD, A CONTROL FIELD AND A
          FRAME CHECK SEQUENCE.  A FRAME MAY OR MAY NO INCLUDE AN
          INFORMATION FIELD.

  FRAME CHECK SEQUENCE:
          CRC REMAINDER TRANSMITTED AT THE END OF A FRAME.

  FREQUENCY:
          AN EXPRESSION HOW FREQUENTLY A PERIODIC (REPETITIOUS) WAVE
          FORM OR SIGNAL REGENERATES ITSELF AT A GIVEN AMPLITUDE.  IT
          CAN BE EXPRESSED IN HERTZ (HZ), KILOHERTZ (KHZ), MEGAHERTZ
          (MHZ), ETC.

  FREQUENCY DIVISION MULTIPLEXING:
          DEVIDING THE AVAILABLE TRANSMISSION FREQUENCY RANGE INTO
          NARROWER BANDS, EACH OF WHICH IS USED FOR A SEPARATE
          CHANNEL.

  FREQUENCY MODULATION:
          A METHOD OF TRANSMISSION WHEREBY THE FREQUENCY OF THE
          CARRIER WAVE IS CHANGED TO CORRESPOND TO CHANGES IN THE BIT
          VALUE OF THE INFORMATION SIGNAL.

  FREQUENCY SHIFT KEYING:
          A METHOD OF FREQUENCY MODULATION IN WHICH A "1" IS
          REPRESENTED AS ONE FREQUENCY AND "0" AS ANOTHER FREQUENCY.

  FRONT END PROCESSOR:
          A COMMUNICATIONS COMPUTER ASSOCIATED WITH (CHANNEL ATTACHED
          TO) A HOST COMPUTER.

  FSK:
          FREQUENCY SHIFT KEYING.  A METHOD OF FREQUENCY MODULATION
          IN WHICH A "1" IS REPRESENTED AS ONE FREQUENCY AND A "0" AS
          ANOTHER FREQUENCY.

  FSK:
          FREQUENCY SHIFT KEYING.  A METHOD OF MODULATION THAT USES
          TWO DIFFERENT FREQUENCIES TO DISINGUISH BETWEEN A MARK
          (DIGITAL 1) AND A SPACE (DIGITAL 0) WHEN TRANSMITTING ON
          AN ANALOG LINE.  USER IN MODEMS OPERATING AT 1200 BPS OR
          SLOWER.

  FTP:
          FILE TRANSFER PROTOCOL.  A SERVICE PROVIDING A FAMILY OF
          COMMANDS FOR PERFORMING FILE AND DIRECTORY OPERATIONS OVER
          THE NETWORK, SUCH AS APPEND, RENAME AND DELETE FILES, LIST
          CHANGE, MAKE AND REMOVE DIRECTORIES, CHECK STATUS, TOGGLE
          SWITCHES, AND ASK FOR HELP.

  FULL DUPLEX:
          SIMULTANEOUS INDEPENDENT TRANSMISSION IN BOTH DIRECTIONS.

  FX:
          FOREIGN EXCHANGE.  CONNECTS A CUSTOMER'S LOCATION TO A
          REMOTE EXCHANGE.  THIS SERVICE PROVIDES THE EQUIVALENT OF
          LOCAL SERVICE FROM THE DISTANT EXCHANGE.

  GATEWAY:
          A CONCEPTUAL OR LOGICAL NETWORK STATION THAT SERVES TO
          INTERCONNECT TWO OTHERWISE INCOMPATIBLE NETWORKS, NETWORK
          NODES, SUBNETWORKS, OR DEVICES.  GATEWAYS PERFORM A PROTOCOL
          CONVERSION OPERATION ACROSS A WIDE SPECTRUM OF
          COMMUNICATIONS FUNCTIONS OR LAYERS.

  GEOSYNCHRONOUS ORBIT:
          A COMMUNICATION SATELLITE ORBIT WHERE THE SATELLITE ROTATES
          IN THE SAME DIRECTION THE EARTH ROTATES, AND ITS ROTATION
          SPEED IS SUCH THAT THE SATELLITE APPEARS STATIONARY OVER THE
          SAME EARTH LOCATION.  THE ORBIT IS ABOUT 22,300 MILES ABOVE
          THE EQUATOR TO ACHIEVE THIS DESIRED RELATIONSHIP.

  GHZ:
          GIGAHERTZ.  ONE BILLION CYCLES PER SECOND.

  GIGA:
          ONE BILLION.

  GIGAHERTZ:
          GHZ.  A FREQUENCY UNIT EQUAL TO ONE BILLION CYCLES PER
          SECOND.

  GOSIP:
          U.S. AND U.K. GOVERNMENT OSI PROCUREMENT SPECIFICATION

  HALF DUPLEX:
          TRANSMISSION IN EITHER DIRECTION, BUT NOT BOTH DIRECTIONS
          SIMULTANEOUSLY.

  HAND SHAKING:
          THE EXCHANGE OF PREDETERMINED SIGNALS FOR PURPOSES OF
          CONTROL WHEN A CONNECTION IS ESTABLISHED BETWEEN TWO DATA
          SETS.

  HDLC:
          HIGH LEVEL DATA LINK CONTROL.  ISO VERSION OF A BIT ORIENTED
          DATA LINK CONTROL.  FUNCTIONALLY SIMILAR TO ADCCP.

  HEADER:
          THE CONTROL INFORMATION PREFIXED IN A MESSAGE TEXT, E.G.,
          SOURCE OR DESTINATION CODE, PRIORITY, OR MESSAGE TYPE.

  HEADER:
          THE INITIAL PORTION OF A MESSAGE, WHICH CONTAINS ANY
          INFORMATION AND CONTROL CODES THAT ARE NOT PART OF THE TEST
          (E.G., ROUTINE, PRIORITY, MESSAGE TYPE, DESTINATION
          ADDRESSEE, AND TIME ORIGINATION).

  HERTZ:
          A UNIT OF FREQUENCY EQUAL TO ONE CYCLE PER SECOND.
          ABBREVIATED HZ.

  HERTZ:
          (HZ).  UNIT OF ELECTROMAGNETIC FREQUENCY EQUAL TO ONE CYCLE
          PER SECOND.

  HEURISTIC:
          EXPLORATORY METHODS OF PROBLEM SOLVING IN WHICH SOLUTIONS
          ARE ARRIVED AT BY AN INTERACTIVE, SELF-LEARNING METHOD.

  HEXADECIMAL:
          REFERRING TO A NUMBER SYSTEM WITH 16 MEMBERS REPRESENTED BY
          0 THROUGH 9 FOLLOWED BY A THROUGH F.  USED TO IDENTIFY THE
          16 POSSIBLE BIT PATTERNS OF HALF-BYTE; TWO HEX DIGITS
          REPRESENT ONE BYTE.  SYNONYMOUS WITH HEX.

  HF:
          HIGH FREQUENCY.  PORTION OF THE ELECTROMAGNETIC SPECTRUM,
          TYPICALLY USED IN SHORT-WAVE RADIO APPLICATIONS;
          FREQUENCIES APPROXIMATELY IN THE DMHZ TO 30 MHZ RANGE.

  HIGH LEVEL DATA LINK CONTROL:
          ISO VERSION OF A BIT ORIENTED DATA LINK CONTROL.
          FUNCTIONALLY SIMILAR TO ADCCP.

  HISTOGRAM:
          A GRAPH OF CONTIGUOUS VERTICAL BARS REPRESENTING A FREQUENCY
          DISTRIBUTION IN WHICH THE GROUPS OR CLASSES OF ITEMS ARE
          MARKED AT EQUAL INTERVALS IN ASCENDING ORDER ON THE X AXIS,
          AND THE NUMBER OF ITEMS IN EACH CLASS IS INDICATED BY A
          HORIZONTAL LINE SEGMENT DRAWN ABOVE THE X AXIS AT A HEIGHT
          EQUAL TO THE NUMBER OF ITEMS IN THE CLASS.

  HOST COMPUTER:
          A COMPUTER ATTACHED TO A NETWORK PRIMARILY PROVIDING
          SERVICES SUCH A COMPUTATION, DATA BASE ACCESS, SPECIAL
          PROGRAMS, OR PROGRAMMING LANGUAGES.

  IDN:
          INTERGRATED DIGITAL NETWORK.  NETWORK EMPLOYING BOTH DIGITAL
          SWITCHES AND DIGITAL TRANSMISSION.

  IEEE:
          INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS.  A GROUP
          INVOLVED IN RECOMMENDING STANDARDS FOR THE COMPUTER AND
          COMMUNICATIONS FIELD.

  INFRARED:
          PERTAINING TO THE FREQUENCY RANGE IN THE ELECTROMAGNETIC
          SPECTRUM THAT IS HIGHER THAN RADIO FREQUENCIES BUT BELOW
          THE RANGE OF VISIBLE LIGHT.

  INMARSAT:
          INTERNATION MARITIME SATELLITE ORGANIZATION.  ITS WORK NOW
          INCREASINGLY COVERS AERONAUTICAL AND MOBILE, AS WELL AS
          MARITIME, SATELLITE COMMUNICATIONS.

  INTERNATIONAL STANDARDS ORGANIZATION:
          ANSI IN A MEMBER OF ISO.  A PRIVATE INTERNATIONAL BODY
          WHICH RECOMMENDS STANDARDS IN A WIDE VARIETY OF FIELDS
          FROM PHOTOGRAPHIC FILM TO DATA COMMUNICATIONS.

  INTUG:
          INTERNATIONAL TELECOMMUNICATIONS USERS GROUP.

  IP:
          INTERNET PROTOCOL.  PROVIDES A COMMON LAYER OVER DISIMILAR
          NETWORKS.  IT CONTROLS COMMUNICATIONS BETWEEN TWO SPU'S
          RESIDING ON TWO OR MORE DIFFERENT NETWORKS.

  ISO:
          INTERNATIONAL STANDARDS ORGANIZATION.  ANSI IS A MEMBER OF
          ISO.  A PRIVATE INTERNATIONAL BODY WHICH RECOMMENDS
          STANDARDS IN A WIDE VARIETY OF FIELDS FROM PHOTOGRAPHIC FILM
          TO DATA COMMUNICATIONS.

  JACK:
          A DEVICE USED GENERALLY FOR TERMINATING THE PERMANENT WIRING
          OF A CIRCUIT, ACCESS TO WHICH IS OBTAINED BY THE INSERTION
          OF A PLUG.

  JITTER:
          SLIGHT MOVEMENT OF A TRANSMISSION SIGNAL IN TIME OR PHASE
          THAT CAN INTRODUCE ERRORS AND LOSS OF SYNCHRONIZATION FOR
          HIGH-SPEED SYNCHRONOUS COMMUNICATIONS.

  JUMPER:
          PATCH CABLE OR WIRE USED TO ESTABLISH A CIRCUIT, OFTEN
          TEMPORARILY, FOR TESTING OR DIAGNOSTICS.

  K:
          THE SYMBOL FOR 2, RAISED TO THE TENTH POWER (KILO), EQUAL TO
          1,024.

  KILOBYTE:
          1,024 BYTES.

  KILOHERTZ:
          KHZ.  ONE THOUSAND CYCLES PER SECOND.

  LAN:
          LOCAL AREA NETWORK.  A HIGH-VOLUME TRANSMISSION FACILITY
          INTERCONNECTING A NUMBER OF DATA DEVICES, GENERALLY WITHIN
          THE SAME BUILDING OR A CAMPUS.

  LAP:
          LINK ACCESS PROTOCOL.  THE UNBALANCED VERSION OF HDLC IN
          WHICH THE COMMUNICATIONS LINE WILL HAVE A SINGLE, PERMANENT
          CONTROL STATION WHICH MUST INITIATE ALL DATA TRANSFER
          ACTIONS.

  LAPB:
          LINK ACCESS PROTOCOL-BALANCED.  A VERSION OF HDLC IN WHICH
          THE COMMUNICATION LINE HAS NO SINGLE CONTROLLER, AND EITHER
          OF THE TWO CONNECTED STATIONS MAY INITIATE A DATA TRANSFER
          OPERATION.

  LASER:
          ACRONYM FOR "LIGHT AMPLIFICATION BY STIMULATED EMISSON OF
          RADIATION. "  LASERS CONVERT ELECTRICAL ENERGY INTO RADIANT
          ENERGY IN THE VISIBLE OR INFRARED PARTS OF THE SPECTRUM,
          EMITTING LIGHT WITH A SMALL SPECTRAL BANDWIDTH.  FOR THIS
          REASON, THEY ARE WIDELY USED IN FIBER OPTIC COMMUNICATIONS,
          PARTICULARLY AS SOURCES FOR LONG-HAUL LINKS.

  LAYERING:
          THAT ASSECT OF A NETWORK ARCHITECTURE WHICH SEPARATES
          FUNCTIONS INTO DISTINCT FUNCTIONAL LEVELS WHICH COMMUNICATE
          INDIVIDUALLY WITH LIKE LEVELS IN A DISTANT NODE.

  LCD:
          LIQUID CRYSTAL DISPLAY.  A GRAPHIC DISPLAY ON A TERMINAL
          SCREEN USING AN ELECTROLUMINESCENT TECHNOLOGY TO FORM
          SYMBOLS OR SHAPES.

  LDM:
          LIMITED DISTANCE MODEM.  A LOWER COST MODEM INTENDED FOR
          LIMITED DISTANCE OPERATION.  ALSO CALLED SHORT HAUL MODEM.

  LEASED LINE:
          A LINE RESERVED FOR THE EXCLUSIVE USE OF A LEASING CUSTOMER.
          ALSO CALLED PRIVATE LINE.

  LED:
          LIGHT-EMITTING DIODE.  SEMICONDUCTOR JUNCTION DIODE THAT
          EMITS RADIANT ENERGY AND IS USED AS A LIGHT SOURCE FOR
          FIBER OPTIC COMMUNICATIONS, PARTICULARLY FOR SHORT-HAUL
          LINKS.  ALSO USED IN ALPHANUMERIC DISPLAYS IN ELECTRONIC
          TELEPHONES AND CALCULATORS.

  LIMITED DISTANCE MODEM:
          A LOWER COST MODEM INTENDED FOR LIMITED DISTANCE OPERATION.
          ALSO CALLED SHORT HAUL MODEM.

  LINK:
          THE PHYSICAL INTERCONNECTON BETWEEN TWO SYSTEMS (SOMETIMES
          CALLED NODES) IN A NETWORK.  A LINK MAY CONSIST OF A DATA
          COMMUNICATIONS CIRCUIT OR A DIRECT CHANNEL (CABLE)
          CONNECTION.

  LINK ACCESS PROTOCOL:
          THE UNBALANCED VERSION OF HDLC IN WHICH THE COMMUNICATIONS
          LINE WILL HAVE A SINGEL, PERMANENT CONTROL STATION WHICH
          MUST INITIATE ALL DATA TRANSFER ACTIONS.

  LINK ACCESS PROTOCOL BALANCED:
          A VERSION OF HDLC IN WHICH THE COMMUNICATION LINE HAS NO
          SINGLE CONTROLLER, AND EITHER OF THE TWO CONNECTED STATIONS
          MAY INITIATE A DATA TRANSFER OPERATION.

  LINK LAYER:
          THE LOGICAL ENTITY IN THE OSI MODEL CONCERNED WITH
          TRANSMISSION OF DATA BETWEEN ADJACENT NETWORK NODES: IT IS
          THE SECOND LAYER PROCESSING IN THE OSI MODEL, BETWEEN THE
          PHYSICAL AND THE NETWORK LAYERS.

  LINK PROTOCOL:
          A SET OF RULES FOR DATA COMMUNICATION OVER A DATA-LINK
          SPECIFIED IN TERMS OF TRANSMISSION CODE, TRANSMISSION MODE,
          CONTROL PROCEDURES AND RECOVERY PROCEDURES.

  LISP:
          AN INTERPRETIVE LANGUAGE DEVELOPED FOR MANIPULATION OF
          SYMBOLIC STRINGS AND RECURSIVE DATA; WHILE THE LANGUAGE HAS
          BEEN DEVELOPED TO AID IN THE HANDLING OF SYMBOLIC LISTS, IT
          CAN BE AND HAS BEEN USED SUCCESSFULLY IN THE MANUPULATION
          OF MATHEMATICAL AND ARITHMETIC LOGIC.

  LOCAL AREA NETWORK:
          A HIGH-VOLUME DATA TRANSMISSION FACILITY INTERCONNECTING A
          NUMBER OF DATA DEVICES, GENERALLY WITHIN A BUILDING OR A
          CAMPUS.

  LONGITUDINAL REDUNDANCY CHECK:
          A SYSTEM OF ERROR CONTROL BASED ON TRANSMISSION OF A BLOCK
          CHECK CHARACTER BASED ON PRESET RULES.  THE CHECK CHARACTER
          FORMATION RULE IS APPLIED IN THE SAME MANNER TO EACH
          CHARACTER ON A BIT BY BIT BASIS.

  LPM:
          LINES PER MINUTE.  A REFERENCE TO PRINTER SPEEDS.

  LRC:
          LOGITUDINAL REDUNDANCY CHECK.  A SYSTEM OF ERROR CONTROL
          BASED ON TRANSMISSION OF A BLOCK CHECK CHARACTER BASED ON
          PRESET RULES.  THE CHECK CHARACTER FORMATON RULE IS APPLIED
          IN THE SAME MANNER TO EACH CHARACTER ON A BIT BY BIT BASIS.

  MAGNETIC CORE:
          MATERIAL USED TO STORE DATA IN MAIN MEMORY.

  MAGNETIC DISK:
          A FLAT CIRCULAR PLATE WHERE DATA CAN BE STORED; THE
          INFORMATION IS ACCESSIBLE TO READING AND WRITING HEADS ON AN
          ARM WHICH CAN BE MOVED TO A DESIRED STORAGE AREA AS THE
          PLATE ROTATES.

  MAGNETIC TAPE:
          FLEXIBLE PLASTIC MATERIAL MAGNETICALLY COATED ON ONE SIDE TO
          STORE INFORMATION.

  MARK:
          PRESENCE OF A SIGNAL.  IN TELEGRAPHY, MARK REPRESENTS THE
          CLOSED CONDITION OR CURRENT FLOWING.  EQUIVALENT TO A BINARY
          ONE CONDITION.

  MASTER CONTROL PROGRAM:
          A PART OF THE BURROUGHS OPERATING SYSTEM WHICH MONITORS THE
          HOST'S OPERATION.

  MBPS:
          MEGABITS PER SECOND.

  MCP:
          MASTER CONTROL PROGRAM.  A PART OF THE BURROUGHS OPERATING
          SYSTEM WHICH MONITORS THE HOST'S OPERATION.

  MEDIA:
          THE VEHICLES THAT STORE OR TRANSMIT INFORMATION, CLASSIFIED
          AS SOURCE, INPUT, AND OUTPUT.

  MEDIUM:
          1) THE MATERIAL ON WHICH DATA IS RECORDED; FOR EXAMPLE,
          MAGNETIC TYPE, DISKETTE.  2) ANY MATERIAL SUBSTANCE THAT IS,
          OR CAN BE, USED FOR THE PROPAGATION OF SIGNALS, USUALLY IN
          THE FORM OF MODULATED RADIO, LIGHT, OR ACOUSTIC WAVES, FROM
          ONE POINT TO ANOTHER, SUCH AS OPTICAL FIBER, CABLE, WIRE,
          DIELECTRIC SLAB, WATER, ARI, OR FREE SPACE.

  MEGA:
          ONE MILLION.

  MICR:
          MAGNETIC INK CHARACTER RECOGNITION.  SPECIAL ENCODED SYMBOLS
          THAT CAN BE READ AND CONVERTED TO DIGITAL INFORMATION FOR A
          COMPUTER; GENERALLY USED ON CHECKS AND DEPOSIT SLIPS.

  MICRO:
          ONE MILLIONTH.

  MICROCOMPUTER:
          A SMALL-SCALE PROGRAMMABLE MACHINE THAT PROCESSES
          INFORMATION; IT GENERALLY HAS A SINGEL CHIP AS ITS CENTRAL
          PROCESSING UNIT AND INCLUDES STORAGE AND INPUT/OUTPUT
          FACILITIES IN THE BASIC UNIT.

  MICROFICHE:
          A RECTANGULAR SHEET OF TRANSPARENT FILM THAT CONTAINS
          MULTIPLE ROWS OF GREATLY REDUCED PAGE IMAGES OF REPORT,
          CATALOGS, RATE BOOKS, ETC.

  MICROFILM:
          A SMALL ROLL OF PHOTOGRAPHIC FILM WHICH CAN HOLD SEVERAL
          THOUSAND DOCUMENT PAGES WHICH, WHEN PROJECTED ONTO A
          SCREEN, PRODUCES A LEGIBLE COPY OF THE ITEM OR FORM
          PHOTOGRAPHED.

  MICROPROCESSOR:
          THE CENTROL UNIT OF A MICROCOMPUTER THAT CONTAINS THE
          LOGICAL ELEMENTS FOR MANIPULATING AND PREFORMING
          ARITHMETICAL AND LOGICAL OPERATIONS ON INFORMATION.

  MICROWAVE:
          1) PORTION OF THE ELECTROMAGNETIC SPECTRUM ABOVE ABOUT
          760 MHZ.  2) DESCRIBING HIGH-FREQUENCY TRANSMISSION SIGNALS
          AND EQUIPMENT THAT EMPLOY MICROWAVE FREQUENCIES, INCLUDING
          LINE-OF-SIGHT OPEN-AIR MICROWAVE TRANSMISSION AND,
          INCREASINGLY, SATELLITE COMMUNICATIONS.

  MILLI:
          ONE-THOUSANDTH.

  MINICOMPUTER:
          SMALL- TO MEDIUM-SCALE PROGRAMMABLE MACHINE THAT PROCESSES
          INFORMATION; GENERALLY THE MIDRANGE BETWEEN MICROCOMPUTERS
          AND MAINFRAMES, SOME CAN SUPPORT UP TO SEVERAL HUNDRED
          USER TERMINALS SIMULTANEOUSLY.

  MNEMONIC:
          A SYMBOLIC NAME GIVEN TO PROGRAMS, DATA, AND INSTRUCTIONS;
          FOR EXAMPLE, ART FOR ARITHMETIC EXPRESSION, MPY FOR
          MULTIPLY, AND VNDMSTFLE FOR VENDOR MASTER FILE.

  MNP:
          MICROCOM NETWORKING PROTOCOL.  AN ERROR-CORRECTION METHOD
          BASED ON THE OSI REFERENCE MODEL THAT RETRANSMITS LOST OR
          CORRUPT DATA IN PACKETS OF INFORMATION.  THE PROTOCOL WAS
          ORIGINALLY DEVELOPED IN 1982 BY GREGORY PEARSON OF MICROCOM
          AND NOW CONSISTS OF NINE SEPARATE CLASSES.  MNP SUPPORTS
          INTERACTIVE AND FILE TRANSFER APPLICATIONS OVER DIAL-UP
          LINES AT TRANSFER RATES UP TO 38.4K BPS.

  MODEM:
          (MODULATOR-DEMODULATOR)  A DEVICE THAT MODULATES AND
          DEMODULATES SIGNALS TRANSMITTED OVER COMMUNICATIONS
          CIRCUITS.  ALSO CALLED DATA SET.

  MODEM PAIR DELAY:
          THE ONE WAY DELAY ADDED BY A PAIR OF MODEMS TO THE
          PROPAGATION DELAY ON A COMMUNICATIONS LINE.

  MOS:
          METAL OXIDE SEMICONDUCTOR.  A COMMON MATERIAL AND METHOD
          FOR MAKING INTERGRATED CIRCUITS.

  MOTHERBOARD:
          THE CENTRAL CARD OF A COMPUTER; IT FEATURES FEMALE
          CONNECTORS THAT ACCEPT OTHER PRINTED CIRCUIT CARDS.

  MOUSE:
          A HANDHELD DEVICE, SEPARATE FROM A KEYBOARD, USED TO
          CONTROL THE POSITION INDICATOR ON A DISPLAY SCREEN; AS THE
          DEVICE IS ROLLED ALONG A TABLETOP, ITS RELATIVE POSITION
          APPROXIMATES THE POSITION OF THE INDICATOR.

  MS-DOS:
          MICROSOFT DISK OPERATING SYSTEM; A MASTER CONTROL PROGRAM
          FOR 16 BIT SYSTEM.

  MTBF:
          MEAN-TIME-BETWEEN-FAILURE.  AVERAGE LENGTH OF TIME FOR
          WHICH THE SYSTEM, OR COMPONENT OF THE SYSTEM, WORKS WITHOUT
          FAULT.

  MTTR:
          MEAN-TIME-TO-REPAIR.  THE AVERAGE TIME REQUIRED TO PERFORM
          CORRECTIVE MAINTENANCE ON A FAILED DEVICE.

  MULTIACCESS:
          THE ABILITY FOR SEVERAL USERS TO COMMUNICATE WITH A
          COMPUTER AT THE SAME TIME.

  MULTIBUS:
          INTEL'S CENTRAL PATH (CHANNEL) FOR TRANSMITTING ELECTRICAL
          SIGNALS AND DATA; IT WAS DEVELOPED FOR USE IN 8- AND 16-BIT
          COMPUTER SYSTEMS.

  MULTILEAVING:
          THE TRANSMISSION OF A VARIABLE NUMBER OF DATASTREAMS BETWEEN
          USER DEVICES AND A COMPUTER, USUALLY VA BISYNC FACILITIES
          AND USING BISYNC PROTOCOLS.

  MULTIPLEXER:
          MUX.  A DEVICE THAT ENABLES MORE THAN ONE SIGNAL TO BE SENT
          SIMULTANEOUSLY OVER ONE PHYSICAL CHANNEL.  IT COMBINES
          INPUTS FROM TWO OR MORE TERMINALS, COMPUTER PORTS, OR OTHER
          MULTIPLEXERS, AND TRANSMITS THE COMBINED DATASTREAM OVER A
          SINGLE HIGH-SPEED CHANNEL.  AT THE RECEIVING END, THE
          HIGH-SPEED CHANNEL IS DEMULTIPLEXED, EITHER BY ANOTHER
          MULTIPLEXER OR BY SOFTWARE.

  MULTIPLEXING:
          A DIVISION OF A TRANSMISSION FACILITY INTO TWO OR MORE
          CHANNELS.  SEE: FREQUENCY DIVISION MULTIPLEXING AND TIME
          DIVISION MULTIPLEXING.

  MULTIPLEXING:
          DIVISION OF A TRANSMISSION FACILITY INTO TWO OR MORE
          CHANNELS EITHER BY SPLITTING THE FREQUENCY BAND TRANSMITTED
          BY THE CHANNEL INTO NARROWER BANDS, EACH OF WHICH IS USED
          TO CONSTITUTE A DISTINCT CHANNEL (FREQUENCY-DIVISION
          MULTIPLEX), OR BY ALLOTTING THIS COMMON CHANNEL TO SEVERAL
          DIFFERENT INFORMATION CHANNELS, ONE AT A TIME (TIME-DIVISION
          MULTIPLEXING).

  MULTIPOINT:
          PERTAINING OR REFERRING TO A COMMUNICATIONS LINE TO WHICH
          THREE OR MORE STATIONS ARE CONNECTED.  IT IMPLIES THAT THE
          LINE PHYSICALLY EXTENDS FROM ONE STATION TO ANOTHER UNTIL
          ALL ARE CONNECTED.

  MULTIPOINT LINE:
          A SINGLE COMMUNCATIONS LINE TO WHICH MORE THAN ONE TERMINAL
          IS ATTACHED.  ALSO CALLED MULTI-DROP.

  MULTIPROCESSING:
          SIMULTANEOUS APPLICATION OF MORE THAN ONE PROCESSOR IN A
          MULTI-CPU COMPUTER SYSTEM TO THE EXECUTION OF A SINGLE USER
          JOB, WHICH IS POSSIBLE ONLY IF THE JOB CAN BE EFFECTIVELY
          DEFINED IN TERMS OF A NUMBER OF INDEPENDENTLY EXECUTABLE
          COMPONENTS.

  MULTIPROCESSOR:
          A COMPUTER SYSTEM WITH TWO OR MORE CENTRAL COMPUTERS UNDER
          COMMON CONTROL.

  MULTIPROGRAMMING:
          A TECHNIQUE ALLOWING SEVERAL PROGRAMS TO RUN ON ONE COMPUTER
          SYSTEM AT THE SAME TIME.

  MULTITASKING:
          TWO OR MORE PROGRAM SEGMENTS RUNNING IN A COMPUTER AT THE
          SAME TIME.

  MULTITHREADING:
          CONCURRENT PROCESSING OF MORE THAN ONE MESSARE (OR SIMILAR
          SERVICE REQUEST) BY AN APPLICATION PROGRAM.

  MULTIUSER:
          A COMPUTER THAT CAN SUPPORT SEVERAL WORKSTATION OPERATING
          SIMULTANEOUSLY.

  NAK:
          NEGATIVE ACKNOWLEDGMENT.  AN INDICATION THAT A PREVIOUS
          TRANSMISSION WAS IN ERROR AND THE RECEIVER IS READY TO
          ACCEPT RETRANSMISSION.

  NANO:
          ONE-BILLIONTH.

  NANOMETER:
          ONE-BILLIONTH OF A METER.

  NANOSECOND:
          ONE-BILLIONTH OF A SECOND.

  NARUC:
          NATIONAL ASSOCIATION OF REGULATORY UTILITY COMMISSIONERS.

  NATA:
          NORTH AMERICAN TELECOMMUNICATIONS ASSOCIATION.

  NCCF:
          NETWORK COMMUNICATIONS CONTROL FACILITY (IBM,SNA).  ALONG
          WITH NPDA THIS PROGRAM PRODUCT ALLOWS FOR THE MONITORING
          OF A COMPLETE SNA NETWORK FROM A CENTRAL LOCATION.

  NCP:
          NETWORK CONTROL PROGRAM (IBM,SNA).  THE PROGRAM WHICH
          RESIDES IN THE COMMUNICATIONS CONTROLLER PERFORMING ALL
          ROUTING, LINE CONTROL, AND BUFFERING FUNCTIONS FOR THE
          COMMUNICATION LINES FOR WHICH IT IS RESPONSIBLE.

  NEPER:
          BASIC UNIT OF A LOGARITHMIC SCAL USED FOR THE EXPRESSION OF
          RATIOS OF VOLTAGES, CURRENTS, AND SIMILAR QUANTITIES.

  NETIPC:
          NETWORK INTERPROCESS COMMUNICATIONS.  PERMITS INTER-CPU
          PROGRAM SHARING AND ALLOWS PROGRAMS RUNNING ON DIFFERENT
          SYSTEMS TO EXCHANGE DATA THROUGH A SET OF PROGRAMMATIC
          CALLS.  THIS PEER-TO-PEER SERVICE IS IMPORTANT FOR
          DEVELOPING DISTRIBUTED APPLICATIONS.

  NETWORK LAYER:
          IN THE OSI MODEL, THE LOGICAL NETWORK ENITY THAT SERVICES
          THE TRANSPORT LAYER.  IT IS RESPONSIBLE FOR ENSURING THAT
          DATA PASSED TO IT FROM THE TRANSPORT LAYER IS ROUTED AND
          DELIVERED THROUGH THE NETWORK.

  NFS:
          NETWORK FILE SYSTEM.  AN INDUSTRY STANDARD FOR REMOTE FILE
          ACCESS ACROSS A COMMON NETWORK; IT ALLOWS WORKSTATIONS TO
          SHARE FILE SYSTEMS IN A MULTIVENDOR NETWORK OF MACHINES
          AND OPERATING SYSTEMS.  INCLUDES RFS, RPC, XDR, AND YP.

  NFT:
          NETWORK FILE TRANSFER.  COPIES FILES BETWEEN ANY TWO NODES
          ON A NETWORK, EITHER INTERACTIVELY OR PROGRAMMATICALLY.
          ALLOWS USER TO 1) COPY REMOTE FILE, 2) TRANSLATE FILE
          ATTRIBUTES, AND 3) ACCESS REMOTE ACCOUNTS.

  NPDA:
          NETWORK PROBLEM DETERMINATION APPLICATION.  A PROGRAM
          PRODUCT WHICH ALONG WITH NCCP ALLOWS FOR THE MONITORING OF
          AN ENTIRE NETWORK FROM A SINGEL LOCATION, COLLECTION OF
          STATISTICS, AND ISOLATION OF COMMUNICATION FAULTS.

  OCR:
          OPTICAL CHARACTER RECOGNITION.  A LIGHT-SENSITIVE SCANNING
          PROCESS WHERE A DEVICE PRECEIVES ACTUAL CHARACTER IMAGES
          AND CONVERTS THEM INTO DIGITAL CODE.

  OPTICAL DISKS:
          STORAGE DEVICES THAT USE LASER TECHNOLOGY TO RECORD DATA;
          THEY FEATURE GREATER STORAGE CAPACITY THAN MAGNETIC DISKS
          BUT DO NOT ALLOW DATA TO BE OVER-WRITTEN.

  OSI:
          OPEN SYSTEMS INTERCONNECTION.  REFERRING TO THE REFERENCE
          MODEL, OSI IS A LOGICAL STRUCTURE FOR NETWORK OPERATIONS
          STANDARDIZED WITHIN THE OSI; A SEVEN-LAYER NETWORK
          ARCHITECTURE BEING USED FOR THE DEFINITION OF NETWORK
          PROTOCOL STANDARDS TO ENABLE ANY OSI-COMPATIBLE COMPUTER OR
          DEVICE TO COMMUNICATE WITH ANY OTHER OSI-COMPLIANT COMPUTER
          OR DEVICE FOR A MEANINGFUL EXCHANGE OF INFORMATION.

  PABX:
          PRIVATE AUTOMATIC BRANCH EXCHANGE.

  PACKET:
          A GROUP OF BITS INCLUDING DATA AND CONTROL ELEMENTS WHICH
          IS SWITCHED AND TRANSMITTED AS A COMPOSITE WHOLE.
          IMPLEMENTED IN CCITT X.25 PROTOCOL.

  PACKET SWITCHED NETWORK:
          A NETWORK DESIGNED TO CARRY DATA IN THE FORM OF PACKETS.
          THE PACKET AND ITS FORMAT IS INTERNAL TO THAT NETWORK.  THE
          EXTERNAL INTERFACES MAY HANDLE DATA IN DIFFERENT FORMATS,
          AND CONVERSION IS DONE BY AN INTERFACE COMPUTER.

  PACKET SWITCHING:
          A DATA TRANSMISSION PROCESS, UTILIZING ADDRESSED PACKETS,
          WHEREBY A CHANNEL IS OCCUPIED ONLY FOR THE DURATION OF
          TRANSMISSION OF THE PACKET.

  PAD:
          PACKET ASSEMBLE/DISASSEMBLER.  A PROTOCOL CONVERSION DEVICE
          OR PROGRAM THAT PERMITS END-USER DEVICES (E.G., TERMINALS)
          TO ACCESS A PACKET SWITCHED NETWORK.

  PAM:
          PULSE AMPLITUDE MODULATION.  FORM OF MODULATION IN WHICH
          THE AMPLITUDE OF THE PULSE CARRIER IS VARIED IN ACCORDANCE
          WITH SUCCESSIVE SAMPLES OF THE MODULATING SIGNAL.

  PARALLEL TRANSMISSION:
          METHOD OF DATA TRANSFER IN WHICH ALL BITS OF A CHARACTER
          OR BYTE ARE TRANSMITTED SIMULTANEOUSLY.

  PARITY:
          A CONSTANT STATE OR EQUAL VALUE.  PARITY CHECKING IS ONE OF
          THE OLDEST ERROR CHECKING TECHNIQUES.  CHARACTER BIT
          PATTERNS ARE FORCED INTO PARITY (TOTAL NUMBER OF ONE BITS,
          ODD OR EVEN) BY ADDING ONE OR ZERO BIT, AS APPROPRIATE, AS
          THEY ARE TRANSMITTED; THE PARITY (ODD OR EVEN) IS THEN
          VERIFIED UPON RECEIPT BY THE RECEIVING DEVICE.

  PARITY BIT:
          A CHECK BIT APPENDED TO AN ARRAY OF BINARY DIGITS TO MAKE
          THE SUM OF ALL THE BINARY DIGITS, INCLUDING THE CHECK BIT,
          ALWAYS ODD OR ALWAYS EVEN.

  PARITY CHECK:
          ADDITON OF NON-INFORMATION BITS TO DATA, MAKING THE NUMBER
          OF ONES IN EACH GROUPING OF BITS EITHER ALWAYS ODD FOR ODD
          PARITY OR ALWAYS EVEN FOR EVEN PARITY.  USED FOR ERROR
          DETECTION PURPOSES.

  PBX:
          PRIVATE BRANCH EXCHANGE.  A TELEPHONE SWITCH LOCATED ON A
          CUSTOMER'S PREMISES THAT PRIMARILY ESTABLISHES VOICE-GRADE
          CIRCUITS, OVER TIE-LINES BETWEEN INDIVIDUAL USERS AND THE
          SWITCHED TELEPHONE NETWORK.  TYPICALLY, THE PBX ALSO
          PROVIDES SWITCHING WITHIN A CUSTOMER PREMISES' LOCAL AREA
          AND USUALLY OFFERS NUMBEROUS OTHER ENHANCED FEATURES, SUCH
          AS LEAST-COST ROUTING AND CALL-DETAIL RECORDING.

  PDN:
          PUBLIC DATA NETWORK.  A NETWORK DESIGNED PRIMARILY FOR DATA
          TRANSMISSION AND INTENDED FOR SHARING BY MANY USERS FROM
          MANY ORGANIZATIONS.

  PHASE MODULATION:
          A METHOD OF TRANSMISSION WHEREBY THE ANGLE OF PHASE OF THE
          CARRIER WAVE IS VARIED IN ACCORDANCE WITH THE SIGNAL.

  PM:
          PHASE MODULATION.  A METHOD OF TRANSMISSION WHEREBY THE
          ANGLE OF PHASE OF THE CARRIER WAVE IS VARIED IN ACCORDANCE
          WITH THE SIGNAL.

  POINT TO POINT:
          A NETWORK CONFIGURATION IN WHICH A CONNECTION IS ESTABLISHED
          BETWEEN TWO, AND ONLY TWO, TERMINAL INSTALLATIONS.  AS
          OPPOSED TO MULTIPOINT.

  POLLING:
          THE PROCESS OF INVITING ANOTHER STATION OR NODE TO TRANSMITT
          DATA.

  POLLING:
          A METHOD OF CONTROLLING THE SEQUENCE OF TRANSMISSION BY
          TERMINALS ON A MULTIPOINT LINE BY REQUIRING EACH TERMINAL TO
          WAIT UNTIL THE CONTROLLING PROCESSOR REQUESTS IT TO
          TRANSMIT.

  PRESENTATION LAYER:
          IN THE OSI MODEL, THAT LAYER OF PROCESSING THAT PROVIDES
          SERVICES TO THE APPLICATION LAYER, ALLOWING IT TO INTERPRET
          THE DATA EXCHANGED, AS WELL AS TO STRUCTURE DATA MESSAGES TO
          BE TRANSMITTED IN A SPECIFIC DISPLAY AND CONTROL FORMAT.

  PRIVATE LINE:
          SEE LEASED LINE.

  PROCESS:
          PERFORMING OPERATIONS ON INFORMATION.

  PROCESSOR:
          A COMPUTER CAPABLE OF RECEIVING INFORMATION, MANIPULATING
          IT, AND SUPPLYING RESULTS.

  PROGAGATION DELAY:
          THE ONE WAY DELAY INTRODUCED BY THE TIME IT TAKES AN
          ELECTRICAL IMPULSE TO TRAVEL ALONG A PHYSICAL TRANSMISSION
          LINE OR THROUGH SPACE.

  PROGRAM:
          A GROUP OF INSTRUCTIONS THAT DIRECT A COMPUTER'S TASKS.

  PROGRAMMER:
          A PERSON WHO DESIGNS, WRITES, AND TESTS COMPUTER PROGRAMS.

  PROM:
          PROGRAMMABLE READ-ONLY MEMORY.  AN INFORMATION STORATE AREA
          THAT CAN BE RECORDED BY AN OPERATOR; INFORMATION STORED
          THERE CAN ONLY BE ALTERED THROUGH SPECIAL PHYSICAL
          PROCESSES.

  PROMPTING:
          MESSAGES FROM A COMPUTER THAT GIVE INSTRUCTIONS TO THE USER.

  PROTOCOL:
          A FORMAL SET OF CONVENTIONS OR RULES GOVERNING THE FORMAT,
          TIMING, AND ERROR CONTROL TO FACILITATE MESSAGE EXCHANGE
          BETWEEN TWO COMMUNICATING PROCESSES.

  PROTOCOL CONVERSION:
          THE PROCESS OF TRANSLATING THE PROTOCOL NATIVE TO AN
          END-USER DEVICE (E.G, A TERMINAL) INTO A DIFFERENT PROTOCOL
          (E.G., ASCII TO BSC), ALLOWING THAT END-USER DEVICE TO
          COMMUNICATE WITH ANOTHER DEVICE (E.G., A COMPUTER) WITH
          WHICH IT WOULD OTHERWISE BE INCOMPATIBLE.  PROTOCOL
          CONVERSION CAN BE PERFORMED BY A DECICATED DEVICE, BY A
          SOFTWARE PACKAGE LOADED ONTO AN EXISTING SYSTEM, SUCH AS A
          GENERAL-PURPOSE COMPUTER, FRONT-END PROCESSOR, OR PBX SYSTEM

  PSTN:
          PUBLIC SWITCHED TELEPHONE NETWORK.  THE COMPLETE PUBLIC
          TELEPHONE SYSTEM, INCLUDING TELEPHONES, LOCAL AND TRUNK
          LINES, AND EXCHANGES.

  PUBLIC DATA NETWORK:
          A NETWORK DESIGNED PRIMARILY FOR DATA TRANSMISSION AND
          INTENDED FOR SHARING BY MANY USERS FROM MANY ORGANIZATIONS.

  PULSE CODE MODULATON:
          DIGITAL MODULATION IN WHICH THE MESSAGE IS REPRESENTED
          BY A CODED GROUP.  A TYPE OF A/D CONVERSION.

  RAM:
          RANDOM-ACCESS MEMORY.  A STORAGE TECHNIQUE IN WHICH THE
          TIME REQUIRED TO OBTAIN DATA IS INDEPENDENT OF THE LOCATION.

  REDUNDANCY:
          1) PORTION OF THE TOTAL INFORMATION CONTAINED IN A MESSAGE
          THAT CAN BE ELIMINATED WITHOUT LOSS OF ESSENTIAL
          INFORMATION.  2) PROVISION OF DUPLICATE, BACKUP EQUIPMENT TO
          IMMEDIATELY TAKE OVER THE FUNCTION OF EQUIPMENT THAT FAILS.
          3) IN A DATABASE, THE STORAGE OF THE SAME DATA ITEM OR
          GROUP OF ITEMS IS TWO OR MORE FILES.

  RESPONSE TIME:
          THE AMOUNT OF TIME ELAPSED BETWEEN A GENERATION OF AN
          INQUIRY AT A TERMINAL AND RECEIPT OF A RESPONSE AT THAT
          SAME TERMINAL.

  RF:
          RADIO FREQUENCY.  A FREQUENCY THAT IS HIGHER THAN THE AUDIO
          FREQUENCIES BUT BELOW THE INFRARED FREQUENCIES, USUALLY
          ABOVE 20KHZ.

  RFI:
          RADION FREQUENCY INTERFERENCE.  SIGNAL INTERFERENCE
          GENERATED AT OR NEAR A RECEIVED WAVELENGTH.  THE FCC
          ESTABLISHES RFI STANDARDS TO REDUCE RFI.

  RFI:
          REQUEST FOR INFORMATION.  GENERAL NOTIFICATION OF AN
          INTENDED PURCHASE OF COMMUNICATIONS OR COMPUTER EQUIPMENT
          SENT TO POTENTIAL SUPPLIERS TO  DETERMINE INTEREST AND
          SOLICIT PRODUCT MATERIALS.

  RFP:
          REQUEST FOR PROPOSAL.  FOLLOW-UP TO RFI, SENT TO INTERESTED
          VENDORS TO SOLICIT A CONFIGURATION PROPOSAL, WITH PRICES,
          THAT MEETS A USER'S REQUIREMENTS.

  RGB:
          RED, GREEN, BLUE MONITOR.  A COLOR DISPLAY SCREEN FOR
          COMPUTERS.

  ROM:
          READ-ONLY MEMORY. HIGH SPEED INTERNAL MEMORY CONTAINING
          PERMANENTLY RECORDED INFORMATION.

  RS232:
          A LEVEL 1 STANDARD PROMULGATED BY EIA FOR THE PHYSICAL
          INTERFACE BETWEEN DATA COMMUNICATIONS EQUIPMENT (DCE) AND
          DATA TERMINAL EQUIPMENT (DTE)

  RS422:
          A LEVEL 1 STANDARD PROMULGATED BY EIA FOR THE PHSICAL
          INTERFACE BETWEEN DATA COMMUNICATIONS EQUIPMENT (DCE) AND
          DATA TERMINAL EQUIPMENT (DTE).

  RS449:
          A LEVEL 1 STANDARD PROMULGATED BY EIA FOR THE PHYSICAL
          INTERFACE BETWEEN DATA COMMUNICATIONS EQUIPMENT (DCE) AND
          DATA TERMINAL EQUIPMENT (DTE).  EIA SPECIFICATION FOR
          GENERAL PURPOSE, 37-POSITION AND 9-POSITION INTERFACE FOR
          DTE AND DCE EMPLOYING SERIAL BINARY DATA INTERCHANGE.

  SAA:
          SYSTEMS APPLICATION ARCHITECTURE.  IBM'S ANNOUNCED FRAMEWORK
          FOR ALLOWING DEVELOPMENT OF CONSISTENT APPLICATIONS ACROSS
          SIX SOFTWARE ENVIRONMENTS (TSO/F, CICS/MVS, IMS/ESA/TM,
          VM/CMS, OS400, AND OS/2 EXTENDED EDITION) RUNNING ON THREE
          HARDWARE COMPUTING PLATFORMS (SYSTEMS 370 ESA, OS/400, AND
          PS/2).

  SDLC:
          IBM'S VERSION OF A BIT ORIENTED DATA LINK CONTROL PROTOCOL.

  SELECTING:
          IN THE BSC POLLED PROTOCOL, THE PROCESS OF INFORMING A
          PARTICULAR STATION THAT THE NEXT TRANSMISSION IS DIRECTED
          TO THAT STATION.

  SEMICONDUCTOR:
          A SUBSTANCE THAT CAN ACT AS A CONDUCTOR OR INSULATOR OF
          ELECTRICITY DEPENDING ON ITS CHARGED STATE; IT ACTS AS AN
          ON/OFF SWITCH SIGNIFYING BINARY DIGITS (1'S AND O'S).

  SERIAL:
          SERIAL TRANSMISSION.  A METHOD OF TRANSMISSION IN WHICH EACH
          BIT OF INFORMATION IS SENT SEQUENTIALLY ON A SINGEL CHANNEL
          RATHER THAN SIMULTANEOUSLY AS IN PARALLEL TRANSMISSION.

  SERVER:
          A PROCESSOR THAT PROVIDES A SPECIFIC SERVICE TO THE NETWORK,
          E.G., A ROUTING SERVER CONNECTS NODES AND NETWORK OF LIKE
          ARCHITECTURES, A GATEWAY SERVER CONNECTS NODES AND NETWORKS
          OF DIFFERENT ARCHITECTURES, ETC.

  SHIELD PAIR:
          TWO INSULATED WIRES IN A CABLE WRAPPED WITH METALLIC BRAID
          OR FOIL TO PREVENT INTERFERENCE AND PROVIDE NOISE-FREE
          TRANSMISSION.

  SIMPLEX:
          SIMPLEX MODE.  OPERATION OF A CHANNEL IN ONE DIRECTION ONLY
          WITH NO CAPABILITY OF REVERSING.

  SIX BIT TRANSCODE:
          A SIX BIT CHARACTER CODE USERD PRIMARILY BY IBM EQUIPMENT.

  SMS:
          SHORT MESSAGE SERVICE DEFINED BY GSM FOR WIRELESS.

  SMTP:
          SIMPLE MAIL TRANSFER PROTOCOL.  SERVICE SPECIFICALLY FOR
          ELECTRONIC MAIL THAT FUNCTIONS AS A UNIFIED "POST OFFICE"
          FOR ADDRESSING MAIL TO ALL USERS ON ALL NODES OF BOTH WIDE
          AREA AND LOCAL NETWORKS.

  SNA:
          SYSTEMS NETWORK ARCHITECTURE.  IBM'S LAYERED TRANSMISSION
          PROTOCOL FOR DATA COMMUNICATIONS AMONG IBM COMPUTERS AND
          TERMINALS.

  SNA:
          SYSTEMS NETWORK ARCHITECTURE.  THE COMPUTER AND
          COMMUNICATIONS NETWORK ARCHITECTURE DEFINED BY IBM.  THE
          TOTAL DESCRIPTION OF THE LOGICAL STRUCTURE, FORMATS,
          PROTOCOLS, AND OPERATIONS SEQUENCES FOR TRANSMITTING
          INFORMATION UNITS THROUGH THE COMMUNICATION SYSTEM.

  SNA:
          SYSTEMS NETWORK ARCHITECTURE.  IBM'S STANDARDIZED
          RELATIONSHIP BETWEEN ITS VIRTUAL TELECOMMUNICATION
          ACCESS METHOD (VTAM) AND THE NETWORK CONTROL PROGRAM
          (NCP/VS).

  SOH:
          START OF HEADER.  A COMMUNICATION CONTROL CHARACTER USED TO
          IDENTIFY THE BEGINNING OF THE HEADER FIELD OF A MESSAGE
          BLOCK.

  SOP:
          STANDARD OPERATING PROCEDURE.

  SPACE:
          USUALLY EQUIVALENT TO A BINARY ZERO CONDITION.

  SSCP:
          SYSTEM SERVICES CONTOL POINT.  THE ADDRESSABLE UNIT IN AN
          SNA DOMAIN WHICH IS RESPONSIBLE FOR OVERALL CONTROL OF THE
          RESOURCES IN THAT DOMAIN.

  STAR:
          A NETWORK TOPOLOGY IN WHICH EACH STATION IS CONNECTED ONLY
          TO A CENTRAL STATION BY A POINT-TO-POINT LINK AND
          COMMUNICATES WITH ALL OTHER STATIONS THROUGH THE CENTRAL
          STATION.

  STARLAN:
          A LOCAL NETWORK DESIGN AND SPECIFICATION WITHIN IEEE 802.3
          STANDARDS SUBCOMMITTEE, CHARACTERIZED BY 1M BPS BASEBAND
          DATA TRANSMISSION OVER TWO-PAIR, TWISTED-PAIR WIRING.

  START BIT:
          IN ASYNCHRONOUS TRANSMISSION, THE BIT WHICH SYNCHRONIZES THE
          RECEIVER CLOCK TO THE RECEIVING DATA, DONE AT EACH RECEIVED
          CHARACTER.  THE START BIT IS ALWAYS A SPACE.

  START OF HEADER:
          A COMMUNICATION CONTROL CHARACTER USED TO IDENTIFY THE
          BEGINNING OF THE HEADER FIELD OF A MESSAGE BLOCK.

  START OF TEXT:
          A COMMUNICATION CONTROL CHARACTER WHICH PRECEDES THE TEXT
          IN THE MESSAGE BLOCK.

  STATION:
          THE DATA TERMINAL EQUIPMENT FROM OR TO WHICH MESSAGES ARE
          TRANSMITTED ON A DATA LINK.

  STATISTICAL MULTIPLEXING:
          A SYSTEM OF TIME DIVISION MULTIPLEXING ON WHICH ONLY THE
          LIVE DATA ON EACH LOW SPEED CHANNEL IS ALLOCATED TO TIME
          SLOTS ON THE HIGH SPEED CHANNEL BETWEEN MULTIPLEXERS.

  STATMUX:
          STATISTICAL MULTIPLEXING.  A SYSTEM OF TIME DIVISION
          MULTIPLEXING ON WHICH ONLY THE LIVE DATA ON EACH LOW SPEED
          CHANNEL IS ALLOCATED TO TIME SLOTS ON THE HIGH SPEED
          CHANNEL BETWEEN MULTIPLEXERS.

  STOP BIT:
          IN ASYCHRONOUS TRANSMISSION THE BIT/S WHICH TERMINATE THE
          CHARACTER FRAME, ALWAYS A MARK, SO THAT A START BIT WILL BE
          CLEARLY RECOGNIZED ON THE MARK-TO-SPACE TRANSITION.

  STORE AND FORWARD:
          THE PROCESS OF MESSAGE HANDLING USED IN MESSAGE SWITCHING
          SYSTEMS IN WHICH MESSAGES ARE TEMPORARILY STORED AND THEN
          FORWARDED.

  STX:
          START OF TEXT.  A COMMUNICATION CONTROL CHARACTER WHICH
          PRECEDES THE TEXT IN THE MESSAGE BLOCK.

  SUPERSCRIPT:
          A SYMBOL THAT APPEARS ABOVE THE CHARACTER BASE LINE.

  SWITCHED LINE:
          A COMMUNICATION LINK FOR WHICH THE PHYSICAL PATH MAY VARY
          WITH EACH USAGE, E.G., THE DIAL-UP TELEPHONE NETWORK.

  SYNCHRONOUS:
          SYNCHRONOUS TRANSMISSION.  TRANSMISSION IN WHICH THE DATA
          CHARACTERS AND BITS ARE TRANSMITTED AT A FIXED RATE WITH
          THE TRANSMITTER AND RECEIVER SYNCHRONIZED.

  SYNCHRONOUS DATA LINK CONTROL:
          IBM'S VERSION OF A BIT ORIENTED DATA LINK CONTROL PROTOCOL.

  SYSGEN:
          SYSTEM GENERATION.  THE PROCESS OF USING A MASTER CONTROL
          PROGRAM TO ASSEMBLE AND LINK ALL THE PARTS THAT CONSTITUTE
          ANOTHER OPERATING SYSTEM.

  SYSTEMS NETWORK ARCHITECTURE:
          IBM'S LAYERED TRANSMISSION PROTOCOL FOR DATA COMMUNICATIONS
          AMONG IBM COMPUTERS AND TERMINALS.

  SYSTEMS NETWORK ARCHITECTURE:
          THE COMMPUTER AND COMMUNICATIONS NETWORK ARCHITECTURE
          DEFINED BY IBM.  THE DTOAL DESCRIPTION OF THE LOGICAL
          STRUCTURE, FORMATS, PROTOCOLS, AND OPERATIONAL SEQUENCES FOR
          TRANSMITTING INFORMATION UNITS THROUGH THE COMMUNICATION
          SYSTEM.

  T1:
          A DIGITAL CARRIER FACILITY USED TO TRANSMIT A DS1 FORMATED
          DIGITAL SIGNAL AT 1.544M BPS; THE EQUIVALENT OF 24 VOICE
          CHANNELS.  THE EUROPEAN EQUIVALENT TRANSMITS A 2.048M BPS.

  T1C:
          A DIGITAL CARRIER FACILITY USED TO TRANSMIT A DS1C FORMATTED
          DIGITAL SIGNAL AT 3.153M BPS;  THE EQUIVALENT OF 48 VOICE
          CHANNELS.

  T2:
          A DIGITAL CARRIER FACILITY USED TO TRANSMIT A DS2 FORMATED
          DIGITAL CARRIER SIGNAL AT 6.312M BPS; THE EQUIVALENT OF
          94 VOICE CHANNELS.

  T3:
          A DIGITAL CARRIER FACILITY USED TO TRANSMIT A DS3 FORMATTED
          DIGITAL SIGNAL AT 44M BPS;  THE EQUIVALENT OF 672 VOICE
          CHANNELS.

  T4:
          A DIGITAL CARRIER FACILITY USED TO TRANSMIT A DS4 FORMATTED
          DIGITAL CARRIER SIGNAL AT 273M BPS; THE EQUIVALENT OF 4,032
          VOICE CHANNELS.

  TCAM:
          TELECOMMUNICATIONS ACCESS METHOD.  AN IBM MACRO LANGUAGE FOR
          CREATING COMMUNICATION APPLICATIONS PROGRAMS AND MESSAGE
          CONTROL.

  TCP/IP:
          TRANSMISSION CONTROL PROTOCOL/INTERNET PROTOCOL.  ENSURES
          PACKETS OF DATA ARE DELIVERED TO THEIR DESTINATIONS IN THE
          SEQUENCE IN WHICH THEY WERE TRANSMITTED.

  TDM:
          TIME DIVISION MULTIPLEXING.  A SYSTEM OF MULTIPLEXING IN
          WHICH CHANNELS ARE ESTABLISHED BY CONNECTING TERMINALS ONE
          AT A TIME AT REGULAR INTERVALS BY MEANS OF AN AUTOMATIC
          DISTRIBUTION.

  TELNET:
          TELETYPE NETWORK.  PROVIDES A VIRTUAL TERMINAL CAPABILITY
          FOR ACCESSING REMOTE SYSTEMS AS A TERMINAL.

  TEXT:
          A SEQUENCE OF CHARACTERS FORMING PART OF A TRANSMISSION
          WHICH IS SENT FROM THE DATA SOURCE TO THE DATA SINK, AND
          CONTAINS THE INFORMATIO TO BE CONVEYED.

  TIME DIVISION MULTIPLEXING:
          A SYSTEM OF MULTIPLEXING IN WHICH CHANNELS ARE ESTABLISHED
          BY CONNECTING TERMINALS ONE AT A TIME AT REGULAR INTERVALS
          BY MEANS OF AN AUTOMATIC DISTRIBUTION.

  TOKEN BUS:
          A LOCAL NETWORK ACCESS MECHANISM AND TOPOLOGY IN WHICH ALL
          STATIONS ACTIVELY ATTACHED TO THE BUS LISTEN FOR A BROADCAST
          TOKEN OR SUPERVISORY FRAME.  STATIONS WISHING TO TRANSMIT
          MUST RECEIVE THE TOKEN BEFORE DOING SO; HOWEVER, THE NEXT
          PHYSICAL STATION TO TRANSMIT IS NOT NECESSARILY THE NEXT
          PHYSICAL STATION ON THE BUS.  BUS ACCESS IS CONTROLLED BY
          PREASSIGNED PRIORITY ALGORITHMS.

  TOKEN PASSING:
          A LOCAL AREA NETWORK ACCESS TECHNIQUE IN WHICH PARTICIPATING
          STATIONS CIRCULATE A SPECIAL BIT PATTERN THAT GRANTS ACCESS
          TO THE COMMUNICATIONS PATHWAY TO ANY STATION THAT HOLDS THE
          SEQUENCE; OFTEN USED IN NETWORKS WITH A RING TOPOLOGY.

  TOKEN RING:
          A LOCAL NETWORK ACCESS MECHANISM AND TOPOLOGY IN WHICH A
          SUPERVISORY FRAME OR TOKEN IS PASSED FROM STATION TO STATION
          IN SEQUENTIAL ORDER.  STATIONS WISHING TO GAIN ACCESS TO THE
          NETWORK MUST WAIT FOR THE TOKEN TO ARRIVE BEFORE
          TRANSMITTING DATA.  IN A TOKEN RING, THE NEXT LOGICAL
          STATION IS ALSO THE NEXT PHYSICAL STATION ON THE RING.

  TOP:
          TECHNICAL OFFICE PROTOCOLS DEVELOPED BY BOEING.

  TRANSPARENT MODE:
          TRANSMISSION OF BINARY DATA WITH THE RECOGNITION OF MOST
          CONTROL CHARACTERS SUPRESSED.  IN BINARY SYNCHRONOUS
          COMMUNICATIONS, ENTRY TO AND EXIT FROM THE TRANSPARENT MODE
          IS INDICATED BY THE SEQUENCES DLE-STX AND DLE-ETX (OR
          DLE-ETC, DLE-ITB, ENQ).

  TRUNK:
          A SINGEL CIRCUIT BETWEEN TWO POINTS, BOTH OF WHICH ARE
          SWITCHING CENTERS OR INDIVIDUAL DISTRIBUTION POINTS.

  TWO-WIRE:
          TWO-WIRE CIRCUIT.  CIRCUIT FORMED BY TWO CONDUCTORS
          INSULATED FROM EACH OTHER THAT CAN BE USED AS A ONE-WAY
          TRANSMISSION PATH, A HALF-DUPLEX PATH, OR DUPLEX PATH.

  UDLC:
          UNIVERSAL DATA LINK CONTROL.  A BIT-ORIENTED PROTOCOL BASED
          ON HDLC DEVELOPED BY SPERRY UNIVAC (NOW UNISYS.)

  UHF:
          ULTRA HIGH FREQUENCY.  PORTION OF THE ELECTROMAGNETIC
          SPECTRUM RANGING FROM ABOUT 300 MHZ TO ABOUT 3 GHZ.  THE
          FREQUENCY BAN INCLUDES TELEVISION AND CELLULAR RADIO
          FREQUENCIES.

  UNIX:
          A MULTIUSER OPERATING SYSTEM DEVELOPED BY BELL LABORATORIES.

  UPLINK:
          THE PORTION OF A SATELLITE CIRCUIT EXTENDING FROM AN EARTH
          STATION TO THE SATELLITE.

  UPS:
          UNINTERRUPTIBLE POWER SUPPLY.  USUALLY INCLUDES AN INVERTER,
          DRAWING ITS POWER FROM BATTERIES, WHICH GENERATES AN
          EXTREMELY "WELL-BEHAVED" AC POWER SIGNAL FOR A PBX OR OTHER
          EQUIPMENT.  THE UPS COST IS RELATED TO THE AMOUNT OF POWER
          NEEDED AND THE LENGHT OF TIME IT MUST OPERATE DURING A
          FAILURE.  IF A PARTICULARLY HEAVY DEMAND IS ANTICIPATED, THE
          SYSTEM CAN BE COUPLED WITH AN AUXILIARY GENERATOR THAT IS
          STARTED WHEN COMMERCIAL POWER IS INTERRUPTED.

  V.21:
          CCITT RECOMMENDATION.  300 BPS MODEM STANDARDIZED FOR USE IN
          GENERAL SWITCHED TELEPHONE NETWORK.

  V.22:
          CCITT RECOMMENDATION.  STANDARDIZATON OF MODULATION RATES
          AND DATA-SIGNALING RATES FOR SYNCHRONOUS DATA TRANSMISSON
          IN THE GENERAL SWITCHED TELEPHONE NETWORK.

  V.29:
          CCITT RECOMMENDATION.  9600 BIT/S MODEM STANDARDIZED FOR USE
          ON POINT-TO-POINT 4 WIRE LEASED TELEPHONE CIRCUITS.

  VAN:
          VALUE-ADDED NETWORK.  A PUBLIC DATA COMMUNICATIONS NETWORK
          THAT PROVIDES BASIC TRANSMISSION FACILITIES (GENERALLY
          LEASED BY THE VAN VENDOR FROM A COMMON CARRIER) PLUS
          ADDITIONAL, "ENHANCED" SERVICES SUCH AS COMPUTERIZED
          SWITCHING, TEMPORARY DATA STORAGE, PROTOCOL CONVERSION,
          ERROR DETECTION AND CORRECTION, ELECTRONIC MAIL SERVICE,
          ETC.

  VDT:
          1) VIDEO DISPLAY TERMINAL.  2) VISUAL DISPLAY TERMINAL.

  VHF:
          VERY HIGH FREQUENCY.  PORTION OF THE ELECTROMAGNETIC
          SPECTRUM WITH FREQUENCIES BETWEEN ABOUT 30 MHZ AND 300
          MHZ.  OPERATING BAND FOR RADIO AND TELEVISON CHANNELS.

  VIRTUAL CIRCUIT:
          A CONNECTION BETWEEN A SOURCE AND A SINK IN A PACKET
          SWITCHING NETWORK THAT MAY BE REALIZED BY DIFFERENT CIRCUIT
          CONFIGURATIONS DURING TRANSMISSION OF A MESSAGE.  ALSO
          CALLED LOGICAL CIRCUIT.

  VLSI:
          VERY LARGE SCALE INTERGRATION.

  VOICE GRADE CHANNEL:
          A CHANNEL USED FOR SPEECH TRANSMISSION USUALLY WITH AN AUDIO
          FREQUENCY RANGE OF 300-3300 HERTZ.  CALLED TYPE 3002 CIRCUIT
          BY AT&T.

  VOLATILE STORAGE:
          MEMORY THAT LOSES ITS CONTENTS WHEN ELECTRICAL POWER IS
          REMOVED.

  VSAT:
          VERY SMALL APERTURE TERMINAL.  AN EARTH STATION WITH A SMALL
          ANTENNA, USUALLY 6 METERS OR LESS. VSAT'S ARE TYPICALLY USED
          IN POINT-TO-MULTIPOINT DATA NETWORKS.

  VTAM:
          VIRTUAL TELECOMMUNICATIONS ACCESS METHOD.  AN IBM
          COMMUNICATIONS I/O CONTROL PROGRAMMING SOFTWARE THAT USES
          VIRTUAL TECHNIQUES.

  WATS:
          WIDE AREA TELEPHONE SERVICE.  A SERVICE PROVIDED BY
          TELEPHONE COMPANIES IN THE UNITED STATES THAT PERMITS A
          CUSTOMER TO MAKE CALLS TO OR FROM TELEPHONES IN SPECIFIC
          ZONES, WITH A DISCOUNTED MONTHLY CHARGE BASED UPON CALL
          VOLUME.

  WIDE AREA TELEPHONE SERVICE:
          A SERVICE PROVIDED BY TELEPHONE COMPANIES IN THE UNITED
          STATES THAT PERMITS A CUSTOMER TO MAKE CALLS TO OR FROM
          TELEPHONES IN SPECIFIC ZONES, WITH A DISCOUNTED MONTHLY
          CHARGE BASED UPON CALL VOLUME.

  WINDOW:
          THE MECHANISM USED FOR FLOW CONTROL IN A PACKET SWITCHED
          NETWORK TO PREVENT OVERLOAD IN THE NETWORK.  THE WINDOW SIZE
          INDICATES THE NUMBER OF PACKETS A USER CAN HAVE OUTSTANDING
          (UNACKNOWLEDGED) IN A NETWORK AT ANY GIVEN TIME.

  X.21:
          INTERFACE BETWEEN DATA TERMINAL EQUIPMNET (DTE) AND DATA
          CIRCUIT-TERMINATING EQUIPMENT (DCE) FOR SYNCHRONOUS
          OPERATION ON PUBLIC DATA NETWORKS.  SPECIFIES PROTOCOLS FOR
          ALL THREE LOWEST LAYERS OF OSI.  EFFICIENT TRANSFER OF DATA
          BIT STREAMS (UNBLOCKED) BETWEEN THE DTE AND DCE.  ONLY USED
          FOR LINK ESTABLISHMEN/DISESTABLISHMENT AND OTHER CONNECTION
          CONTROL FUNCTIONS.  APPLICABLE TO BOTH LEASED LINES AND
          CIRCUIT SWITCHING.

  X.25:
          INTERFACE BETWEEN DATA TERMINAL EQUIPMENT (DTE) AND DATA
          CIRCUIT-TERMINATING EQUIPMENT (DCE) FOR TERMINALS OPERATING
          IN THE PACKET MODE ON PUBLIC DATA NETWORKS.  JOINTLY
          PRODUCED BY CCITT AND ISO.  FOR AN INTERFACE ONLY.

  X.28:
          DEFINES THE TERMINAL-PAD INTERFACE.  DTE/DCE INTERFACE FOR A
          START-STOP MODE DATA TERMINAL EQUIPMENT ACCESSING THE PACKET
          ASSEMBLY/DISASSEMBLY FACILITY ON A PUBLIC DATA NETWORK
          SITUATED IN THE SAME COUNTRY.

  X.29:
          DEFINES THE PAD-COMPUTER INTERFACE.  PROCEDURES FOR EXCHANGE
          OF CONTROL INFORMATION AND USER DATA BETWEEN A PACKET
          ASSEMBLY/DISASEMBLY FACILITY (PAD) AND A PACKET-MODE DTE OR
          ANOTHER PAD.

  X.3:
          DEFINES THE PAD PARAMETES AND OPERATION.  PACKET ASSEMBLY/
          DISASSEMBLY FACILITY IN A PUBLIC DATA NETWORK.

  X.400:
          A STANDARD FOR ELECTRONIC MAIL EXCHANGE; DEVELOPED BY THE
          CCITT.

  X.75:
          CCITT RECOMMENDATION.  TERMINAL AND TRANSIT CALL CONTROL
          PROCEDURE AND DATA TRANSFER SYSTEM BETWEEN PACKET SWITCHED
          PUBLIC DATA NETWORKS.

  XENIX:
          A MULTIUSER OPERATING SYSTEM DEVELOPED BY MICROSOFT, INC.;
          A SUBSET OF UNIX.

  XMODEM:
          AN EIGHT BIT, PUBLIC DOMAIN ERROR CHECKING PROTOCOL
          DEVELOPED IN THE LATE 1970'S BY WARD CHRISTENSEN.  THE FILE
          TRANSFER PROTOCOL USES A 128-BYTE DATA BLOCK AND CRC OR
          CHECKSUM ERROR CHECKING METHODS.

  YMODEM:
          A FILE TRANSFER PROTOCOL BASED ON CRC XMODEM THAT WAS
          DEVELOPED BY CHUCK FORSBERG.  YMODEM HAS A 1024-BYTE
          PACKET SIZE.

  ZERO SUPPRESSON:
          THE ELIMINATION OF NONSIGNIFICANT 0'S IN A NUMERAL.