E
`
`Updated 151h
`
`Expanded
`Edition
`
`Bright House Networks
`- Ex. 1032, Page 1
`
`

`
`NEWTON's TELECOM DICTIONARY
`
`Copyright© 1999 Harry Newton
`email: Harry@HarryNewton.com
`personal web site: www.HarryNewton.com
`
`All rights reserved under International and Pan-American Copyright conventions, including the right
`to reproduce this book or portions thereof in any form whatsoever.
`
`Published in the United States by
`Miller Freeman, Inc.
`Tenth floor
`12 West 21 Street
`New York, NY 10010
`212-691-8215 Fax 212-691-1191
`1-800-999-0345 and 1-800-LIBRARY
`
`ISBN Number 1-57820-031-8
`
`August, 1999
`
`For individual orders, and for information on special discounts for quantity orders, please contact:
`Telecom Books
`6600 Silacci Way
`Gilroy, CA 95020
`Tei:800-LIBRARY or 408-848-3854
`Fax:408-848-5784
`Email:telecom@rushorder.com
`
`Distributed to the book trade in the U.S. and Canada by
`Publishers Group West
`1700 Fourth St., Berkeley, CA 94710
`
`Fifteenth Edition, Expanded and Updated
`Matt Kelsey, Publisher
`Christine Kern, Manager
`
`Manufactured in the United States of America
`
`Bright House Networks
`- Ex. 1032, Page 2
`
`

`
`NEWTON'S TELECOM DICTIONARY
`
`(«:~II Control Sign«:~! Any one of the entire set of interactive
`signals necessary to establish, maintain, and release a call.
`Call D«:~ta Gail data refers to any data about a phone call
`that is passed by a switch to an attached computer telephony
`system. Call data is usually used by the computer telephony
`application to process the call more intelligently. Call data
`may be passed In-Band, over the same physical or logical link
`as the call- usually via tones, or Out-Of-Band, over a sep(cid:173)
`usually a serial link. Call data may also be
`arate link
`passed as part of the data designed to control telephone net(cid:173)
`works, such as SS7 (Signaling System 7) links. In addition to
`information about the call, status about the call and even con(cid:173)
`trol over the call, can be available as part of the call data link
`services. Call data almost always includes what number
`dialed the call (ANI) and/or what number called (DNIS). More
`complex call data links used for "PBX integration" may also
`indicate why the call was presented (such as forwarded on
`busy), tell what trunk the call is coming in on, or to pass mes(cid:173)
`sage waiting on or off indications, and other functions. Full
`blown computer telephony links, such as are now being
`offered by many switching vendors, enhance the call data
`path, providing additional status information about calls and
`can even provide a level of call control to the attached com(cid:173)
`puter telephony system. The above definition courtesy of
`Steve Gladstone, author of a great book called Testing
`Computer Telephony Systems, available from 212-691-8215.
`Call l>ei«!ly The delay encountered when a call reaches busy
`switching equipment. In normal POTS telephone service, the
`delay is considered OK if no more than one and a half percent
`of the calls are delayed by three seconds during the busy hour.
`l>ehuil Recording CDR. A feature of a telephone
`C€111
`system whicll allows the system to collect and record infor(cid:173)
`who
`incoming phone calls -
`mation on outgoing and
`made/received them, where they went/where they came from,
`what time of day they happened, how long they took, etc.
`Sometimes the data is collected by the phone system; some(cid:173)
`times it is pumped out of the phone system as the calls are
`made. Which ever way, the information must be recorded
`dumped right into a printer or into a PC with
`elsewhere -
`call accounting software. See also Call Accounting System.
`C~ll Diverter 1. A device which when connected to a called
`telephone number intercepts calls to that number and con(cid:173)
`nects them to a telephone operator or prerecorded message.
`2. An ancillary device which is connected to a telephone line.
`The device will, when the called telephone rings, initiate a
`telephone call on another line to a different telephone number.
`The calling party may or may not be aware that his call has
`been diverted to another telephone.
`Cedi l>ure~~tion The time from when the call is actually
`begun (i.e answered) to the instant either party hangs up. Call
`Duration is an important concept for traffic engineering.
`C«~IIIEstlllbiishment The process by which a call connec(cid:173)
`tion is created.
`Cc!lll forward Busy When your phone is busy, an incom(cid:173)
`ing call is transferred to another number. That number might
`be one appearing on your phone system. It might be one at
`your home in the same city. It could even be in another city.
`Call Forward Busy can perform the same as Rollover Lines. I
`use Call Forward Busy to move calls from the first line of my
`residence to my second line, because my local phone com(cid:173)
`pany charges too much for Rollover Lines. (Don't ask why.
`They don't know either.) You can get Call Forward Busy from
`central offices, as well as PBXs and some key systems. See
`also Rollover Lines.
`
`Call Forwarding A service available in many central
`and a feature of many PBXs and some hybrid PBX/key
`which allows an incoming call to be sent elsewhere.
`many variations on call forwarding: Call forwarding bus
`forwarding don't answer. Call forwarding all calls, etc.
`Call forward is a useful feature. For example, you're
`a meeting but you're expecting an important call. Pick
`phone, punch in some digits and all your calls will go
`new number- perhaps the phone outside the meeting
`The big disadvantage is that many people return to
`offices but forget they forwarded their calls elsewhere
`result, they usually miss a whole bunch of important'
`Some electronic phones now have a reminder light or
`sage on them saying "all calls are being forwarded."
`people program their PBXs to cancel all call forwards at
`and at midnight every day. This makes sense.
`Call forwarding is used to send calls to voice mail
`For example, tell your PBX that if your phone isn't
`in four rings, send that call to your voice mail.
`If you are getting call forwarding service from a central
`in North America, the code to begin call forwarding is
`the number you want to be forwarded to. To cancel it
`'
`punch in 73#.
`Call Frame Harris' PBX to computer link. Harris'
`for linking its PBX to an external computer and havi
`computer control the movement of calls within a Harris
`See also Open Application Interface.
`Call Guide A paper or screen "cheat sheet" that
`bullet points or actual copy for call center agents to
`they are on the telephone making marketing calls.
`vide responses to commonly asked questions or 0~1·, N"V••••w
`i
`the most effective way. Call guides are excellent
`as well as monitoring aids for coaches. See Call
`Routing.
`Call Guide Routing The process by which a call
`agent navigates through a call guide. The routing may
`ven from a computer-based menu or function key or
`ically by the computer system based on responses
`into a field.
`Call Handoff A cellular phone term. Call handoff
`when a wireless call is transferred to another cell site in
`conversation.
`Call Hold If you hang the phone up, you lose the caller. ·
`hold- a feature of most phone systems- allows
`"hold" the call, so the other person can't hear you.
`then return to the conversation by pushing a button on
`phone, typically the button flashing which shows which
`the person is sitting on hold. Call hold is useful when
`have someone on another line calling you.
`Call Identifier A network utility that is an
`assigned by the originating network for each
`partially established virtual call and, when used in
`tion with the calling DTE address, uniquely identifies the
`tual call over a period of time.
`Call In Absence Horn Alert A cellular car
`ture that sounds your car's horn when you are
`Call In Absence Indicator A cellular car phone
`that ensures that power to the cellular phone is not lost
`car's ignition is turned off.
`Call in Progress Override A cellular car phone
`that keeps power to the phone during a call even
`you've turned off the car's ignition.
`Call Letters Certain combinations of letters
`radio stations by the FCC. The group of letters assi
`
`134
`
`Bright House Networks
`- Ex. 1032, Page 3
`
`

`
`NEWTON'S TELECOM DICTIONARY
`a dozen or more T-1 s going to other central ollices where
`gested, the carrier will deliver the excess frames and bits. Any
`those channels may again be groomed with other circuits
`bits (in frames) above the Bc+Be will be discarded, usually at
`onto T-1 access lines at those sites). Also used to separate
`the point of network ingress-and not very gracefully, I might
`voice circuits from data circuits, and for combining then for
`add. For example, you might have a bunch of LANs at each
`delivery to service-specific switches in the CO.
`site. At each site, the LANs to a FRAD, in the form of a Frame
`Circuit Identification Code CIC. The part of CCS/SS7
`the public
`Relay-capable router. Each router connects to
`signaling message used to identify the circuit that is being
`Frame Relay network over a 56 Kbps circuit which terminates
`established between two signaling points (14 bits in the ISD(cid:173)
`in a 56 Kbps port on the carrier's closest FRND. As each PVC
`NUP).
`has a CIR of 32 Kbps, you be pretty sure that you can trans(cid:173)
`Circuit level Gateway A circuit level gateway ensures
`fer data at 32 Kbps, at least on the average over a period of
`that a trusted client and an untrusted host have no direct con(cid:173)
`time (e.g., a month). You also can burst above the CIR to the
`tact A circuit level gateway accepts a trusted client's requests
`level of the Be (Committed Burst Size), and with reasonable
`legitimacy of a
`for specific services and, after verifying the
`assurance that the data will get to the destination site. You can
`requested session, establishes a connection with an untrusted
`burst above the Be, although all bits in the Be (Excess Burst
`host After the connection is established, a circuit-level gateway
`Size) are subject to being marked DE (Discard Eligible). The
`copies packets back and forth-without further filtering them.
`DE bits wind up on the switch room floor in the event that the
`Circuit Mode 1. An AT&T term for the method of commu(cid:173)
`network is congested and the buffers in the network switches
`nications in which a fixed bandwidth circuit is established
`and routers overllow. You also can transmit above the total of
`from point to point through a network and held for the dura(cid:173)
`the Bc+Be, but those bits in those frames may wind up on the
`tion of a telephone call.
`switchroom floor at the ingress FRND. See also Committed
`2. An AIN term for a type of switching that causes a one-to(cid:173)
`Burst Size, Discard Eligible, Excess Burst Size, FRAD, Frame
`one correspondence between a call and a circuit That is, a
`Relay, FRND, Graceful Discard, Measurement Interval, Offered
`circuit or path is assigned for a call between each switching
`Load, Permanent Virtual Circuit, and Router.
`node, and the circuit or path is not shared with other calls.
`2. An ATM term. Committed Information Range: CIR is the
`Circuit Noise Level At any point in a transmission sys(cid:173)
`information transfer rate which a network offering frame relay
`tem, the ratio of the circuit noise at that point to some arbi(cid:173)
`services (FRS) is committed to transfer under normal condi(cid:173)
`trary amount of circuit noise chosen as a reference.
`tions. The rate is averaged over a minimum increment of time.
`Circuit Order Management System COMS. An
`Circuit The physical connection (or path) of channels, con(cid:173)
`automated processing system of MCI circuit- and service(cid:173)
`ductors and equipment between two given points through which
`related information. Processes hardwire service circuit orders
`an electric current may be established. Includes both sending
`from order entry through scheduling and completion. COMS
`and receiving capabilities. A circuit can also be a network of cir(cid:173)
`also provides circuit order data, hardwire customer data, and
`cuit elements, such as resistors, inductors, capacitors, semi(cid:173)
`in Finance,
`circuit inventory data to other MCI systems
`conductors, etc., that performs a specific function. A circuit can
`Engineering, and Operations.
`also be a closed path through which current can flow.
`Circuit Order Record COR. Report generated by the COR
`Circuit Board Same as a Printed Circuit Board, namely a
`indicating circuit installa(cid:173)
`Tracking System within NOBIS,
`board with microprocessors, transistors and other small elec(cid:173)
`tions, changes, and disconnects.
`tronics components. Such a board slides into a the slot in a tele(cid:173)
`Circuit Provisioning The telephone operating company
`phone system or personal computer. Also called a circuit card.
`process that somehow organizes to get you a trunk or other
`Circuit Breaker A special type of switch arranged to open
`special service circuit
`a circuit when overloaded, without injury to itself. A circuit
`Circuit Segregation Differentiating between services that
`breaker is basically a re-usable fuse. According to APC, a cir(cid:173)
`are maintained by separate technicians or departments. Can
`cuit breaker is a protective device that interrupts the flow of
`be accomplished through visual and/or mechanical means.
`current when the current exceeds a specified value. Circuit
`Circuit Switched Digital Capability CSDC. A ser(cid:173)
`breakers are calibrated when manufactured to a specific over(cid:173)
`regional Bell Operating
`implemented by some
`vice
`current value. Building or equipment wiring may overheat and
`Companies that offers users a 56 Kbps digital service on a
`become a fire hazard if excessive current is passed through
`user-switchable basis.
`such wiring. Circuit breakers or fuses are installed and coor(cid:173)
`to
`Circuit Switching Imagine making a phone call
`dinated with wiring by selecting the appropriate trip value so
`Grandma. You pick up the phone and dial Grandma. When
`that if equipment malfunction or user error causes too much
`you finish dialing, the various telephone company switches
`current to flow through a wire, the circuit breaker will trip to
`along the way pick a path for your call and move your call
`prevent the wire from overheating. For building wiring and
`along its way to Grandma. When Grandma answered, you and
`power distribution, the values of circuit panel breakers are
`she are now able to speak. Both of you now have the exclu(cid:173)
`specified in America by the National Electrical Code.
`sive and full use of the circuit that was set up between you.
`Circuit Card Same as a Circuit Board. See Circuit Board.
`You have that circuit until you (or she) hang up, at which time
`Circuit Emulation A connection over a virtual channel(cid:173)
`it goes idle until the system of switches grabs it for another
`based network providing service to the end user that is indistin(cid:173)
`"call." That call might be voice, data and video. Circuit
`guishable from a real, point-to-point, fixed bandwidth circuit
`switching has one big advantage: You get the full circuit tor
`Circuit Emulation Switching CES. Part of the ATM
`the full amount of the time you're using it And tor the most
`Forum's proposed Service Aspects and Applications (SAA)
`part, it's full duplex. Circuit switching has one big disadvan(cid:173)
`tage. Because you get the full circuit for the full amount of the
`standard.
`Circuit Grooming The practice of directing selected cir(cid:173)
`time, you pay for the privilege of tying up that circuit (no one
`cuit-switched DS-Os (64 kbit/s channels) from many T-1
`else can use it, even when there are pauses in your conversa(cid:173)
`trunks into a single T-1 (typical application is voice leased
`tion). Which means it's expensive.
`lines from a T-1 access line being 'groomed' in a DACS onto
`174
`
`Bright House Networks
`- Ex. 1032, Page 4
`
`

`
`NEWTON'S TELECOM DICTIONARY
`
`There are basically three types of switching- circuit, pack(cid:173)
`et and message:
`Circuit Switching, which I just explained, is like having your
`own railroad track for your conversation to travel on.lt's yours
`tor as long as you keep the connection open. No one else can
`use it. Once you hang up, the next caller gets to use that track.
`Virtually all voice telephone calls are circuit switched, though
`that won't be true in the future. All dial-up modem calls are
`circuit switched also.
`Packet Switching is like having your own railroad cars which
`you're sharing with other railroad cars on a railroad track. You
`slice the information you want to send so it fits into the cars,
`which join other cars to travel on the railroad track to the other
`end. You get pretty well as many railroad cars as you need.
`They will travel on different railroad tracks until they reach the
`station at the other end, where they'll be assembled in the
`order you sent them and then dropped off at your destination.
`Packet switching was originally created for sending data,
`since it's very efficient (and therefore cheap). One railroad
`track gets to carry a lot of "conversations." (In circuit switch(cid:173)
`ing, it only carries one conversation.) It does have the prob(cid:173)
`lem that it takes a little time to break up the data "conversa(cid:173)
`tions" into many packets, send them on their different ways
`and then reassemble them at the other end. But for data, that
`delay is barely noticeable. It can be noticeable, however, in a
`voice conversation, which is why packet switching hasn't
`IP
`until recently. (See
`been used much for voice -
`Telephony.) In packet switching, the addresses on your pack(cid:173)
`ets are read by the switches as they approach, and are
`switched down the tracks. The next packet is read to throw the
`switches to send that packet where it needs to go. The data
`conversation is sent in packets. Each packet can be sent along
`different tracks as they are open. The packets are assembled
`at the other end- typically in the last switching office before
`the packets reach the distant computer or distant user.
`Message Switching sends a message from one end to the
`other. But it's not interactive, as in packet or circuit switching.
`Of course, you can reply. But it's not like having a "conversa(cid:173)
`tion." In message switching, the message is typically received
`in one block, stored in one central place, then retrieved or
`sent in one clump to the other end. Message switching is like
`the post office, or like email. It can be slow. But it can also be
`cheap. Message can use a combination of circuit switching
`and packet switching to get its message through.
`Circuit, Four Wire A path in which four wires are present(cid:173)
`ed to the terminal equipment (phone or data), thus allowing for
`simultaneous transmission and reception. Two wires are used
`for transmission in one direction and two in the other direction.
`Circular Extension Network Permits two or more sin(cid:173)
`gle-line phones connected to a PBX, each with its own exten(cid:173)
`sion, to operate like a "square" key telephone system. An
`incoming call directed to any non-busy phone in the group
`will ring at all of the non-busy phones. The first extension to
`answer will be connected to the incoming call. At any time, a
`non-busy extension can make or receive calls.
`Circular Hunting When calling a phone, the switching
`system makes a complete search of all numbers within the
`hunting group, regardless of the location within that group of
`the called number. For example, the hunt group is 231, 232,
`233 and 234, the call is directed to 233. If it is busy, the equip(cid:173)
`ment will search 234, 231, and 232 to find a non-busy phone
`or line. Essentially it goes around the ring, remembering where
`1t last connected and then goes to the next line or phone in the
`circle. See also Hunt Group and Terminated Hunt Group.
`
`Circular Mil The measure of sectional area of a wire.
`Circular Polarization In electromagnetic wave propaga·
`lion, polarization such that the tip of the electric field vector
`describes a circle in any fixed plane intersecting, and normal
`to, the direction of propagation. The magnitude of the electric
`field vector is constant. A circularly polarized wave may be
`resolved into two linearly polarized waves in phase quadrature
`with their planes of polarization at right angles to each other.
`Circulator 1. In networking, a passive junction of three or
`more ports in which the ports can be accessed in such an
`order that when power is fed into any port it is transferred to
`the next port, the port counted as following the last in order.
`2. In radar, a device that switches the antenna alternately
`between the transmitter and receiver.
`Circumnaural A type of headphone that almost totally iso(cid:173)
`lates the listener from room sounds.
`CIS Contact Image Sensor. A type of scanner technology in
`which the photodetectors come in contact with the original
`document.
`CISC Complex Instruction Set Computing. PC Magazine
`defines CISC as a microprocessor architecture that favors
`robustness of the instruction set over the speed with which
`individual instructions are executed. The Intel 486 and
`Pentium are both examples of CISC microprocessors. See
`also RISC- Reduced Instruction Set Computing. See RISC.
`CISPR 22 This is a European Community standard specifying
`the limits of radio frequency emissions which appliances and
`other electrical equipment are allowed. The standard indicates
`the maxirnum allowable emissions either radiated or conduct(cid:173)
`ed via the power cord at various frequencies. Some countries
`still use the older VDE 0871 emission standards, which are
`nearly identical. In the USA, the FCC has a similar standard.
`CIT Computer Integrated Telephone is Digital Equipment
`Company's program, announced in October 1987, that pro(cid:173)
`vides a framework for functionally integrating voice and data in
`an applications environment so that the telephone and terminal
`on the desktop can be synchronized, the call arriving as the ter(cid:173)
`minal's screen on the caller arrives. CIT uses the DEC VAX line
`of computers. According to DEC, CIT supports both inbound
`and outbound telecommunications applications. In an inbound
`scenario, the application may recognize the caller's originating
`phone number through Automatic Number Identification (ANI)
`and/or the dialed number through Dialed Number Identification
`Service (DNIS), match the information to corresponding data
`base records and automatically deliver the call and the data to
`the call center agent. In an outbound application, dialing can be
`automated, increasing the number of connected calls. In either
`scenario, the telephone calls and associated data can be simul(cid:173)
`taneously transferred to alternate locations within an organiza(cid:173)
`tion, adding a new level of customer service to call center
`applications. Digital made its first CIT announcements at
`Telecom '87 in Geneva, Switzerland. The CIT product set, con(cid:173)
`sisting of client and server software implementing a variety of
`switch-to-computer link protocols, and providing a robust
`applications interface, was first shipped in 1989. The company
`announced its latest release, CIT Version 2.1, in January 1991.
`See also Open Application Interface.
`Citizens Band One of two bands used for low power radio
`transmissions in the United States- either 26.965 to 27.225
`megahertz or 462.55 to 469.95 megahertz. Citizens band
`radio is not allowed in many countries, even some civilized
`countries. In some countries they use different frequencies.
`CB radios, in the United States, are limited by FCC rule to four
`WATTS of power, which gives each CB radio a range of sev-
`
`175
`
`Bright House Networks
`- Ex. 1032, Page 5
`
`

`
`CTIONARY
`
`Harry Newton's favorite daughter. Why "favorite?"
`She's his only daughter. Her full name is Claire
`Newton. "Claire" is a form of "Clare," which means
`r "brighP'; from Latin "clarus." Actually, she's both
`1 bright. Brilliant naming, if I might say so. In early
`~e was 19 going on 35. She is currently in her first
`college and her father (i.e. me) is facing annual
`bills for the next four, five or six years. Around the
`iousehold, Claire is known as Princess Claire, a title
`yarned by developing fine culinary and sophisticated
`nunications skills. She is, for example, adept at
`in Chinese food via the telephone. To her credit, she
`leader. Her unbiased, totally objective father (i.e; me)
`iced that she will become the first woman president
`cited States. She has promised me "first sleep" in the
`bedroom, so long as I contribute handsomely to her
`n funds. Look closely. That's me selling Newton's
`Dictionaries out the White House's side door.
`she's a great kid. I couldn't be happier.
`Called Line Address Modification Notification
`er An electronic circuit which sets the level of a sig-
`re the scanning of each line begins to insure that nn
`electronic noise is introduced into the picture signal
`electronics of the video equipment.
`ing Voltage The voltage at which a surge protec-
`ns to stop electricity from getting through. A good
`otector in a 120 volt circuit (the one common in North
`has a clamping voltage of about 135 volts. Damage
`cuter equipment can occur as low as 160 volts.
`entrex Line Assignment Service. A service from local
`;ompanies, which allows Centrex phone subscribers
`ge their class of service by dialing in on a personal
`~r, reaching the phone company's computer and then
`g things themselves —without phone company per
`assisting or hindering.
`:, load your PC with communications software. Dial
`gal central office. Change your Centrex phone num-
`irn on, turn off features. Change pickup groups. Add
`s to speed dialing, etc. Your on-line changes are
`i by the phone company's computers. If they make
`.e. one change doesn't conflict with another), they take
`y early the following day — at which time you can call
`get a report on which took, which didn't and who's eol
`aves calling in person. Is more accurate. And, best of
`es money. Typically just one fiat monthly charge. No
`for any of your changes.
`1. Custom Local Area Signaling Services. It is based
`availability of channel interoffice signaling. Class con-
`number-translation services, such as call-forwar~lin9
`let identification, available within a local exchange of
`access and Transport Area (LATA). CLASS is a serv!ce
`f Bellcore. Some of the phone services which Bellcore
`es for CLASS are Automatic Callback, Automatic
`Calling Number Delivery, Customer Originated Trare,
`five Ringing/Call Waiting, Selective Call Forwarding
`elective Call Rejection. See also Calling Lin,+
`cation.
`n object-oriented programming environment, a cla~>
`the data content of a specific type of object, the coc
`~nipulates it, and the public and private progran~min'>
`;es to that code. See ANI and ISDN.
`also Class 1 and 2, below.
`i Also called Class 1/EIA-578. It's an American Stan
`sect between facsimile application programs and far
`
`NEWTON'S TELECOM DICTIONARY
`
`simile modems for sending and receiving Class 1 faxes. The
`Class 1 interface is an extension of the EIA/TIA's (Electronics
`Industry Association and the Telecommunications Industry
`Association) specification for fax communication, known as
`Group III. Class 1 is a series of Hayes AT commands that can
`pe used by software to control fax boards. In Class 1, both the
`T.30 (the data packet creation and decision making necessary
`for call setup). and ECM/BFT (error-correction mode/binary
`file transfer) are done by the computer. A specification being
`developed (fall of 1991) Class 2, will allow the modem to
`handle these functions in hardware. Industry analysts believe
`Class 2 will be the standard for the long haul, but approval is
`slow. Even so, some modem makers will shortly deliver
`data/fax modems. See also Class 1 Office.
`~~pss 1 Office A regional toil telephone switching center.
`The highest level toll office in AT&T's long distance switching
`i~ierarchy. There are essentially five levels in the hierarchy,
`vrith the lowest level —Class 5 —being those central offices
`owned by the local telephone companies. Each of the classes
`pan complete calls between themselves. But, if the routes are
`busy, then calls automatically climb the hierarchy. A Class 1
`office is the office of "last resort."
`Class 2 Also known as Class 2.0/EIA-592. An American
`standard used between facsimile application programs and
`!acsimile modems for sending and receiving Class 2.0 faxes.
`This class places more of the task of establishing the fax con-
`nection onto the fax modem, while continuing to rely on the
`i;ost's processor to send and receive the image data. The
`Class 2 standard (known as PN-2388) is still under study by
`the EIA's (Electronic Industries Association) TR.29 committee,
`with further revisions expected. See Class 1.
`Hass 2 0#flee The second level in AT&T's long distance
`loll switching hierarchy.
`(lass 3 Office The third level in AT&T's long distance toll
`switching hierarchy.
`Llass 4 Office The fourth level in AT&T's long distance toll
`sv~ilching hierarchy— the major switching center to which toll
`calls from Class 5 offices are sent. In U.S. common carrier tele-
`phony service, a toll center designated "Class 4C' is an office
`,mere assistance in completing incoming calls is provided in
`addition to other traffic. A toll center designated "Class 4P" is
`an office where operators handle only outbound calls, or where
`switching is performed without operator assistance.
`Hass 5 Office An end office. Your local central office. The
`lowest level in the hierarchy of local and long distance switch-
`i~g which AT&T set up when it was "The Bell System." A class
`5 oifiice is a local Central Office that serves as a network entry
`point for station loops and certain special-service lines. Also
`galled an End Office. Classes 1, 2, 3, and 4 are toll offices in
`the telephone network.
`Class A tertifi~ation A Federal Communications
`Commission (FCC) certification that a given make and model
`of computer meets the FCC's Class A limits for radio frequen-
`eyemissions,which are designed for commercial and indus-
`Irial environments. See Class B Certification.
`Mass B Certification A Federal Communications
`~~mmission (FCC) certification that a given make and model
`°f computer meets the FCC's Class b limits for radio frequen-
`cy em6ssions, which are designed to protect radio and televi-
`sion reception to residential neighborhoods from excessive
`radio frequency interference (RFI) generated by computer
`usage. Class B computers also are shielded more efficiently
`from external interface. Computers used at home are more
`likaly (p be surrounded by radio and television equipment. If
`
`you plan to use your computer at home, avoid computers that
`have only Class A certification (that is, they failed Class B).
`Class n Office The way a telephone company defines its
`switching facilities. Class 5 is an end office (local exchange),
`Class 4 is a toll center, Class 3 is a primary switching center,
`Class 2 is a sectional switching center, and Class 1 is a
`regional switching center. See Class 1, Class 2, Class 3,
`Class 4 and Class 5.
`Class Of Emission The set of characteristics of an emis-
`sion, designated by standard symbols, e.g., type of motlula-
`tion ofthe main carrier, modulating signal, type of information
`to be transmitted, and also if appropriate, any additional sig-
`nai characteristics.
`Class Of Office A ranking assigned to switching points in
`the telephone network, determined by function, interfaces and
`transmission needs.
`Class Of Service 1. Each phone in a system may have a
`different collection of privileges and features assigned to it,
`such as access to WATS lines. Class of Service assignments
`if properly organized, can become an important tool in con-
`trolling telephone abuse.
`2. A subgrouping of telephone users for the sake of rate distinc-
`tion. This may distinguish between individual and party lines,
`between Government lines and others, between those permitted
`to make unrestricted international dialed calls and others,
`between business or residence and coin, between fiat rate and
`message rate, and between restricted and extended area service.
`3. A category of data transmission provided in a public data
`network in which the data signaling rate, the terminal operat-
`ing mode, and the code structure (if any) are standardized.
`This is defined within ITU-T Recommendations X.1.
`tlassi~al IP A set of specifications developed by the
`Internet Engineering Task Force (IETF) for the operation of
`LAN-to-LAN IP connectivity over an ATM nehvork.
`Classified Ad Log Records required by Section 76.221 (f)
`of the FCC rules which relat