`
`--~-. --- ·-
`
`
`
`BY HARRY NEWTON
`- - -- -- - - --
`
`. -~~
`
`Comcast, Ex. 1230
`
`1
`
`Comcast, Ex. 1230
`
`

`

`Uli:IIIJW'll'ftlllW~ HUCOM DICTIONARY
`copyright © 2000 Harry Newton
`Email: Harry Newton@Technologylnvestor.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 by Telecom Books
`An imprint of CMP Media Inc.
`12 West 21 Street
`New York, NY 10010
`
`ISBN # 1-57820-053-9
`
`Sixteenth Edition, Expanded and Updated, February 2000
`
`For individual orders, and for information on special discounts for quantity orders,
`please contact:
`
`Telecom Books
`6600 Silacci Way
`Gilroy, CA 95020
`Tel: 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
`
`Manufactured in the United States of America
`
`2
`
`

`

`The Official Dictionary of
`Telecommunications & the Internet
`
`16th Updated, Expanded and Much
`Improved Edition
`
`3
`
`

`

`NEWTON'S TELECOM DICTIONARY
`
`incorporated into ISO/IEC 10038. Works at the MAC level.
`802.1 E IEEE standard for LAN and MAN load protocols.
`Approved in 1990, formed the basis for ISO/IEC 15802-4.
`802.1 IF Standard for defining network management informa(cid:173)
`tion specified in 802 umbrella standards. Approved in 1993.
`802.1 G A developing standard tor remote bridging at the
`MAC layer.
`802.1 H IEEE practices recommended tor bridging Ethernet
`LANs at the MAC layer. Approved in 1995.
`802.11 IEEE standard tor using FOOi (Fiber Distributed Data
`Interface) as a MAC-layer bridge. Approved in 1992, the stan(cid:173)
`dard was incorporated into ISO/IEC 10038.
`802. U IEEE standard for LAN connectivity using MAC-layer
`bridges. A supplement to 802.10, it was approved in 1996.
`802.1 K IEEE standard tor the discovery and dynamic control
`of network management information. Approved in 1993. In
`conjunction with 802.1B, was the basis for ISO/IEC 15802-2.
`802.1 M A conformance statement tor 802.1 E, it addresses
`definitions and protocols for system
`load management.
`Approved in 1993, ii was incorporated into ISO/IEC 15802-4.
`802.1 P IEEE extension of 802.1 D. Specification for the use
`of MAC-layer bridges in filtering and expediting multicast
`traffic. Prioritization of traffic is accomplished through the
`addition of a 3-bit, priority value in the frame header. Eight
`topology-independent priority values (0-7) are specified, with
`all eight values mapping directly into 802.4 and 802.6.
`Switches that support 802.1 P and 802.10 provide a frame(cid:173)
`work for bandwidth prioritization. Essentially what all these
`words mean is that you can assign a priority to the type of
`The QoS feature on the Catalyst 6000 Family of switches pri(cid:173)
`oritizes network traffic with IEEE 802.1 p class-of-service
`(CoS) values that allow network devices to recognize and
`deliver high-priority traffic in a predictable manner. When
`congestion occurs, QoS drops low-priority traffic to allow
`delivery of high-priority traffic. See also 802.10.
`802.1 Q IEEE specification for implementation of VLANs in
`Layer 2 LAN switches, with emphasis on Ethernet. Similar to
`802.1P, prioritization of traffic is accomplished through an
`additional four bytes of data in the frame header. Most data
`fields in this addition to the header are specific to VLAN oper(cid:173)
`ation. Also included is a field which provides the same 3-bit
`priority flag specified in 802.1 P's priority-mapping scheme.
`In addition to conventional data traffic, 802.10 supports voice
`and video transmission through Ethernet switches. In short,
`the 802.10 specification provides a 32-bit header tor VLAN
`frame tagging. Each 802.10 tag sits in an Ethernet frame
`between the source address field and the media access con(cid:173)
`trol (MAC) client type/length field.
`802.2 The IEEE standard tor Logical Link Control, primari(cid:173)
`ly using MAC-layer bridges, in LAN and MAN domains.
`Originally approved in 1989, and updated in 1994. A format
`used tor frames of data sent on Ethernet, token ring and sev(cid:173)
`eral other types of local area networks. Now the format favored
`by Novel I tor NetWare 4.x LANs over the 802.3.
`802.2 SNAP (Cub-Network Access Protocol). A variation
`on the 802.2/802.3 scheme which expands the 802.2 LLAMA
`header to provide sufficient space in the header to identify
`almost any network protocol.
`802.3 IEEE standard for carrier sense multiple access with
`collision detection (CSMA/CD). A physical layer standard
`specifying a LAN with a CSMA/CD access method on a bus
`topology. Ethernet and Starlan both follow the 802.3 standard.
`Typically they transmit at 10 megabits per second (Mbps).
`The theoretical limit of Ethernet, measured in 64 byte packets,
`
`Network) data communications developed through the IEEE's
`Project 802. The standards also include an overview of rec-
`ommended networking architectures, approved in 1990. The
`802 standards follow a unique numbering convention. A
`number followed by a capital letter denotes a standalone stan-
`dard; a number iollowed by a lower case letter denotes either
`a supplement tc a standard, or a part of a multiple-number
`standard (e.g., 802.1 & 802.3). The 802 standards segment
`the data link layer into two sublayers:
`1. A Medium Access Control (MAC) layer that includes spe-
`cific methods tor gaining access to the LAN (Local Area
`Network). These methods -
`such as Ethernet's random
`access method and Token Ring's token procedure -
`are in
`the 802.3, 802.5 and 802.6 standards.
`2. A Logical Link Control (LLC) Layer, described in the 802.2
`standard, that provides tor connection establishment, data
`transfer, and connection termination services. LLC specifies
`three types of communications links:
`• An Unacknowledged connectionless Link, where the send-
`ing and receiving devices do not set up a connection before
`transmitting. Instead, messages are sent on a "best try" basis
`and there is no provision tor error detection, error recovery,
`and message sequencing. This type of link is best suited tor
`applications where the higher layer protocols can provide the
`error correction and functions, or where the loss of broadcast
`messages is not critical.
`• A Connection-mode Link, where a connection between
`message source and destination is established prior to trans-
`mission. This type of link works best in applications, such as
`file transfer, where large amounts of data are being transmit(cid:173)
`ted at one time.
`• An Acknowledgedconnectionless Link that, as its name
`indicates, provides tor acknowledgement of messages with(cid:173)
`out burdening the receiving devices with maintaining a con(cid:173)
`nection. For this reason, it is most often used tor applications
`where a central processor communicates with a large number
`of devices with limited processing capabilities.
`802.1 IEEE standard for overall architecture of LANs and
`internetworking.
`80.2.11 IEEE standard tor wireless LANs; intended to provide
`for interoperability of wireless LAN products from different man(cid:173)
`ufacturers. It was ratified on June 26, 1997. The standard
`defines the over-the-air interface -
`the protocol that wireless
`stations will use to talk to each other or to access points. 802.11
`does not define the protocol tor backbone or wired networks.
`802.11 defines both the Physical (PHY) and Medium Access
`Control (MAC) protocols tor wireless LANs. Specifically, the
`HY spec includes three transmission options -
`one infrared
`IR), two radio frequency
`RF
`which include direct
`sequence spread spectrum and frequency hopping spread spec(cid:173)
`trum. Direct sequence data rates clock in at 2 Mbps and fre(cid:173)
`quency hopping clocks in at 1 Mbps. The IR runs at 1 Mbps with
`an optional implementation to 2 Mbps. The MAC protocol
`Works well with standard Ethernet, making wired and wireless
`nodes on an enterprise LAN logically indistinguishable.
`802. U Standard for 100VG-AnyLAN. Addresses 100 Mbps
`demand-priority access method physical-layer and repeater
`specifications Approved in 1995.
`802.1 B Standard for LAN/WAN management, approved in
`1992; along with 802.1k, became the basis of ISO/IEC
`15802-2,
`
`(P
`
`Der-
`1ice
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`
`. 81>2.1 D IEEE standard tor interconnecting LANs through
`lL
`
`MAC bridges (specifically between 802.3, 802.4, and 802.5
`etworks). The standard was approved in 1990, and was
`
`19
`
`4
`
`

`

`.
`
`acro§ miss at .
`v
`r
`
`of DAVIC 1.0 smelfrdimsaeb
`
`.7“,
`up 5‘ ’*‘
`._
`broadcast and interactiveml!
`
`. ms.
`- waswflfi
`tions such as TV distribution, near Viki in
`
`demand, and basic forms of teleshoppm m
`'_
`i
`the organizations examining the developingMini
`'
`.
`> d-
`-
`VDSL (Very-high-bit—rate Digital Subscriber Line). m ‘s
`um:
`
`Hflflkfldhh
`not!
`intended for video applications. www.davic.org
`bhfldmmmb
`hm
`Day-Of-Wuk Futon A call center term. A historical
`
`“(firm
`per. 75 (M B Wm 1m M
`pattern consisting oi seven factors, one for each day of the
`
`IoudaWallrnmmgeLandchhAisa'fi
`week,
`that defines the typical distribution of call arrival
`,
`.
`-SMM
`at20teetawayfrorntheengineJhe'A'
`7-
`
`throughout the week. Each factor measures how far call vol-
`filter which is used to take into accountthetmt
`.»
`- final term l10l
`ume on that day deviates from the average daily call volume.
`
`° '
`7
`.
`less sensitive to very low and very high
`.H
`15 Mom
`dB 1. Decibel. A unit of measure of signal strength, usually
`
`system is used for measuring background ~-
`.- -.
`.
`.
`the relationship between a transmitted signal and a standard
`puter fans or office noise. A system with a d" a -,
`Died Carrier Ml
`signal source. dB stands for decibels, which is a way to repre-
`i Data Communlc
`doc is used when very loud sounds are being
`sent logarithmic ratios. Since 3 dB number is a ratio,
`it must
`
`.
`definition courtesy APC.
`section and line
`
`always be a ratio between two things. The dB number is equal
`dmnels to comtr
`. »
`DBI Don't Believe It. This is used in telecontrol
`
`to 20 times the log of the ratio between two numbers. A ratio
`SONET term.
`electricity transmission/distribution systems to .
`of 10 is 20dB, a ratio of 100 is 4003, a ratio of 1000 is 60 dB,
`
`unreliable state change at a substation RTU i.e. ..
`‘
`ATMterm. Data 0
`
`etc. For example, if a filter has -40dB of noise reduction, that
`have either gone high or low. They should nomially .
`with an address
`
`
`means that the ratio between the output noise and the input
`: 66. The length 0
`
`ent. An alarm legend is then generated and sent to
`noise is 40dB or 100. The letters “dB" are always used in lower
`. v. country code 2
`with a status of DBI instead of the normal ON or OFF
`case. A 6 dB of loss would mean that there is 6 dB difference
`
`-r) syntax. The cod
`BREAKER 0N
`between what arrives down a communications circuit and what
`
`fight with the hexai
`BREAKER DBI 00
`
`was transmitted by a standard Signal generator. See Decibel.
`>l
`BREAKER OFF
`.ital Compact Ca
`2. Database
`
`t
`i. audio cassette.
`DBI! Also called D-BlT. The delivery confirmation l
`
`3. Short for Data Bus connector. Usually shown with a num—
`i
`X25 packet that is used to indicate whether or not
`analog and dig“
`
`ber that represents the number of wire conductors in the con-
`wishes to receive an end—to—end acknowledgment of n .
`l a lot better.
`
`nector. e.g. 08-9 or DB-25, both of which are very common
`in the X25 packet header that assures
`.. Digital Contri
`in short, a bit
`
`connectors to plug into serial ports on PCs. See DB-Q, DB—15
`integrity between the TPAD and the HPAD.
`-_ digital cellular:
`and 03-25.
`uses between thi
`
`DIM Decibels below 1mW. This should be written as
`db loss Budget Should be written as dB. dB Loss Budget
`station. See alst
`
`Output power of a signal referenced to an input signal of
`is the amount of light available to overcome the attenuation in
`-
`1. Data Carrier
`
`(Milliwatt). Similarly, dBmO refers to output power, exp e
`the optical link and still maintain specifications.
`
`' teri to the DTE
`in dBm, with no input signal. (0 dBM = l milliwalt and
`III-9 This is the standard nine-pin RS—232 serial port on all
`I I m) is receivmg
`
`dBm = 0.001 milliwatt). See Decibel.
`laptop PC computers and most desktop computers today. The
`the other end of it
`DBMS Database management system. A computer prn '
`
`term 03-9 is used to describe both the male and female plug.
`Dynamically Con
`that manages data by providing the services of cent s "
`So be careful when you order. See also the Appendix in this
`,
`.le device is a la
`
`control, data independence, and complex physical stru
`Dictionary for more information on the pinning of RS—232—C
`filled because you
`Advantages include efficient access, integrity, recovery. n
`
`plugs. The above is contemporary usage, i.e. the way it's used
`iistalling one.
`~,
`currency control, privacy, and security. A DBMS enables
`today.
`In fact,
`it's wrong historically. The “D” originally
`ICE 1. Data Comrt
`
`to perform a variety ol operations on data, including retrievi
`described the shape of the housing. The second letter: A, B.
`lion of DCE is the
`appending, editing, updating, and generating reports.
`C, D or E originally specified the size of the housing where the
`Data Terminal Equi
`
`blrn DeciBels above Reference Noise. A ratio of power I ,
`“E" is used somewhat like it’s used as a drawing size (i.e.,
`
`include Network li
`in dB relative to a noise reference. dBrnC uses a noise re ;
`smaller the a “D"). There are connectors made with, e.g.. size
`modems, and rout
`ence of -90 dBm, as measured with a noise meter, weight
`“B" housing with other than 9, 15 or 25 pins. Sometimes coax
`
`as changes in elecl
`by a trequency function known as C-message weighting
`“pins” are included, which use up several little pin locations.
`version. and data t
`which expresses average subjective reaction to interference as
`See the Appendix in this dictionary for more information on
`
`oped by the Eleclt
`a function of frequency.
`the pinning of RS-232 plugs.
`DIS Direct Broadcast Satellite. A term fora satellite which
`DCE devrces (in
`”-1 5 A standardized connector with 15 pins. It can be used
`
`sends relatively powerful signals to small (typically 18-inch
`Equipment) devtcl
`in Ethernet transceivers.
`It can also be used for connecting
`data terminals, or
`
`diameter) dishes installed at homes. See C Band, 1994 and
`VGA monitors. DB-15 is used to describe both the male and
`
`ference between i
`Direct Broadcast Satellite.
`female plug. So be careful when you order. See also DB-Q for
`pins two and thre
`
`DBI! 1. Dial Back-Up. in the event ofthe local leased line fail-
`a longer explanation.
`When wiring one
`
`ing, users are automatically switched to high—speed ISDN
`IDS-25 The standard 25epin connector used for RS-232 ser—
`
`240
`
`5
`
`

`

`-
`
`.
`.
`
`'
`
`.
`
`3
`
`.
`‘
`
`
`
`
`
`NEWTON’S TELECOM DICTIONARY
`
`tion. Because a diode is positive on one side and negative on
`the other. it normally conducts current only in one direction.
`Thus diodes play an indispensable role as rectiliers. That is,
`they can take alternating current (AC) from your wall and con-
`vert it into direct current (DC) to run your computer.
`“In this role, diodes demonstrate a prime law of electrons.
`Negatively charged, electrons flow only toward a positive
`voltage. They cannot flow back against the grain. Like water
`pressure, which impels current only in the direction of the
`pressure, voltage impels electrical current only in the direc-
`tion of the voltage. To attempt to run current against a voltage
`is a little like attaching a gushing hose to a running faucet.
`“It had long been known, however, that it you apply a strong
`enough voltage against the grain of a diode, the p-n wall or
`junction will burst. Under this contrary pressure. or reverse
`bias, the diode will eventually suffer what is called avalanche
`breakdown. Negative electrons will overcome the on barrier by
`brute force of numbers and flood “uphill“ from the positive side
`to the negative side. In erasable programmable read-only mem-
`ories (EPROMs), this eflect is used in programming computer
`chips used to store permanent software, such as the Microsoft
`operating system in your personal computer
`(MS-DOS).
`Avalanche breakdown is also used in Zener diodes to provide a
`stable source of voltage unaffected by changes in current."
`Dioclen A semiconductor device which allows electricity to
`pass through it
`in only one direction. restricting flow the
`other way.
`Diode Mott-ix Ringing A method of connecting a com-
`mon audible line to a system so that all stations do not ring
`on all lines. See also Matrix Ringing.
`DIP 1. The act of consulting a database for information.
`Much like dipping into a bucket of water to extract a drink,
`carrier switches must dip into centralized databases in order
`to access various types of
`information. The database is
`housed in one or more SCPs (Service Control Points), which
`are centralized in the networks in order that many switches
`can share access to them, generally via SST links. Dips are
`made into such databases in order to accomplish tasks like
`calling card verification. 800/800 number routing requires
`that a dip be made in order to determine the serving IXC or
`LEC. LNP (Local Number Portability), mandated by the
`Telecommunications Act of 1996, requires the deployment of
`SCPs in order that the call can be terminated by the sewing
`LEC. See also LNP and Number Portability.
`2. See DlP Switch.
`3. Document Image Processing. A term for converting paper-
`work into electronic images manipulable by a computer.
`Components include input via scanner, storage on optical
`media and output via video display terminal, printer,
`fax.
`micrographics. etc.
`4. See Dedicated Inside Plant,
`DIP Switch Dual In-Line Package. A teeny tiny switch usu-
`ally attached to a printed circuit board. It may peek through an
`opening in a piece of equipment.
`It may not.
`It usually
`requires a ball point pen or small screwdriver to change.
`There are only two settings — on or off. 0r 1 or 0. But print-
`ed circuit boards often have many DIP switches. They’re used
`to configure the board in a semipermanent way. The DIP
`switches are similar to integrated circuit chips which have two
`rows (dual) of pins in a row (in-line) that fit into holes on a
`printed circuit board. If something doesn’t work when you first
`install it. check the DIP switches first. Then check the cable
`connecting it to something else.
`DIP/DDP Dedicated Inside Plant/Dedicated Outside Plant.
`
`260
`
`directly through the ne
`Diphones Speech segment beginning in the middle of .
`central control. The Tel
`phoneme and concluding in the middle of another.
`*
`trol switching. A step
`Phoneme.
`control switching.
`Diplexer A device that permits parallel feeding of
`Direct Current DC
`antenna from two transmitters at the same or different
`direction. Contrast wil
`quencies without the transmitters interfering with each 0
`Direct Current Si
`Diplexers couple transmitter and receiver to the same a i.
`na for use in mobile communications.
`signaling circuit E &
`voice circuit and no i
`Dipole Antenna fed from the center. Name often applied
`“rabbit ear” antenna.
`signals from the vorcr
`DIR An ATM term. This is a field in an RM-cell which i
`Direct Depertrne
`that routes incoming
`cates the direction of the RM-cell with respect to the data ‘
`trunks to specific pht
`with which it is associated. The source sets DIR=0 and
`destination sets DIR=1.
`Direct Distance.
`which lets a user di
`Direct Access Test IInit DATU. Also called Mechan'
`phones outside the u
`Loop Test (MLT) added or built into a central office 3 ‘
`.
`assistance.
`With DATU a technician can execute tests for shorts, 0 >
`Direct Electric-I
`and grounds remotely, The technician gets a digital vi
`between two things.
`enters a password and is given a series of options. Th
`-,.
`two things. This dun
`nician can get results as a digital recording or through
`because there was a
`alpha—numeric pager. DATU units can send a locating tone
`when you couldn’t (i
`TIP, RING or a combination of both. The unit can short Ii
`connect your own ph
`and remove battery voltage for testing.
`network. Those were
`Direct Bond An electrical connection using contin n
`System) were trying ‘
`metal-to-metal contact between the things being joined.
`
`necting anyone else
`Direct Broadcast Satellite DBS. A digital satellite
`»
`
`never did prove this,
`tem transmitting TV programs which can be received by
`nection of FCC—cert
`
`and relatively inexpensive dish antennas typically mounted 1
`won’t cause any hart
`either the roots or sides of houses. The receiving dish is ~~ ..
`Direct In line 8
`
`tionary, being locked in on the position of the DBS
`-,
`'
`.
`Direct In I'erlnii
`provider with which you have a subscription agreement. A:
`programmed to rcu
`,
`result.
`it can receive only those channels broadcast by .
`
`out the attendant int
`specific provider. DBS satellites operate in the Ku-band «I .-
`trunk circuits on a
`
`trum, and at fairly high power levels; hence the small size
`.
`Termination is slig
`the receiving dish, which commonly is as small as 19.7 i
`. ‘
`
`though how differei
`es in diameter. OBS has virtually eliminated the old 0- .
`Direct Interu'l
`
`satellite dishes — huge things about 3 meters (118.1 in
`~ ,
`trunk groups used
`across which you mounted in your back yard. The C r.
`lnterexchange Carr
`
`systems were tunable. however; that is to say that they c
`Presence (POPS) |
`
`be adjusted to pick up programming from just about any
`(300) and Office 5
`broadcast satellite which didn’t encrypt its signals. Once I re:
`”if." 'l‘fl'd
`was introduced in the US. in 1994,
`it very quickly took ~..
`srde a company to
`~
`nificant market share away from the CATV providers.
`9835 through .3“ 0
`Direct Connect A term describing a customer hooki'
`the dialed dlglts 3'
`directly into a long-distance telephone company's switchir'
`office). The PBX th
`office, bypassing the local phone company. Such “direct our-
`is often proposed
`nect" could be via a leased copper pair, a specially-run cop-.
`
`Inward System Ad
`per pair, a tiber optic or a private microwave system. 8‘
`Direct Inward
`
`Direct Electrical Connection, which is different. See Dina!
`
`Connect Modem.
`telephone system
`
`the telephone sys
`Direct Connect Modem A modem connected to tele~
`
`and facilities. DIS
`phone lines using a modular plug or wrred directly to the orfi
`calls from home
`
`side phone line.
`It thus transfers electrical signals directly h
`distance lines, lil
`
`the phone network without any intermediary protective devirx ,
`
`ing dictation for tl
`Direct connect modems must be certified by the FCC. Dire!
`
`vidual extensions
`connect modems are much more reliable and more accum-
`tor. To use DISA
`
`than acoustically coupled modems. Virtually all moderri
`
`phone a short 3,"
`these days are directly connected. One day pay phones wI'
`
`The problem WI“
`lacks into which you can plug tr-
`even come with FtJ-ti
`
`thorrzed 9809'?)
`modem of your portable laptop computer.
`
`run Up expensrve
`Direct Connection Connection of terminal equipmem to
`
`DlSAto trustedp
`the telephone network by means other than acoustic and/or
`generated. Chant
`
`inductive coupling.
`help prevent thi
`Direct Control Switching The switching path is set to
`
`
`6
`
`

`

`NEWTON'S
`
` TELECOM DICTIONARY
`
`
`efinitions (DTDs), often used in relation-
`
`
`. e line. DSVD allows the simultaneous transmis-
`DID DocumentType D
`ship with the Extensible Markup Language (XML). See cXML.
`01'! t. Data Terminal Equipment. in the RS—232—C standard
`., and digitally—encoded voice signals over a single
`
`
`
`specification, the RS—232—C is connected between the DOE
`log phone line. DSVD modems use V34 modula—
`(Data Communications Equipment) and a DTE. The main dif-
`
`
`.
`i 33.6 kilobits per secon ), but may also use v.32
`
`
`,-
`ference between a DCE and a DTE is that pins two and three
`tkilobitsper secondforvoicetransmissions. The
`< ion (14.400 kilobits per second). DSVD modems
`'
`are reversed. See also DOE and the Appendix.
`bandwidth is available for data transmission. The
`'r coder is a modified version of an existing speci-
`2. Defense Technology Enterprise.
`DIE-DC! Rate Data terminal equipment/data communica-
`
`.
`I voice/data multiplexing scheme isan extension
`lions equipment rate. A designation for the maximum rate at
`i is defined as (3.729 Annex
`' error correction protocol widely used in modems
`which a modem and a PC can exchange information.
`
`I also specifies tallbacks that enable DSVD
`expressed in kilobits per second (kbps). For maximum per—
`~
`
`communicated with standard data modems (Le.
`formance, a modem must support a DTE—DCE rate in excess
`
`‘ bis. v.32 and v.22).
`of its maximum theoretical throughput,
`
`You Do With DSVD? (Below is good manufacturer
`Dterm A line of proprietary electronic phones madeby NEC
`
`on DSVD. The words came from Rockwell.)
`for use with its PBXs. The Dterm terminal derives its intelli-
`uerpromised someoneonthetelephonethatyou’d
`gencefrom its own microprocessor. which detects events and
`
`i
`-.
`to them, then forget to send it? Have you ever
`accepts direction from the PBX.
`
`a replacement for C-band
`country or halfway around the world to make a
`D'I'Il Direct To Home. intended as
`
`o operate on medium-
`satellite systems, DTH was proposed l
`
`. e and applications as away to communicate?
`powered FSS (Fixed Satellite Systems) in the Ku—band. DTH
`.
`~ ? Have you considered expensive video confer-
`
`was superseded by DBS (Direct Broadcast Satellite). which
`.
`.
`allows the use of even smaller receive antennaethan possrble
`“skated wailing online, hoping to get some tech-
`
`‘ needto work on a project. spreadsheet or presen—
`with DTH. See also Direct Broadcast Satellite and KU Band.
`
`someone from another location, a DSVD modem MI.An ATMterm. Designated TransitList: Alistofnodesand
`optional link le that completely specify a path across a sin-
`r oftice or requiring costly
`, i without leaving you
`
`.
`-.
`ing equipment. Both parties can simultane
`gle PNNl peer group
`«i we on a shared document, each viewing and Ml Originator An ATM term. The first switching system
`within the entire PNNl routing domain to build the initial DTL
`
`the additions and modifications made. This can
`aid money previously wasted exchanging faxes
`stack tor a given connection.
`
`on overnight express mail deliveries. Computer
`It'l'l. Terminator An ATM term. The last switching system
`
`demonstrations can be easilyconducted through
`within the entire PNNl routing domain to process the connec—
`to highlight or test mar-
`tion and thus the connections DT .
`
`mu Digital Trunk and Line Unit. Provides system access
`. This is a great way
`. >
`
`inter office trunks or remote
`« and get immediate customer feedback. For
`for Ti—carrier
`lines used for
`
`company. DSVD means fewer support follow-up
`- telephone bills. With aDSVD modem. you will
`switching module umbilicals.netinsightse, DTM (Dynamic syn—
`
`dial your
`favorite online catalog showrooms.
`DTM According to w.‘s a network protocol for high speed
`isles. ask a salesperson a question or two. then
`chrohous Transfer Mode)i
`
`. Unlike other online "malls". with DSVD the
`networking developedfordynamictransportof integratedtraf-
`. r isstill intact.While you‘re interactively shop-
`tie.
`it
`is a transport network architecture based on circurt-
`
`- Hitwith salespeople or even other shoppers.
`switchingaugmentedwith dynamicreallocation of bandwidth.
`
`ulna“. SeeVJO.
`The protocol
`is designed to be used in integrated services
`
`Crossconnect frame. it is a manual bay
`networks, it supports point—to—point. multicast and broadcast
`.. T—t lines and 031 circuit packs are wired.
`communication. is. a DTM networkwill be used for both dis—
`
`. moss—connections by patch cords and plugs.
`tribution and unicast communication. DTM includes switch—
`
`ing and a signaling protocol and can thus. in contrast to say
`
`SDH/SONET, set up multi—rate channels (circuits) on demand.
`'
`, ADSX panel is used in small office applications
`
`and the capacity of a channel can be changed according to
`h digital trunks are installed. See also DACS.
`
`during
`operation. Additionally.
`Sight Cross-connect Level 1. The set of para—
`tralfic
`characteristicscaled between nodes according to the
`
`._ extracting DS-t lines.
`
`s, c n for the 033 point of interface (cross-
`resources can be reallo
`current demands. in this way, tree bandwidth is allocated to
`
`nodes with highest demands, providing an autonomous and
`'i- r.
`01 allows long distance carriers to‘
`erm describing
`efficient dynamic infrastructure.
`Illuminate the switched traffic over dedi—Dtrect
`.
`'
`DTM! Dual Tone Multi—Frequency. A fancy t
`
`‘
`htone dialing. (Touchtone is a not regis—
`‘. 1- was to the customer premises.
`f » Brand usingsix orten-digit screening in
`push button or Touc
`
`4* mmswitch.
`teredtrademark01 AT&T.though until 1934 itwas.) In DTMF.
`
`‘ “Muller.
`when you touch a button on a push button pad,
`it makes a
`
`. Calm
`tone. actually a combination of two tones. one high frequen—
`and. A digital cellular term. Defined in
`cy and one low frequency. Thus the name Dual Tone Multi
`
`. aportim ofthe air interfacewhich car-
`Frequency, in US telephony. there are actually two types of
`muddle DTC operates over ire
`“tone" signaling, one used on normal business or home
`ushbutton/touchtone phones, and one used for signaling
`i;
`ll: DCCH (Digital Control CHannel),
`p
`_ yin aid comm purposes. See also
`within thetelephone network itself. When you go into a cen-
`
`:
`tral office, lookfor thetest board. There you‘ll see what looks
`60’)
`7
`
`‘
`
`7
`
`

`

`NEWTON'S TELECOM DICTIONARY
`The first personal computer Ethernet LAN adapte
`t r Was
`shipped by 3Com on September 29, 1982 usin
`Ethernet silicon from SEEO Technology. Bob Metca~fe he first
`the original Ethernet specification at Xerox PARC an~ertect
`ater
`went on to found 3Com. In the October 31, 1994 issue
`magazine lnfoWorld, Bob Metcalfe explained that Ethern °/ lhe
`its name "when I was writing a memo at the Xerox Pai e Qot
`Research Center on May 22, 1973. Until then I had beei Alto
`ing our proposed multimegabit LAN the Alto Aloha Ne can(cid:173)
`The purpose of the Alto Aloha Network was to connect :ork.
`imen_tal personal compu_ters called Altos .. And it used ~er(cid:173)
`dom1zed retransm1ss1on ideas from the University of Haw a~(cid:173)
`Aloha System packet radio network, circa 1970. The aii s
`the omnipresent word
`ether came from luminilerous ether -
`sive medium once theorized to carry electromagnetic /as(cid:173)
`through space, in particular, light from the Sun to the E:~~s
`Arou_nd the time of Einsteins Theory_ of Relativity, the light~
`in namin 0
`bearing ether was proven not to exist. So,
`LAN's omnipresent passive medium, then a coaxial ~ablur
`which would propagate electromagnetic waves, namely dar·
`a
`packets, I chose to recycle ether. Hence, Ethernet."
`According to Metcalfe, "Ethernet has been renamed repeated(cid:173)
`ly since 1973. In 1976, when Xerox began turning Etherne
`into a product a_t 20 million bits per second (Mbps), we calleci
`1t The Xerox Wire. When D1g1tal, Intel, and Xerox decided in
`1979 to make it a LAN standard at 10 Mbps, they went back
`to Ethernet. IEEE tried calling its Ethernet standard 802 3
`carrier sense multiple access with collision
`CSMA/CD -
`detection. And as the 802.3 standard evolved, it picked u
`such names as Thick Ethernet (IEEE 10Base-5), Thin Ethern~
`(10Base-2), Twisted Ethernet (10Base-T), and now Fast
`Ethernet (1 OOBase-T)."
`Ethernet PC cards now come in a couple of basic varieties(cid:173)
`for connecting to an Ethernet LAN via coaxial cable or via two
`twisied pairs of phone wires, called 10Base-T. See also
`10Base-T, Collision Domain, Ethernet Controller, Ethernet
`Identification Number, Ethernet Switch, Ethertalk, Frame
`'
`Thinnet and Token Ring.
`Ethernet Controller The unit that connects a device to
`the Ethernet cable. An Ethernet controller typically consists of
`part of the physical layer and much or all of the data link layer
`and the appropriate electronics.
`Ethernet Identification Humber This is a unique,
`hexadecimal Ethernet number that identifies a device, such as
`a PC/AT with a Speedlink/PC16 network interlace card
`installed, on an Ethernet network.
`Hhernet II (DIX) Defined by Digital, Intel and Xerox. The
`frame format for Ethernet II differs from that of IEEE 802.3 in that
`the header specifies a packet type instead of the packet length.
`Ethernet Switch An Ethernet data switch. Ethernet is the
`most common local area network (LAN) standard in the world
`today. Ethernet is very cheap, but its