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TUCoPS :: Phreaking Technical System Info :: mcitg4.txt

MCI Telecom Glossary Pt.4

                                 _  _        _______
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                                |_||_|etal / /hop
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                                Proudly Presents

                      The MCI Telecommunications Glossary

                            Part I Volume IV (T - W)

                      Typed and edited by Knight Lightning


                                     - T -

T-CARRIER                              A time-division, pulse modulation, voice
                                       carrier used on exchange cable to
                                       provide short-haul trunks.

TAIL END HOP OFF (TEHO)                In a private network, a call which is
                                       carried over a flat rate facilities
                                       (Intermachine Trunks or IMT) to the
                                       closest switch node to the destination
                                       of the call, and then connected into the
                                       public network as a local call.

TANDEM                                 A switching arrangement in which the
                                       trunk from the calling office is
                                       connected to a trunk to the called
                                       office through an intermediate point.

TANDEM SWITCHING SYSTEM                Synonym: Tandem Tie Trunk Network.

TANDEM TIE TRUNK NETWORK (TTTN)        A serving arrangement which permits
                                       sequential connection of tie trunks
                                       between PBX/CENTREX locations by
                                       utilizing tandem operation.

TANDEM TRUNKING                        Trunks which connects two or more
                                       switches together.

TARIFF                                 The published rates, regulations, and
                                       descriptions governing the provisions of
                                       communications service.

TELCO                                  Local telephone company.

TELECOMMUNICATIONS                     The transmission of voice and/or data
                                       through a medium by means of electrical
                                       impulses and includes all aspects of
                                       transmitting information.

TELEGRAPH                              A system employing the interruption of,
                                       or change in, the polarity of DC current
                                       signaling to convey coded information.

TELEPHONE                              A device which converts acoustical
                                       (sound) energy into electrical energy
                                       for transmission to a distant point.

TELETYPEWRITER                         A machine used to transmit and/or
                                       receive communications on printed page
                                       and/or tape.

TERMINAL                               (1) The device used at a subscriber's
                                       location for purposes of communicating,
                                       such as the telephone instrument,
                                       teleprinter, computer terminal, etc.,
                                       (2) The "end point" or extremity" such
                                       as Terminal Pole of an open wire line,
                                       or Terminal Office representing the
                                       final central office in a switching
                                       network where the subscriber's call
                                       originates or terminates.

TERMINAL EQUIPMENT                     Devices, apparatus, and their associated
                                       interfaces used to forward information
                                       to a local customer or a distant

TERMINATION                            (1) An item that is connected to the
                                       terminal of a circuit or equipment.
                                       (2) An impendance connected to the end
                                       of a circuit being tested.

TIE-LINE                               A private line connecting two PBXs.

TIME DIVISION MULTIPLEXING (TDM)       Equipment which enables the transmitting
                                       of a number of signals over a single
                                       path by  transmitting them sequentially
                                       at different instants of time.

TOLL CALL                              Any call to a point outside the local
                                       service area.

TOLL CENTER                            (1) A central office where  operators
                                       (human or mechanical) are present to
                                       assist in completing incoming toll
                                       calls. (2) A center for the switching of
                                       toll calls.

TOLL PLANT                             The facilities that connect toll offices
                                       throughout the country.

TOLL RESTRICTION                       A restriction in outgoing trunks which
                                       counts the first three digits dialed and
                                       diverts calls to forbidden codes either
                                       to a busy tone, to the operator, or to a
                                       recorded announcement.

TOUCH-TONE ADAPTOR                     A device that can be connected to a
                                       rotary dial telephone to allow for DTMF

TRAFFIC                                Calls being sent and received over a
                                       communications network.

TRAFFIC MEASUREMENT AND RECORDING      A computer generated report showing usage
SYSTEMS (TMRS)                         usage information of telephone systems.
                                       Usually this includes trunk utilization,
                                       outages, queueing time, and the need for
                                       additional common equipment.

TRAFFIC SERVICE POSITION SYSTEM        A toll switchboard position configured
(TSPS)                                 as a push button console.

TRANSMISSION                           The electrical transfer of a signal,
                                       mesage or other forms of data from one
                                       location to another without unacceptable
                                       loss of information content due to
                                       attenuation, distortion, or noise.

TRANSMISSION LEVEL                     The level of power of a signal normally
                                       1,000 Hz, which should be measured at a
                                       particular reference point.

TRANSMISSION SPEED                     Number of pulses or bits transmitted in
                                       a given period of time, usually
                                       expressed as Bits Per Second (BPS) or
                                       Words Per Minute (WPM).

TRUNK                                  A single circuit between two points both
                                       of which are switching centers and/or
                                       individual distribution points.

TRUNK GROUP                            An arrangement of communications
                                       channels into an identical group.

TRUNK TYPE (TT)                        Trunks that use the same type of
                                       equipment going to to the same
                                       terminating location.

TRUNK UTILIZATION REPORT (TUR)         A computer printout detailing the
                                       traffic use of a trunk.

TWO-WIRE CIRCUIT                       1. A channel for tranamitting data in
                                       one direction at a time. 2. A short
                                       distance channel using a single
                                       send/receive pathway, usually 2 copper
                                       wires, connecting a telephone to a

TELETYPEWRITER EXCHANGE SERVICE        A service whereby a customer's leased
(TWX)                                  teletypewriter is connected to a "TWX"
                                       switchboard and from there connected
                                       over regular toll circuits to
                                       teletypewriter of any U.S. customer who
                                       subscribes to a similar service.

                                     - U -

UNIFORM CALL DISTRIBUTOR (UCD)         A device located at the telephone office
                                       or in a PABX which distributes incoming
                                       calls evenly among individuals.

UNIFORM SERVICE ORDER CODE (USOC)      The information in coded form for
                                       billing purposes by the local telephone
                                       company pertaining to information on
                                       service orders and service equipment

                                     - V -

VALUE-ADDED NETWORK SERVICE (VANS)     A data transmission network which routes
                                       messages according to available paths,
                                       assures that the message will be
                                       received as it was sent, provides for
                                       user security, high speed transmission,
                                       and conferencing among terminals.

VIA NET LOSS (VNL)                     The lowest loss in dB at which a trunk
                                       facility can be operated considering
                                       limitations of echo, crosstalk, noise,
                                       and singing.

VOICE CONNECTING ARRANGEMENT           An interface arrangement provided by the
                                       telephone company to accomodate the
                                       connections of non-carrier provided
                                       voice terminal equipment to the public
                                       switched telephone network.

VOICE FREQUENCY (VF)                   Any of the frequencies in the band
                                       300-3,400 Hz which must be transmitted
                                       to reproduce the voice with reasonable

VOICE GRADE                            An access line  suitable for voice,
                                       low-speed data, facsimile, or telegraph
                                       service. Generally, it has a frequency
                                       range of about 300-3000 Hz.

VOICE GRADE FACILITY (VGF)             A circuit designed to DDD network
                                       standards which is suitable for voice,
                                       low-speed data, facsimile, or telegraph

                                     - W -

WIDE AREA TELECOMMUNICATIONS          A special direct distance dialing (toll)
SERVICE (WATS)                        service whereby a subscriber installs a
                                      dedicated line arranged for either
                                      inward or outward calls (not both)
                                      between the customer's premises and a
                                      specific gepgraphic area.

WIDEBAND                              A term applied to facilities or circuits
                                      where bandwidths are greater than that
                                      required for one voice channel.

WIRE CENTER                           The physical structure that house one or
                                      more channel office switching systems.


This concludes Part I Volume IV of the MCI Telecommunications Glossary. Look
for more G-philes on MCI by Knight Lightning coming soon to Metal Shop.

                      This has been a 2600 Club production

                              Thanx to Taran King

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