‘ ‘Harry
`7 4 Newton
`
`,
`
`The Official Dictionary of
`Computer Telephony, Telecommunications,
`Networking, Data Communications,
`Voice Processing and the Internet
`
`

`
`pm
`Newlolfs ’lblecom
`Dictionary
`
`
`
`The Official Dictionary of Computer Telephony,
`Telecommunications, Networking, Data
`Communications, Voice Processing and the Internet
`
`EIGHTH UPDATED AND EXPANDED EDITION
`
`I wrote this book for all of us who are trying to keep up.
`
`It's not a technical book. I explain technical concepts in non—techni—
`cal terms. I figure anyone ought to be able to understand my definitions.
`
`Some of my definitions are several pages long. They're mini-
`essays. They explain the term, its benefits and occasionally a check-
`list on buying and using the item. Sometimes I include warnings. I
`want my dictionary to make you an informed buyer or an informed
`seller. I hope you find the dictionary useful.
`
`HARRY NEWTON
`
`Harry Newton has 25 years in telecommunications. He writes
`
`constantly. He is probably the telecom industry's most prolific writer.
`He is publisher of four monthly magazines - Computer Telephony,
`Teleconnect, Call Center and Imaging. He also founded LAN
`Magazine and Telecom Gear. He is promoter ofthe annual trade con-
`ference and exposition, Computer Telephony Conference -and
`Exposition. He holds an MBA from the Harvard
`
`Business School and an Economics undergraduate
`degree from the University of Sydney, Australia. He
`is not an engineer, but wishes he were. He is the
`
`telecom’s most popular speaker. He has spoken
`before every telecommunications convention and
`
`trade show. He appears as an industry expert on
`national TV.
`
`ISBN 0-936648-60-0
`
`Flatiron Publishing, 12 West 21 Street, New York, NY 10010
`21_2-691-8215 fax 212-691-1191 Mci Mail 101-5032
`
`.. _. ....__.——.-4--—-ca. — L_ —- —_—-n—-.-—--—v———-—._. :j—r>—-
`
`

`
`A Flatiron Publishing, Inc. Book
`Published by Flatiron Publishing, Inc.
`Copyright © 1994 by Harry Newton
`
`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 Flatiron Publishing, Inc., New
`York.
`
`ISBN 0-936648-60-0
`
`Manufactured in the United States of America
`
`Eighth Edition, November 1994
`Cover Designed by Saul Roldan
`Printed at Bookcrafters, Chelsea, MI.
`
`

`
`NEWTON'S TELECOM DICTIONARY
`
`THE "LOGIC" OF MY DICTIONARY
`
`by Harry Newton
`
`I wrote this book for all of us who are trying desperately to keep up.
`
`Telecommunications is now
`1.
`The world 's largest industry.
`from any measure of
`2.
`The world's fastest-changing industry -
`change you can name -
`technology, structure, players, applications and users.
`In one decade, this industry is going from a totally-closed , government-con(cid:173)
`trolled, highly-regulated, monopolistic, bureaucratic, plodding thing to an explod(cid:173)
`ing free-for-all.
`No one has ever written an edition of a 1300-page dictionary every six
`months. No one. Except me. This 8th edition comes fewer than six months after
`the seventh edition. I can't keep working until 4:30 AM every morning. My children
`tell me, "Daddy, get a life!"
`Intel called up and bought 120 of these dictionaries by_ overnight Federal
`Express. $480 in Fedex charges! Incredible. Whoever heard of ordering 51b dic(cid:173)
`tionaries by Fedex? That's the urgency (and madness) of the phenomenon we're
`now in.
`Most technical dictionaries define terms tersely, often in other technical terms.
`As a result they leave you more confused. This dictionary is different, deliberate(cid:173)
`ly so. My definitions tell you what the term is, how it works, how you use it, what
`its benefits are, what its negatives are. I tell you how it fits into the greater scheme
`of things, and occasionally some warnings or checklists if you're buying.
`This is a dictionary to work every day with. Salespeople tell me they include
`the definitions in proposals to customers. Novices tell me they love it because it
`cuts through the clutter. Users explain telecom things to their boss with my defin(cid:173)
`itions. Management uses it to understand telecom technicalities. Lawyers even
`use it in court. (Often they call me as an "expert" witness. It pays better than being
`a juror. But it's probably as boring and as abusive. I always decline.)
`You can give my dictionary to your users, to your customers, to your boss.
`You can even give it to your kids to let them understand what you do. Then they'll
`understand why you, too, have no life.
`I don't claim my dictionary is comprehensive . But each edition gets bigger and
`better. I add, I re-work and I update definitions. I'm always looking for new ones.
`That's an invitation. Send me your product names, your service descriptions, your
`in-house glossaries.
`The best way to get me is through HARRYNEWTON@MCIMAIL.COM or MCI
`Mail account 101-5032 or CompuServe 70600,2451.
`
`ntions,
`
`

`
`NEWTON'S TELECOM DICTIONARY
`HOW TO USE MY DICTIONARY
`My definitions are in ASCII code order - NOT alphabetical order. ASCII is almost
`alphabetical order. In ASCII, capital letters come before lower cas~ letters (who
`knows why) . And ASCII gives some alleged order to hyphens, pen~d~, f~rwa~d
`slashes, etc. Here is the order of the more common characters you II find In thiS
`dictionary:
`Blank Space = ASCII 32
`& (Ampersand) = ASCII 38
`Hyphen -
`= ASCII 45
`= ASCII 46
`Period .
`/ (Forward slash)= ASCII 47
`o (zero)
`= ASCII 48
`1
`= ASCII 49
`2
`= ASCII 50
`3
`=ASC1151
`4
`= ASCII 52
`5
`= ASCII 53
`
`6
`= ASCII 54
`7
`= ASCII 55
`8
`= ASCII 56
`9
`= ASCII 57
`: (colon)
`= ASCII 58
`; (semi colon) = ASCII 59
`A (capital A) = ASCII 65
`Capital letters to ASCII 90
`Lower case letters
`start with a = ASCII 97
`
`ON SPELLING
`My dictionary conforms to American spelling. In other words, unless I've
`specifically stated that it's a British term, my spelling is American. To convert
`American spelling to British and Canadian spelling typically requires adding a sec(cid:173)
`ond "L" in words like signaling and dialing (they're American) and changing "Z" in
`words like analyze to analyse. Center in American is Center. In Britain (and
`Canada), it's Centre. This dictionary contains more British and European words
`than my previous editions - a result of several overseas lecture tours and nag(cid:173)
`ging by "English" speakers, like Canadians, Australians and English people.
`
`ON STYLE
`All high-tech industries make up new words by joining words together. They
`typically start by putting two words next to each other; then, later, they join them
`with a hyphen. An example: Kinder garten. Kinder-garten. and now Kindergarten.
`Then, with age and familiarity, the hyphen tends to disappear.
`Sometimes it's just a matter of personal choice. Some people spell database
`as one word. Some as two, i.e. data base. I prefer it as one, since it has acquired
`its own logic by now. Sometimes it's a matter of how it looks. I prefer T1 (T-one)
`as T-1, simply because T-1 is easier to recognize on paper. Sometimes it's a mat(cid:173)
`ter of being easier to read. I define co-location as co-location. Websters spells it
`collocation, with two Ls, one more than mine. I think mine is more logical.
`There are no rights or wrongs in the spelling business, except that my dictio(cid:173)
`nary is now right, because it's the biggest seller (by far) and because lawyers use
`it in court. (God help the justice system.)
`
`ii
`
`

`
`,CII is almost
`, letters (who
`iods, forward
`I'll find in this
`
`unless I've
`To convert
`Iding a sec(cid:173)
`nging liZ" in
`3ritain (and
`)ean words
`'S and nag(cid:173)
`eople.
`
`!ther. They
`,join them
`Idergarten.
`
`I database
`s acquired
`f1 (T-one)
`it's a mat(cid:173)
`rs spells it
`:al.
`my dictio(cid:173)
`wyers use
`
`NEWTON'S TELECOM DICTIONARY
`
`Plurals give trouble. The plural of PBX is PBXs, not PBX's. The plural of PC
`is PCs, not PC's, despite what the New York Times says. The Wall Street Journal
`and all the major computer magazines agree with me. So there.
`In this book, the numbers one through nine are spelled out. Above nine, the
`numbers are written as arabic numerals, i.e. 10, 11, 12, etc. I follow the style Andy
`Moore established in TELECONNECT Magazine, and the one he has so rigor(cid:173)
`ously held us to for 15 years. Yes, it's been that long. (He's on his second wife,
`first child. I'm on my first wife . Two children , Claire and Michael. Wife , Susan.
`They have a life without me.)
`
`THANK YOU.
`A big ''Thank You" to the dozens of people and dozens of companies who
`helped. I bet I leave some of you out. If so, I apologize.
`Among the manufacturers, special thanks to Amdahl, Anixter, Aspect
`Telecommunications, AT&T, Bellcore, Dialogic, Ecos Electronics, General Cable,
`Micom, MCI, NEC, Newbridge Networks, New York Telephone (now Nynex),
`Northern Telecom, Racal Data, Ricoh , Sharp and Teknekron . They'll recognize
`some of their words in this dictionary. Among the magazines I borrowed (or stole),
`the best were PC Magazine and our own TELECONNECT, Call Center and
`IMAGING Magazines. Special thank yous also to internetworking expert, Tad
`Witkowicz at CrossComm , Marlboro MA. ; Ken Guy of Micom, Simi Valley (near
`LA) ; Michael Marcus, president of Able Communications, an excellent intercon(cid:173)
`nect company based in Scardsale NY, Frank Derfler of PC Magazine; Chris
`Gahan of 3Com; Jeff Deneen of the Norstar Division of Northern Telecom in
`Nashville; Stephen Doster of Telco Research in Nashville; bugging expert Jim
`Ross of Ross Engineering, Adamstown, MD; wiring experts John and Carl
`Siemon of The Siemon Company, Watertown CT; Kelly Christiansen, Joe Staples,
`Joe Smith, Blaine Homer and the fine folk at Novell, the local area network com(cid:173)
`pany in Provo, UT; to Jim Gordon and Parker Ladd at TCS Communications,
`Nashville, TN, the people who do workforce management software for automatic
`call distributors; to Judy Marterie and the electricity wiring, grounding and test
`experts at Ecos Electronics Corporation in Oak Park, II; to John Perri of SoftCom ,
`NYC; to John Taylor of GammaLink, a Sunnyvale, CA company which produces
`beautiful fax products and extremely helpful documentation on fax technology; to
`Charles Fitzgerald at Microsoft and Herman D'Hooge at Intel who jOintly helped
`created Windows Telephony; to Bill Flanagan who's written fine books on T-1 and
`voice and data networking; to Jane Laino of Corporate Communications
`Consultants, NYC; to Henry Baird of Seattle consultants Baird & Associates; to
`Sharon O'Brien formerly of Hayes Microcomputer Products in Norcross (Atlanta) ;
`to Howard Bubb, Ed Margulies, Terry Henry, John Landau, Jim Shinn and Nick
`Zwick at leading voice processing component manufacturer, Dialogic Corporation
`of Parsippany, NJ; to AI Wokas of voice processing company Rhetorex in San
`Jose, CA; to Alison Golan of networking company, Interphase Corporation in
`Dallas, which allowed me to steal some of the definitions from their excellent
`booklet, "A Hitchhiker's Guide to Internetworking Terms and Acronyms;" to Ian
`Angus at the Angus TeleManagement Group in Ajax, Ontario, who embarrassed
`me into expanding my Canadian coverage .
`
`iii
`
`

`
`NEWTON'S TELECOM DICTIONARY
`
`At liff Davis, which publishes this dictionary on CD-ROM discs (for your copy,
`call 800-827-7889 or 212-503-4400 or in England 44-344-714-441), I'm grateful
`to Tom Pfaw, Sylvia Schmidt and Paul Gudelis. In my own office, I'm very grate(cid:173)
`ful to Muriel Fullam, Christine Kern, Rose Bodin, Andy Moore and Jennifer
`Cooper-Farrow.
`
`Without all these wonderful people, this dictionary wouldn't be as good as it's
`actually turning out. If I sound surprised, you're right. It's now the largest-selling
`telecommunications dictionary in the world.
`
`If I've left any definitions out, or if some of my definitions are unclear, contact
`me.
`
`I wrote this dictionary on a series of ever-newer, ever-faster Toshiba laptops
`(very reliable machines) using The Semware Editor, a very beautiful text editor,
`which Sammy Mitchell of Marietta, GA wrote. The Toshiba laptop for this dictio(cid:173)
`nary was the T 4800CT, their top of the line - until they announced a T 4900CT in
`the late Fall of 1994. Progress! Jennifer and Christine Kern (ne. Fullam) typeset
`it on a Macintosh Quadra using QuarkXpress and Adobe Illustrator. Bookcrafters
`in Chelsea, Michigan printed it. I'm responsible for it.
`
`published by Flatiron Publishing, Inc.
`12 West 21 Street
`New York, NY 10010
`212-691-8215 • 800-999-0345
`800-L1BRARY. Fax 212-691-1191
`Electronic Mail 212-989-4675
`MCI Mail 101-5032
`CompuServe 70600,2451
`
`ISBN # 0-936648-60-0
`November, 1994
`
`iv
`
`

`
`NARY
`
`I is four times faste
`(1), while PCM takth~
`per second, while as q~
`j theoretically prod De~
`an ear can't hearthlJCe a
`ersation.
`e OH,
`Iy its use of feWer
`.
`,patible with eaCh o~ts,
`you have to conva
`Elr.
`je facto digital enc~~he
`tally encoding VOice ~n9
`they can be made ~ I1rj
`lck to analog VOice) ~rn.
`lIy put twenty fOUr 64 ne
`all it T-1. The Europ~~
`tho Thus, you can't dir S
`Jt there are "black box~:
`as available.)
`S
`modulation in which the
`gnal itself. A normal delta
`_TA MODULATION.
`Jally motivated by an irre.
`urk and add my two cents
`,
`
`:alls from phone users,_
`til routes for completing I
`lback Queue (RBQ)- ttl
`les available - or an Oft.
`)nnected to the next avaJ.
`~T&T. Most modern PBXs
`
`DAMA.
`s share a communicatiOll
`. user on the network "
`I the circuit is deactivated
`,
`
`and on a power system'
`
`d by a facility. The de~
`actical load) and non ~
`Ie proper demand fac
`f1lOIf
`th e sum total.
`in a PC of virtual rT1e
`faiJ
`a in response to page ~
`support for time sen
`
`HEWTON'S TELECOM DICTIONARY
`
`uch as video and multimedia as part of the proposed 100BaseVG
`licatiOns srin 100Mbit/s over voice grade UTP (Unshielded Twisted Pair)
`aPP dard ofte a 1ng and allocating access to the network centrally, at a hub rather
`:S~~e, BY ~~Vi~ual workstations, sufficient bandwidth for the particular applica(cid:173)
`C'l n from In teed on demand. Users, say its proponents, can be assured of reli(cid:173)
`~:n is gu~r~us transmission of information.
`: b1e, cont; pUBLISHING 1. The production of just the number of printed doc-
`I~" need at the present time, as in "just in time." 2. The immediate pro(cid:173)
`~(f1e~ts yOU rinted documents which have been created and stored electronically.
`ductlon of: SERVICE In ISDN applications, a telecommunications service that
`"E~" an immediate communication path in response to a user request
`establiShe~gh user-network signaling.
`made thrO or DEMARK (Pronounced D-Mark.) The demarcation point between
`DI~RCthat comes in from your local telephone company and the wiring you
`your CPE (Customer Provided
`the wlnnghook up your own telephone system -
`ins~1I to t) wiring. A De-Marc might be anything as simple as an REJ-11 C jack
`EQUIpmen or an REJ- 14C (two trunks) or an REJ-21 X (up to 25 trunks) or a 66-
`(one trun~) unchdown block on one side of which the telephone company punch(cid:173)
`i~ trunks and on the other, you punch down your connections into your
`blOCk -
`as dOW~ystem . On a 66 block, there are little metal clips called "bridging clips"
`phOne
`en you and the phone company. Lifting these clips off cuts your equipment
`t)9tW~he hone company's trunks. This way you can quickly see whose fault it is.
`~n it's ~ours. But, if you think it's theirs and they come and find it's yours, they'll
`bill you megabucks. See DEMARCATION POINT or DEMARCATION STRIP.
`llMARCATION POINT The pOint of a demarcation and/or interconnection
`!)etWeen telephone company communications facilities and terminal equipment,
`protective apparatus, or wiring at a subscriber's premises. Carrier-installed facil(cid:173)
`Ities at or constituting the demarcation point consist of a wire or a jack conform-
`100 to Subpart F of Part 68 of the FCC Rules.
`IlMARCATION STRIP The terminal strip or block (typically a 66 block) which
`1$ the physical interface between the phone company's lines and the lines going
`directly to your own phone system. See also DEMARC.
`IIMKO Denmark Elektriske MaterielKOntrol (Denmark Testing Laboratory).
`DlMOCRATICALLY SYNCHRONIZED NETWORK A mutually synchro(cid:173)
`flized network in which all clocks in the network are of equal status and exert
`aqual amounts of control on the others.
`= ODULATION The process of retrieving an electrical signal from a carrier
`or wave. The reverse of modulation. See MODEM.
`:=LTt~bPLEX ~EM~X. To separate two or more signals previously combined
`DbA pa I Ie multiplexing eqUipment.
`fatter ~rL:Pt· LEXER A device that pulls several streams of data out of a bigger,
`"'aa
`er stream of data
`.
`COmbined"w~~ING A process applied to a multiplex signal for recovering signals
`"-UX
`In It and for restoring the distinct individual channels of the signals.
`Jargon for demultiplexer.
`
`~U~
`
`

`
`'IONARY
`
`;wering of incon,'
`some trunks , an~l')a ~Ii~ .
`I')I've
`r~
`feature which all
`10ne system. M~is 'Y0ll
`mOde
`
`:ables to a faceplat
`e, aSfO!
`
`'ell Open Datalin
`twork interface ak Intert~,,_
`, nd \ •. ~ "'Or
`
`proved mOdulation Sch
`over shielded and Un h~tne
`s lelG.
`
`mth of a farad, the un~ f/
`
`ed off to the right hand skfe
`
`:hod used in newer Group 3
`
`tasy to remember, usually
`or process. LASER is f
`
`A way of dialing using char·
`Mnemonic comes from the
`)f remembering something
`
`esented by the approprialt
`nple, "P" to "Play", "A" to
`
`, error-correcting a~1c~
`:0 14.4 Kbps. See
`ftt
`)NTROL PROTOCOLS
`
`t unit permanently mounted
`
`NEWTON'S TELECOM DICTIONARY
`:r- Mobile data is a generic term used to describe data communi-
`,I "IS "-h the air from and to field workers -
`from package deliverers, to
`--~ns thrO~panies (to track cars), to field service personnel, to law enforcement
`t8~re(1tal~~cking license plates.
`~cialS C ",OUNTING KIT An optional cellular phone accessory that allows a
`O,I"IS e or portable to be connected to a vehicle's power supply and anten(cid:173)
`~l1sportablrebY boosting power and improving reception. Sometimes referred to
`ll""lead, t~eor car mounting kit. Some of these kits are very expensive. Check the
`fI8 a car Kit k'lt before you buy your phone.
`as
`f the
`price 0 PHONE One term for a cellular phone. There are four main types of
`.. o'I"~ones - mobile (also called car phone), transportable, portable and per(cid:173)
`~lIular P obile phone is attached to the vehicle, the vehicle's battery and has an
`e1Iernal :5 of power. Mobile telephone service is provided from a broadcast point
`)Dna!. A rTlnten na. The mobile phone (the car phone) transmits with a standard
`~ree wa ithin range of the moving vehicle. That range is called a "cell." The
`K)C3ted ~ oint in turn is connected to the public network so that calls can be
`Df08dC~:d ~o or from any stationary telephone, i.e. one connected to a land line.
`tom~~LLULAR and CAR PHONE.
`see IILE TERM I NA":ED . The term used to describe a call where the destina(cid:173)
`"Oof the call is a mobile (I.e. cellular) telephone.
`:'IILE UNIT The cellular telephone equipment installed in a vehicle. It con(cid:173)
`$ISfS of a transceiver, control head, handset and antenna.
`MOIILINK A "unified" cellular phone service covering 83% of North America's
`population. It is a consortium of six Bell cellular operators and some Canadian cel(cid:173)
`kJar operators. The idea is simple. Anyone calling a subscriber of one of these
`(D(Ilpanies would have his call automatically routed to the subscriber, no matter
`.t\efe in Mobilink that subscriber was. Before Mobilink, you had to know where
`. Jlt person was you wanted and then dial a bunch of complex codes to get to him.
`MODAL DISPEDION Digital pulse rounding in lightwave communications
`ftat takes place because of the slightly different paths followed by the laser light
`rays as they arrive at the detector slightly out of phase.
`MODAL DISTRIBUTION 1. In an optical fiber operating at a single wave(cid:173)
`length, the number of modes supported by the fiber, and their propagation time
`differences. 2. In an optical fiber operating at multiple wavelengths simultaneous(cid:173)
`ly. the separation in wavelengths among the modes being supported by the fiber.
`IIODAL LOSS In an open waveguide, such as an optical fiber, a loss of ener(cid:173)
`IY on the part of an electromagnetic wave due to obstacles outside the wave(cid:173)
`
`=: abrupt c~anges in direction of the waveguide, or other anomalies, that
`
`110 changes In the propagation mode of the wave in the waveguide.
`flrJt~eE MOde is essentially a switch inside a computer that makes it run like
`110 r computer, usually an older one.
`JaI Si:~~ Acronym for MOdulator/DEModulator. Equipment which converts digi(cid:173)
`~ (dig~ ~o) analog Signals and vice-versa. Modems are used to send data sig(cid:173)
`tI'Iodulatesath o~er the telephone network, which usually is analog. The Modem
`e 1's" and "D's" into tones which can be carried by the phone net-
`
`659
`
`

`
`NEWTON'S TELECOM DICTIONAR~
`
`work. At the other end, the demodulator part of the modem cOnv
`back into digital 1 's and O's. See MODEM ELIMINATOR, M~~S the
`MODEM STANDARDS, MODULATION PROTOCOLS and SERIAL f:l12rv, ~to
`MODEM ELIMINATOR A wiring device designed to replace tw ORl a '"
`connects equipment over a distance of up to several hundred feet a l'l1o(je
`rtls
`nous systems, this is a simple cable . Here is a specific application u~·ln aSyn
`Eliminator: You can connect a PC to a printer, or a PC to another P~~g a M~ n
`cable. But you can only go a certain distance - maybe 100 feet. A'nter USi e
`traditional solution has been to use a modem and go over traditional ft~r thatt\g·
`Instead, you can connect the two devices directly by wire uSing one lin .
`Eliminator. There are two advantages of a Modem Eliminator oVe a MOQ~
`modem. The eliminator is cheaper and it can often transmit faster. A~ a nOfltia,
`Glasgal Communications, there are many cases where it is either unnCor(jing
`cumbersome or too expensive to interconnect terminals using mOdems ec~s~
`vers in an experimental or a very short-haul environment. A modem or.hne a ..
`functionally resembles two modems back-to-back on a leased line and ~I~rnlna
`saves the cost of two modems and a line in many situations.
`erefOle
`MODEM FALLBACK When the telephone line quality is not gOOd en
`accommodate the top rated speed of a modem -
`for example 14,400 b oUQh
`initially to 9,600 bps, then if nec~s~ -- ~
`modem drops down to lower speeds -
`4,800 bps, or even down to 2,400 bps.
`ary"
`MODEM POOL A collection of modems which a user" can dial up from hi
`minai, access one and use that one to make a data call over the SWitchedSt~
`phone network. Modem pools are obviously designed to allow many user: It
`share few modems, thus saving on modems. Now that modems have be
`less expensive, the advantages of modem pooling are no longer as great. ~
`are also some advantages in having a modem right next to your terminal or COrn.
`puter -
`namely you can see how it is functioning. And modems have lights ~
`indicate what they're doing. One of the most useful lights on most modems ina.
`cates whether the line is "off hook" or not. It is possible for your computer t
`instruct your modem to hang up the line and for your modem to forget to do .
`leaving you with a huge phone bill. One problem with giving people their O'M\
`modems is they (the modems) have a tendency to get pinched. It's hard to SCfft
`down modems. Harder, anyway, than computers and disk drives.
`MODEM SERVER A networked computer with a modem or group of modems
`attached to it that allows network users to share the modems for outbound calls
`MODEM STANDARDS Definitions of electrical and telecommunications cIW·
`acteristics which enable modems from dissimilar manufacturers to speak to ead!
`other. BeIl103 ... US standard for 300 bps; CCID Y.21 ... International standard b
`300 bps; Bell 212A ... US standard for 1200 bps; CCID Y.22 ... lnternational stan'
`dard for 1200 bps; CCITT V.22 bis ... US and international standard for 2400 bps
`CCITT Y.23 .. . International videotex standard (1200/75 bps or 75/1 200 bps). see
`also HAYES COMMAND SET and Y.SERIES recommendations, i.e. V.34.
`MODEM TURNAROUND TIME The time needed for a half-duplex modern
`(an old-fashioned one) to reverse its transmission direction.
`pal'
`MODERATOR A moderator is a person who controls what gets posted to a
`
`660
`
`

`
`Converts
`the to
`~, MOD
`ERIAL f::JtM ~O
`ace tw Of1l Q(
`d. feet.~nl1'1o(jel'l1s.
`"
`ltlon USi asyt'lc
`)ther pr~g a MOd to,
`~eet. A~ter lJSin e~
`dltional p~r that, 901
`'e USing ~ne H~
`ator oVer MOd~
`faste r A a nOr
`either' unCnCOrding
`eCes~ .. _
`mOderns Or r WQl'1
`~ mOdem el' I~e Or
`Imln ..
`d I·
`Ine and th
`ere10re
`
`''Q
`
`lOt gOOd enoug
`e 14,.400 bps __
`:hen If necessa ry,
`
`t4EYlTON'S TELECOM DICTIONARY
`
`neWsgroup, A moderator is used to ensure that a newsgroup's
`Internet the agreed upon subject matter. A newsgroup mayor may not
`'cK to
`~,18f
`'-ie 5tl derator.
`~ 11",0
`.EQUENCY MODULATION MFM. An encoding scheme used
`!live".,.'" Fon the magnetic surfaces of hard disks. It is the oldest and slowest
`JJD~rd dataster hard disk interface standards. RLL (Run Length Limited encod-
`9 e Winch~r standard , for example.
`~i511 new HUFFMAN A one-dimensional data-compression scheme that
`.dt".'.'" data in a horizontal direction only. Allows no transmission of redun(cid:173)
`"'presses
`~ data, READ A two-dimensional coding scheme for facsimile machines
`,.o".fl~~ the data compression of the vertical line ~nd that concentrates on
`~ hand~een the lines and within given characters.
`~ be • Equipment is said to be modular when it is made of "plug-in units"
`~""-be added together to make the system larger, improve its capabilities
`~ c~~ its size. There are very few phone systems that are truly modular.
`~eXpa ..-, JACK A device that conforms to the Code of Federations, Title 47,
`flJf!s" which defines size and configuration of all units that are permitted for con(cid:173)
`,.rt~ n' to the public telephone network.
`~ ULA. PLUG A series of connecting devices adopted by the FCC as the
`: :rd interface for telephone and data equipment to the public network. The
`common is the RJ-11, used to connect a single line phone.
`,..ULA. WINDOWS Microsoft's name for a family of stripped down ver(cid:173)
`_ of Windows that are intended to be built into a wide variety of devices other
`
`'*' pes, including telephone systems and office machines, such as fax
`
`dial up from his ter.
`r the switched tale.
`low many users
`iems have become
`ger as great. Thert
`lur terminal or com.
`.-:hines. See also AT WORK and WINDOWS TELEPHONY.
`iems have lights to
`IODULATED WAVES Alternating current waves which have their amplitude
`most modems inct(cid:173)
`Iliad periodically. The Signals transmitted by a radio station are examples of a
`r your computer "
`llldulated wave.
`" to forget to do
`g people their own
`IODULATION The process of varying some characteristic of the electrical car(cid:173)
`d. It's hard to screw
`wave as the information to be transmitted on that carrier wave varies. Three
`les.
`of modulation are commonly used for communications, Amplitude
`IIDdulation, Frequency Modulation and Phase Modulation. And there are varia(cid:173)
`r group of moderN
`. on these themes called Phase Shift Keying (PSK) and Quadrature
`for outbound callS
`~itude Modulation (QAM) .
`11munications d*'
`IODuLATION INDEX In angle modulation, the ratio of the frequency devia(cid:173)
`irs to speak to eacfI
`lin of the modulated Signal to the frequency of a sinusoidal modulating signal.
`ational standard tt
`~ulation index is numerically equal to the phase deviation in radians.
`International -
`;dard for 2400 bPI
`IIadem LATION PROTOCOLS Modem stands for MOdulator/DEModulator. A
`75/1200 bps). set
`~ converts digital signals generated by the computer into analog signals
`ns, i.e. V34.
`!'&Jog ca~ be transmitted over an analog telephone line and transforms incoming
`half-duplex ~
`"-:ode ~~gna~s . into their digital equivalents. The specific techniques used to
`~s e digital bits into analog signals are called modulation protocols. The
`~er mOdulation protocols define the exact methods of encoding and the data
`speed . In fact, you cannot have a modem without modulation protocols.
`
`ets posted to Ii par'
`
`661
`
`

`
`NEWTON'S TELECOM DICTIONARY
`
`A modem typically supports more than one modulation protocol.
`The raw speed (the speed without data compression) of a modem is d
`by the modulation protocols. A 2400 bps Hayes-compatible modem typ~terll)i/")
`leally SuE!(!
`ports the following modulation protocols:
`p.
`Bell 103
`(300 bps U.S. Standard)
`Bell 212A
`(1200 bps U.S. Standard)
`CCITT V.22
`(1200 bps standard used outside the U.S.)
`CCITT V.22 bis
`(2400 bps International Standard)
`Some 2400 bps modems also support the following protocols:
`(300 bps standard used outside the U.S.)
`CCITT V.21
`CCITT V.23
`(1200/75 and 75/1200 bps, used in Europe)
`There are two standard modulation protocols for high-speed mOdems: V
`V.32 bis. Both are standards established by the CCITT. V.32 is the stand32 and
`9,600 (and 4,800) bps modems. V.32 was adopted by the CCITI in 1984. ard for
`V.32 bis, established in early 1991, is the CCITI standard for 14 400
`modems. A V.32 bis modem also can fall back to 12,000, 9,600, 7,200 and 4 bps
`bps. V.32 bis is downwardly compatible with V.32.
`,800
`Unlike 2400 bps modems where a single modulation protocol (V.22 bis) is
`ported by all modem makers, there are several proprietary modulation proto~ur'
`used by V.32 and V.32 bis modems from different manufacturers. Until the ree Os
`surge of V.32 modems, the U.S. Robotics HST (High Speech Technology) Was ~
`de facto standard in the PC-based BBS community. The original Courier HS e
`modem ran at 9,600 bps. U.S. Robotics later improved the speed of the COUriet
`HST to 14,400 bps.
`Telebit introduced the TrailBlazer in 1985 which used a proprietary modulation
`protocol called PEP (Packetized Ensemble Protocol) . Hayes entered the high.
`speed modem arena in 1987 with the introduction of the V-series Smartmodem
`9600. The modem used a proprietary modulation protocol called Express 96 (alS6
`known as Hayes "Ping Pong" protocol) . The V-series modems have not been as
`successful as the U.S. Robotics or the Telebit modems.
`Two modems can establish a connection only when they share a common mod·
`ulation protocol. To connect at high speed, two modems have to support the same
`high-speed modulation protocol. Therefore, a modem with a proprietary modula'
`tion protocol can only establish a high-speed connection with another m~dern
`from the same manufacturer. A U.S. Robotics HST modem can only establiSh 8
`high-speed connection (at 9600 or 14400 bps) with another HST or an USA Dual
`Standard modem. A Courier HST modem cannot establish a high-speed con~ec·
`tion with a Courier V.32 bis modem. They can only connect at 2400 bps. All hit
`speed modems in the market support the CCITT V.22 bis modulation protoco .
`On the other hand, two V.32 modems can talk to each other at 9600 bps. r:y
`
`do not have to be from the same manufacturer. Two V.32 bis modems C~~600
`to each other at 14,400 bps. A V.32 modem can talk to a V.32 bis modem ~ bod
`bps. This is because these are public standards promulgated by a pUbliC
`called CCITI.
`
`

`
`~RY
`
`NEWTON'S TELECOM DICTIONARY
`
`rking on a new modem standard, dubbed V.fast. If all goes well, the
`111 is WO standard can materialize before 1993. A V.fast modem is expected
`cc~ [110de~w speed of 19,200-24,000 bps over standard dial-up telephone lines.
`:reach. ~ ion on Modulation Protocols with thanks to modem expert, Patrick Chen.
`fll1rt liON RATE The reciprocal of the measure of the shortest nominal
`flli5 de
`~"I'II~I between successive significant instants of the modulated signal.
`rV liON SUPPRESSION In the reception of an amplitude-modulated
`Ufl1e inte
`~"I'II~apparent reduction in the depth of modulation of a wanted signal,
`signal, ~ presence, at the detector, of a stronger unwanted signal.
`cau5e~~'OR A device which converts a voice or data signal into a form that
`p.4,,1' transmitted.
`can be LO Term used to express the maximum number of states for a counter.
`_01'11 describe several packet-switched network parameters, such as packet
`counted from 0 to 7). When the maximum
`Used to (usually set to modulo 8 -
`flLJrTlb~r exceeded, the counter is reset to O.
`unt IS
`cO ULO N In communications, refers to a quantity, such as the number of
`p.40D or packets to be counted before the counter res