Electronic Mall-Ephemeris

Electronic Mall

A virtual shopping mall where you can browse and buy products and services online.

Electronic Message Registration

A system to detect and count a phone user 's completed local calls and then tell the central office the number of message units used. Also used in hotels.

Electronic Messaging Association

EMA. The trade association for electronic messaging and information exchange. Formerly known as the Electronic Mail Association, EMA is a membership forum that seeks to enable users to work in partnership with providers of the technologies. Vendor members offer a wide range of services, including electronic mail, network, directories, computer facsimile , electronic data interchange (EDI), paging, groupware, and voice mail. EMAs technology programs aim to remove barriers to global interconnectivity and interoperability through assisting in the definition, endorsement, development, demonstration, and implementation of all messaging standards, operating conventions, and practices for use in electronic commerce. EMA lobbies governments , standards bodies, and consumer groups in advocacy of favorable public policies. www.ema.org.

Electronic Order Exchange

EOE. Inter-company transactions between buyers and sellers handled electronically via standard data communications protocols. EOE can be employed to send purchase orders, price and product listings and order- related information.

Electronic Perception

Electronic perception is a method of bringing primitive 3D vision to a variety of less expensive devices. The approach uses infrared light and a sensor chip like those in digital cameras . Light is beamed at the target, and the tiny differences in the time it takes rays to return to specific points on the chip are measured. Gauging distance based on the time that signals travel to and from a target is the principle behind radar. Electronic perception uses the time differences to compute a three-dimensional relief map of the target.

Electronic Phone

General description for most phones designed after about 1980, where many mechanical and electrical parts are replaced by smaller, lighter, and cheaper electronic parts. Features such as mute, redial and memory became popular with these phones, which range in price from $5 to hundreds of dollars.

Electronic Product Code

EPC. A 96-bit code, created by the Auto-ID Center, that will one day replace barcodes. The EPC has digits to identify the manufacturer, product category and the individual item. It is backed by the United Code Council and EAN International, the two main bodies that oversee barcode standards. See also Auto ID Center.

Electronic Publishing

Electronic Publishing is synonymous with Desktop Publishing. Electronic Publishing software packages give the user the ability to perform page composition, insert images and manipulate text on the computer screen and display the document on the screen exactly as it will look when it is printed.

Electronic Receptionist

A fancy name for a voice processing automated attendant, except that in addition to all the normal auto attendant features, it also sends messages to personal PCs on LANs telling the owner who's calling and giving the owner (the called party) the choice of doing something with the call ” like answering it or putting it into voice mail.

Electronic Redlining

A term for disenfranchising people and institutions because of their lack of telecommunications services and apparatus. In December, 1993, Vice President of the United States, Al Gore, told the National Press Club, When it comes to ensuring universal service, our schools are the most impoverished institution in society. Only 14% of our public schools used educational networks in even one classroom last year. Only 22% possess even one modem. Video-on-demand will be a great thing. It will be a far greater thing to demand that our efforts give every child access to the educational riches we have in such abundance . The recent article in the Washington Post on the proposed video communication network in the D.C. area is a wake-up call to all of us concerned about "electronic redlining."

Electronic Ringer

A substitute for the conventional telephone bell, that uses music synthesizer circuitry to generate an attention-getting signal played through a speaker. Typical sounds include warbles, chirps, beeps, squawks, and chimes. The writer of this entry, Michael Marcus, once installed a phone with a chirp sound. A few days later, the customer complained that she had not been receiving any calls, and the birds in her yard were chirping much more than usual.

Electronic Serial Number

ESN. A 32-bit binary number which uniquely identifies each cellular phone. The ESN consists of three parts: the manufacturer code, a reserved area, and a manufacturer-assigned serial number. The ESN, which represents the terminal, is hard-coded, fixed and supposedly cannot be changed. Paired with a MIN (Mobile Identification Number), the ESN and MIN are automatically transmitted to the mobile base station every time a cellular call is placed. The Mobile Telephone Switching office checks the ESN/MIN to make sure the pair are valid, that the phone has not been reported stolen, that the user's monthly bill has been paid, etc., before permitting the call to go through. At least that's the theory. It doesn't always work this way on calls made from roaming cellular phones. And some cellular phones have been known to have their ESNs tampered with (it's called fraud) which tends to mess up the billing mechanisms. See MIN.

Electronic Signature Act

Also known as the E-Sign Act, the Electronic Signatures in Global and National Commerce Act took effect on October 1, 2000. The Act defines an electronic signature as "an electronic sound, symbol or process, attached to or logically associated with a contract or other record and executed or adopted by a person with the intent to sign the record." (I'll bet you my next paycheck that a whole gaggle of attorneys wrote that definition.) The Act provides that no contract, signature, or record shall be denied legal effect solely because it is in electronic form. It also provides that most electronic contracts and records are legally enforceable only if they are in a form that is capable of being retained and accurately reproduced for later reference by relevant parties. The Act will go a long way towards ensuring the viability of E-commerce, since electronic signatures now have the same effect as do paper and wet ink contracts. Any requirement that a stamp, seal, or other embossing device be used to authenticate a signature of document is eliminated. The Act will also speed up the contractual process, as documents can be sent electronically over the Internet, rather than by fax, courier, and postal service. The Act applies equally to transactions in interstate and foreign commerce. However, the Act does not apply to contracts or records relating to wills, adoption, divorce, or other family law matters; much of the Uniform Commercial Code (UCC); court orders; notices of cancellation of utility services; recall notices for products endangering health or public safety; and a whole host of other such things.

Electronic Sweep

Variation in the frequency of a signal over a whole band as a means of checking the response of equipment under the test.

Electronic Switching System

A telephone switch which uses electronics or computers to control the switching of calls, their billing and other functions. The term is now vaguely defined, with each manufacturer defining it as something somewhat different. In fact, every telephone switch sold today is electronic. The term originally came about because early telephone switches were entirely electro-mechanical. The switch consisted entirely of a moving switch. Devices like relays physically moved in order to send the call through the exchange and on its way. These things moved in direct response to the digits dialed by the telephone subscriber. These switches contained no "intelligence" ” i.e. no ability to deviate from a set number of very simple tasks which could be accomplished by electromechanical relays.

Then someone said: it would be more efficient if the "instruction part" of the process were divorced the switching mechanism. This lead to the creation of the "electronic" switch in which the "brains" of the switch are separated from the switching mechanism itself. Thus the "brains" can do simple things like collect the dialed digits as they are slowly dialed and pulse them out quickly to the switch ” as fast as it can handle them. Now, the " brains " are typically a digital computer.

Electronic Tandem Network

  1. Two or more switching systems operating in parallel as part of providing network services (usually voice) to large users.

  2. A telephone company switching device used to connect telephone company toll offices located in the same geographic area.

Electronic Telephone Directory Service

A PBX feature which stores and produces, on demand, a directory of all extension phone numbers. The directory may include all users in a network. A CRT with keyboard and/or printer is usually required for input and retrieval. In some systems, the CRT or another type of alphanumeric display is part of the Attendant Console. In some systems, the directory may also include names and telephone numbers of frequently called outside people, especially those in the speed calling system. The directory may also be enhanced to include SMDR data such as client codes, account codes and client telephone numbers .

Electronic Text Mail

A "Store and Forward" service for the transmission of textual messages transmitted in machine readable form from a computer terminal or computer system. A message sent from one computer user to another is stored in the recipient's "mailbox" until that person next logs onto the system. The system then can deliver the message. Telex, in which a machine readable form of message transmission takes place, is also considered an Electronic Text Mail medium, albeit a very slow one. For an example of electronic mail, please dial our electronic mail system on 212-989-4675. It's free. Parameters are 300, 1200 or 2400 baud, 8 data bits, one stop bit, and no parity.

Electronic Voice Mail

A system which stores messages usually spoken over a telephone. These messages can be retrieved by the intended recipient when that person next calls into the system. Also called Voice Mail, it operates just like a touch-tone controlled answering machine.

Electronic Wallet

See Digital Wallet.

Electronic Warfare

See EW.

Electrophotographic Printing

A printing method that uses light to modify electrostatic charges on a photoconductive substrate.

Electrostatic Charge

An electric charge at rest.

Electrostatic Discharge

ESD. Let's say you;re a maker of components that go into a cell phone., also called a wireless or mobile phone. Every time someone picks the phone to use it, they transfer a static electricity charge to the phone. Think what happens when you walk across a nylon carpet in the winter and go to shake someone's hand. A spark flies. You get a shock. Well, you're giving your phone also a shock . Though you mightn't feel it, your phone sure does. If the components don't have good ESD, they will get damaged and your phone will no longer work. All this is why manufacturers talk a lot about their ESD and how good their components are in resisting and dissipating static electricity charges. It's clearly important. ESD's formal definition is "Discharge of a static charge on a surface or body through a conductive path to ground. Can be damaging to integrated circuits."

Electrostatic Printing

A method of printing, very common in photocopying, in which charges are beamed onto the surface of paper. The charges attract particles of a very fine (typically black powder) which sticks to the charges. The black powder is fused permanently on the paper by great heat. "XEROXing" is electrostatic printing. In xeroxing, the black powder is called toner.


An elegant program is one that is efficiently written to use the smallest possible amount of main memory and the fewest instructions.


A Russian phone company.


  1. Any single piece of data. For example, a user name is an element of a login string, and a BORI is an element of a header field.

  2. Network Element (NE). A constituent part of a network. An element might be in the form of a modem, a multiplexer, a switch, or some other basic unit of a network.

  3. The structural building blocks of HTML documents. Blocks of text in HTML documents are contained in elements, according to their function in the document, for example, headings, lists, paragraphs of text and links are all surrounded by specific elements. See HTML.

  4. An XML element contains data that is transferred between a client and a server, or between two servers. See also XML.

Element Management Layer

See EML.

Elevation Beam Width

The vertical measure (usually in degrees) of an antenna pattern.

Elevator Eyes

A term used in sexual harassment to mean viewing someone up and down.

Elevator Pitch

You're selling someone on your ideas. They only want to hear a summary. They ask you for an "elevator pitch" ” i.e. presentation that last no more than an elevator ride. Clearly, that's too short. They're willing to listen for five to ten minutes, but no more.

Elevator Seeking

Organizes the way data is read from hard disks and logically organizes disk operations as they arrive at the Novell NetWare local area network server for processing. A queue is maintained for each disk driver operating within the server. As disk read and write requests are queued for a specific drive, the operating system sorts incoming requests into a priority based on the drive's current head position. As the disk driver services the queue, subsequent requests are located either in the vicinity of the last request or in the opposite direction. Thus, the drive heads operate in a sweeping fashion, from the outside to the inside of the disk. Elevator seeking improves disk channel performance by significantly reducing disk head thrashing (rapid back-and-forth movements of the disk head) and by minimizing head seek times. Imagine how inefficient an elevator would be if the people using it had to get off the elevator in the order they got on.


Extremely Low Frequency. Frequencies from 30 Hz to 300 Hz.


Equal Level Far End Crosstalk. Not a measurement, but a calculated result, that is derived by subtracting the insertion loss of the disturbing pair from the FEXT this pair induces in an adjacent pair. See PESELFELT.


Electrical Line Interface Unit.

Elliptic Curve

Elliptic curves are created using mathematical expressions from number theory and algebraic geometry. Elliptic curve cryptosystems replace conventional modular discrete logarithm cryptosystems with the elliptic curve operations. There are currently no specialized attacks, which means that shorter key sizes for elliptic cryptosystems give the same security as larger keys in other cryptosystems.

Elite hacker

One of a reasonably small number of hackers who possess great skill and imagination , Elite hackers are able to devise novel attacks which are technically sophisticated and ingenious.


The fractional increase in length of a material stressed in tension.


Hellenic Organization for Standardization (Greece).


Ethernet LAN Service Unit. An ELSU provides 12 independent virtual Ethernet bridges for running over ATM networks. ELSUs are designed for flexible deployment, either local to an ATM switch or at a remote site. ELSUs are designed for LAN internetworking services over ATM networks.

Elvis Year

The peak year of something's popularity.


  1. Element Manager. Software and hardware used to manage and monitor components of a telecommunications network at their lowest level.

  2. Abbreviation for End of Medium. The binary code is 1001001, the Hex is 91.

  3. Electromagnetic. See Electromagnetic Spectrum.


See Electronic Messaging Association.


A standard Unix text editor preferred by Unix types that beginners tend to hate.


ETSI MIS Advisory Group .


A colloquial term for electronic mail. See Email address.

Email Address

The UUCP or domain-based address by which a user is referred to. My email address is HARRYNEWTON@MCIMAIL.COM.

Email Gateway

An email gateway is typically a PC on LAN. The PC has one or more modem and/or fax/modem cards. Its job is to send and receive e- mails and/or send and receive faxes for everyone on the LAN. To pick up emails, it might dial once an hour into various mail systems, like MCI Mail, CompuServe, and download all the messages for all the people on the LAN. Once it has those messages, it brings them onto its hard disk and then alerts the recipients that they now have an e-mail. See Server.

Email Hygiene

Principles or practices that reduce spam and protect a computer from viruses and other threats embedded in or attached to e-mail messages.

Email Reflector

An Internet electronic mail address which automatically sends you back a reply (i.e. reflects mail to you) if you include certain key words in your message to it. Such key words might be "subscribe" or "lists help."

Email Server

See Email Gateway.

Email Shorthand

Acronyms for commonly used phrases that one would otherwise type. Some of the most popular ones are: IMHO: In My Humble Opinion; BTW: By The Way; RTM: Read The Manual; LOL: Laughing Out Loud; FWIW: For What It's Worth; and ROFL: Rolling On The Floor Laughing.

Email Threads

A fancy way of saying on-going correspondence by electronic mail. I first heard this term from Sean Purcell, a smart fellow working on the excellent product called Outlook from Microsoft.


Motorola's company which does wireless electronic mail to people carrying laptops and palmtops. EMBARC, according to Motorola, stands for Electronic Mail Broadcast to A Roaming Computer. Actually EMBARC does more than mail. It also broadcasts snippets of news.


To make something an integral part of some larger, like a fossilized insect is embedded in a rock. In our context, one example is to insert information (an object) that was created in one document into another document (most often the two documents were created with different applications). The embedded object can be edited directly from within the document. To embed under Windows 3.1, you must be using applications that support OLE (Object Linking and Embedding). Another example is to embed a network interface card in a laptop.

Embedded Base Equipment

All customer-premises equipment that has been provided by the Bell Operating Companies (BOCs) prior to January 1, 1984, that was ordered transferred from the BOCs to AT&T by court order.

Embedded Code Formatting

ECF. A NetWare definition. This is something of a programming language, in which faxing commands or other program that automatically generates information, formats it, and faxes it without user intervention.

Embedded Customer-Premises Equipment

Telephone-company- provided premises equipment in use or in inventory of a regulated telephone utility as at December 31, 1983.

Embedded Hyperlink

A hyperlink that is in a line of text. A hotspot is the place in a document that contains an embedded hyperlink.

Embedded Network Interface

See ENI.

Embedded Object

A Windows term. An embedded object is information in a document that is a copy of information created in another application. By choosing an embedded object, you can start the application that was used to create it, while remaining in the document you're working in.

Embedded Operations Channel

See EOC.

Embedded SCSI

A hard disk that has a SCSI (Small Computer System Interface) and a hard disk controller built into the hard disk unit. See also SCSI.

Embedded SQL

SQL statements embedded within a source program and prepared before the program is executed.

Embedded System

An embedded system is a combination of computer hardware and software, either fixed in capability or programmable; that is specifically designed for a particular kind of application device. Industrial machines, automobiles, medical equipment, cameras, household appliances, airplanes, vending machines, and toys (as well as cellular phones and PDAs) are among the possible hosts of an embedded system. Embedded systems that are programmable are provided with a programming interface. Some operating systems or language platforms are tailored for the embedded market; however, some lowend consumer products use inexpensive microprocessors and limited storage. In these devices, the application and operating system are both part of a single program written permanently into the system's memory, rather than being loaded into RAM and changeable by the user. See Embedded Windows.

Embedded System Processors

National Semiconductor's line of high-performance microprocessors used in dedicated systems, such as fax machines and laser printers.

Embedded Windows

When you start your PC you have to wait while it loads Windows operating system off its hard disk into memory and configures itself to start accepting your humble commands. This process is known as bootup . Imagine a device which has Windows OS built into it, so that Windows pops up ready to go immediately when you switch it on. Developers increasingly use the embedded version of Microsoft's Windows in devices such as cell phones, PDAs, industrial machines, automobiles, medical equipment, cameras, household appliances, airplanes, vending machines, and even toys. The rationale is that the devices embedded with the Windows operating system have a familiar feel, as well as compatibility with PCs. Microsoft began pursuing small embedded systems in 1996 with its release of Windows CE 1.0, a from-scratch code base targeting handheld device applications with a graphical interface (GUI) that had the look and feel of Windows 95. Embedded devices have shifted from using relatively simple 8-bit processors to faster and more powerful 16 and 32-bit units as users' wanted their gadgets to be more like their PCs. See Embedded System and Palm.


A means of marker identification by thermal indentation leaving raised lettering on a cable's sheath material.


ElectroMagnetic Compatibility.


Electromagnetic Energy.


Europe, Middle East, and Africa.

Emergency Access

An alarm system built into some PBXs. In an emergency it rings all phones.

Emergency Alert System

See Emergency Broadcast System and EAS.

Emergency Broadcast System

EBS. The EBS is composed of AM, FM, and TV broadcast stations; low-power TV stations ; and non-Government industry entities operating on a voluntary, organized basis during emergencies at national, state, or operational (local) area levels. "This is a test of the Emergency Broadcast System ” this is only a test." That warning, a remnant of the cold war, is about to disappear. The high-pitched tone is to be replaced by a few short buzzes, and the "this is a test" warning may be dropped altogether. The buzzes are generated by new computer technology. The new system, approved by the FCC in 1994, is expected to be fully operational by 1998 as the Emergency Alert System. The current test lasts ca. 35 or 40 seconds; the new test will be shorter, although the duration is not yet decided upon. The system has never been used for a nuclear emergency, but is used regularly for civil emergencies and severe weather alerts. The current emergency broadcast system is serial, that is it works on a daisy chain where one station receives the warning and sends it on to the next. That means that, if one station's equipment fails, the warning may not get further down the line. The new system looks more like a 'web' in which a station does not rely on one sole source for the signal, but will receive digital signals that will activate computers at broadcast facilities and download emergency messages.

Emergency Dialing

A variation on speed calling to call numbers for police, fire department, ambulance, etc. Typically found as special buttons on an electronic phone.

Emergency Hold

"Emergi-hold" allows a 911 caller's line to be held open in the event that a caller attempts to hang up. This gives the PSAP (Public Service Answering Position) agent full control of the call. It will not be released until the agent finishes the call.

Emergency Power

A stand-alone secondary electrical supply source not dependent upon the primary electrical source.

Emergency Ringback

This feature enables the 911 PSAP (Public Service Answering Position) attendant to signal a caller who has either hung up or left the phone off hook. Emergency Ringback enables the PSAP agent to ring a phone which has been hung up or issue a loud "howling" sound from the customer's phone if it has been left off hook.

Emergency Service Number

ESN. In the US emergency services telephone network, a three to five digit number used to represent an Emergency Service Zone. The ESN is used for 9-1-1 call routing to and between public safety answering points. The ESN for each call is derived from the call's Automatic Location Identification. See ESN.

Emergency Service Zone

ESZ. In the US emergency services telephone network, a geographic area served by a single public safety answering point (PSAP). Each ESZ contains a unique combination of emergency service agencies (police, fire, medical); multiple ESZs may be served by one PSAP. Each ESZ is represented by a unique Emergency Service Number.

Emergency Stand Alone Service

A feature of a central office switch which allows it to keep working ” switching and transferring calls ” even though some of its connections to other central offices switches have been broken.

Emergency Telephone

A single line telephone that becomes active when there is no commercial AC power to the Key Service Unit.


ElectroMotive Force, or ElectroMagnetic Force, a synonym for voltage. See also Ohm's Law and Voltage.


  1. Electromagnetic Interference, (EMI) happens when one device leaks so much energy that it adversely affects the operation of another device. EMI is reduced by copper shielding. National and international regulatory agencies (FCC, CISPR, etc.) set limits for these emissions. Class A is for industrial use and Class B is for residential use.

    Here's a definition from APC: EMI usually refers to unwanted electrical noise present on a power line. This noise may "leak" from the power lines and affect equipment that is not even connected to the power line. Such "leakage" is called a magnetic field. Magnetic fields are formed when unwanted noise voltages give rise to noise currents. Such noise signals may adversely affect electronic equipment and cause intermittent data problems. EMI protection is provided by noise filters placed on the AC power line. The filter reduces the noise voltage on the protected line, and by doing so also eliminates the magnetic fields of noise generated by the protected line. Noise signals that act over a significant distance are called RFI (Radio Frequency Interference). Equipment power cords and building wiring often act as antennas to receive RFI and convert it to EMI.

  2. Exchange Message Interface.

EMI Segregation

Isolation of the telecommunications signal from electromagnetic interference.


See Exchange Message Interface/Exchange Message Record.

EMI/RFI Filter

A circuit or device containing series inductive (load bearing) and parallel capacitive (non-load bearing ) components, which provide a low impedance path for high-frequency noise around a protected circuit.


  1. Electromagnetic energy propagated from a source by radiation or conduction. The energy thus propagated may be either desired or undesired and may occur anywhere in the electromagnetic spectrum.

  2. Radiation produced, or the production of radiation, by a radio transmitting station. For example, the energy radiated by the local oscillator of a radio receiver would not be an emission but a radiation.


Ratio of flux radiated by a substance to the flux radiated by black body at the same temperature. Emissivity is usually a function of wavelength.


The source of optical power.


  1. Element Management Layer. A layer representing the management and monitoring of components, at their lowest level, in a telecommunications network. In short, an abstraction of the functions provided by systems that manage each network element on an individual basis.

  2. Expected Measured Loss.


Entitlement Management Message Stream. Entitlement Management Messages define access rights for each individual decoder. The EMM stream is processed with the access control device, but the user processor is responsible for buffering EMMs and feeding them via an interface to the access control device.


Mock HTML tags (<smile>, <smirk>) used in WWW-related e-mail and newsgroups in place of ASCII emoticons, for example: "<flames> Someone tell that jerk to shut up, I'm sick of his vapid whining! </flame>." Definition from Wired Magazine. See Emoticon.


From Emotional Icon, one of a growing number of typographical cartoons used on BBSs (Bulletin Board Systems) to portray the mood of the sender, or indicate physical appearance. They are meant to be looked at sideways . Some examples:

:-D writer talks too much

:-# writer's lips are sealed

:-o writer is surprised

:-& writer is tongue-tied

ALL CAPS writer is shouting

:) is a smiley face

;) is a smile with a wink

;( is a frown with a wink

(:( is very sad

;? is a bad guy

[:0 is a wide-open mouth and a crewcut

(:{>X is bald with a handlebar mustache and bow tie

:- is Wayne Newton

{8<)# is Michael Marcus, the writer of this entry: balding, glasses , mustache, smiling, beard.

Here's another collection of emoticons which I found on the Internet:

:-) Smile                                                        :-D Laughing

:) Smile                                                        :-} Grin

:-] Smirk                                                      :-( Frown

;-) Wink                                                        :-X Close-mouthed

8-) Wide-eyed                                    :-O Open-mouthed

:-) I wear a moustache        :-Q But I don't inhale

                                                                               :-o Oh, no!

<g> Grin

<ggg> Wide Grin

<g....g> Very wide grin

See also Smiley Face.


A large and fast-moving electromagnetic pulse caused by lightning.


In FM transmission, the intentional alteration of the amplitude-versus-frequency characteristics of the signal to reduce adverse effects of noise in a communication system. The higher frequency signals are emphasized to produce a more equal modulation index for the transmitted frequency spectrum, and therefore a better signal-to-noise ratio for the entire frequency range.

Employee Tailgating

You check into your company with your ID badge. Because you're chivalrous you hold the door open for the employee following you, who thus doesn't have to slide his ID badge through the system. This is called tailgating. Most companies frown on it.


EmPower is a standard for a plug which many airlines have adopted to allow their fyers adapter for aircraft. EmPowerT is the number one choice of airlines around the world. Adopted by almost 40 airlines, there are over 86,000 seats on almost 1600 aircraft using this system.

Empty Slot Ring

In LAN technology an empty slot ring is a ring LAN in which a free packet circulates through every workstation. A bit in the packet's header indicates whether it contains any messages for the workstation. If it contains messages, it also contains source and destination addresses.

Empty Suit

You don't need to pass an IQ test to buy a suit. Dumb executives who wear nice suits are often called "empty suits" around telephone companies, especially by craft workers who never wear suits , except to funerals, marriages and bar mitzvahs. See Suit.


  1. Exchange Message Record. Bellcore standard format of messages used for the interchange of telecommunications message information among telephone companies. Telephone companies use EMR to exchange billable, non-billable, sample, settlement and study data. EMR formatted data is provided to all interdepartmental applications and to large customers (users) who request reproduced message records for control and allocation of their communication costs. Bellcore BR-010-200-010 Issue 15, Oct 96. In November of 1998, I heard that EMR was being replaced by something called EMI so that it applies to IXCs as well as LECs.

  2. Electromagnetic Radiation.


  1. Enterprise Messaging Server. A Microsoft concept which allows users to transparently access the messaging engine from within desktop applications to route messages, share files, or retrieve reference data. According to Microsoft, corporate developers will be able to add capabilities using Visual Basic and access EMS by writing either to the X.400 Application Program Interface Association's (XAPIA's) Common Mail Calls (CMC) or to Microsoft's Messaging API (MAPI). See MAPI.

  2. Electronics Manufacturing Services. A fancy name for outsourcing.


Electrical Metal Tubing. In many towns you must run your electrical AC wire inside metal tubing. In other towns you can run normal plastic insulated wiring. Theoretically, EMT is a safer fire hazard . What you are allowed to run depends on local laws and regulations. Tip: Dimmers for incandescent lights raise havoc with LAN data. Solution: Put the plastic electrical wires inside EMT (Electrical Metal Tubing) and ground the conduit.


To duplicate one system or network element with another. For instance, to imitate a computer or computer operating system by a combination of hardware and software that allows programs written for one computer or terminal to run on another. For example, at one stage the most common data terminal was a DEC VT-100. Our communications program, Crosstalk, allowed us to "emulate" a DEC-VT100 on our IBM PCs and PC clones . At another stage several companies were trying to write "emulator" software which would allow software written for Windows to successfully run on a computer running the Linus operating system. There are also emulator programs which allow Windows software to run on Apple machines. Emulator programs usually extract their toll in a loss of efficiency versus running the software directly in "native implementation," i.e. running the software on the operating system it was originally written for.

Circuit emulation, an ATM term, refers to the ability of an ATM network to emulate a circuit over a channel in a T-carrier electrical environment or the over a Virtual Channel in a SONET/SDH fiber optic transmission system. LANE (LAN Emulation) allows an ATM network to emulate a LAN, offering LAN functionality over an ATM network. See LANE for more detail.


What happens one gadget emulates another. See Emulate.

Emulation Mode

Function of a network control point (NCP) that enables it to perform activities equivalent to those performed by a transmission control unit. See NCP.


A device or computer program which can act as if it is a different device or program, that is Emulate (i.e. pretend to be) another device. Certain computer terminals are necessary in specific systems and a terminal that is not that type may be able to act as if it was. If it can, it is an Emulator. This is not a common term. See also the verb Emulate.

En bloc

See En-bloc.


Enbloc is considered a buffer that holds on to all dialed digits and sends all digits to the central office at the same time. This must be enabled for PRI. It is an ISDN term for a process of call establishment. En-bloc (from French, meaning "in a group") places all of the necessary information in a block of data which is part of the call setup message sent to the network in order to request the establishment of a connection. Such information includes originating number, dialed number, and type of call (e.g., voice, data, or video). En-bloc is used in ISDN PRI (Primary Rate Interface) implementations, as the device (e.g., PBX or router) is sophisticated enough to implement this approach. It also is used in BRI (Basic Rate Interface) implementations , assuming that an intelligent TA (Terminal Adapter) or ISDN router is involved. En-bloc signaling is highly efficient in comparison to "overlap sending," where each dialed digit is sent individually, as it is dialed. The most common example of en-bloc dialing is what we do when we dial on a cell phone. We punch out our digits. They stay in the phone until we hit "Send." The phone then sends our complete dial stream into the network. En-bloc dialing at its best. See also En-bloc signaling.

En-bloc Signaling

Signaling in which address digits are transmitted in one or more blocks, each block containing sufficient address information to enable switching centers to carry out progressive onward routing. See en-bloc.


A European test standard for UPS system safety. Supercedes and is a superset of the IEC950 standard formerly used for UPS testing. In addition to the typical safety tests found in the IEC950 standard, this standard includes special sections on batteries and other safety concerns specific to UPS systems. UPS products are normally certified to this standard by VDE, TUV, SEMKO or other authorized certification body.


Enterprise Network Accounting. "Enterprise Network Accounting is software that allows end users to collect call data from routers and generate communications management reports. ENA software tracks and allocates the costs of using a corporate network or the Internet, which allows network administrators to bill users for time spent on the network. ENA software also generates traffic statistics reports that show traffic patterns, potential misuse/abuse, and network inefficiencies . As voice traffic moves to the net, communications managers need tools to track and account for network usage. ENA represents the next phase in call accounting products. "Network World" coined the term concerning an announcement by Cisco Systems regarding a partnership with Telco Research, which is developing ENA products for Cisco Systems.


To make something happen. Or, in more complex language, to set various hardware and software parameters so that the central computer will recognize those parameters and start doing what you want.


An "enabler" is a strange name for a piece of software.

Enabling Signal

A signal that permits the occurrence of an event.


See En-bloc.

Encapsulated Postscript File

EPS. A file that prints at the highest possible resolution for your printer. An EPS file may print faster than other graphical representations. Some Windows NT and non-Windows NT graphical applications can import EPS files.

Encapsulating Bridge

A LAN/WAN term. A special bridge type usually associated with backbone/subnetwork architectures. Encapsulating bridges place forwarded packets in a backbone-specific envelope ” FDDI, for example - and send them out onto the backbone LAN as broadcast packets. The receiving bridges remove the envelope, check the destination address and, if it is local, send the packet to the destination device. For a much longer explanation, see Bridge.

Encapsulating Security Payload

ESP The portion of the IPSec virtual private networking protocol which is used predominantly to provide data privacy.


  1. Encasing a splice or closure in a protective material to make it watertight.

  2. In object-oriented programming, the grouping of data and the code that manipulates it into a single entity or object. Encapsulation refers to the hiding of most of the details of the object. Both the attributes (data structure) and the methods (procedures) are hidden. Associated with the object is a set of operations that it can perform. These are not hidden. They constitute a well-defined interface ” that aspect of the object that is externally visible. The point of encapsulation is to isolate the internal workings of the object so that, if they must be modified, those changes will also be isolated and not affect any part of the program. See Object-Oriented Programming.

  3. Component lingo. Encapsulation is the isolation of a component's attributes and behaviors from surrounding structures. The technique protects components from outside interference and protects other components from relying on information that may change over time. Components are often encapsulated.

  4. An electronic messaging term. The technique used by layered protocols in which a layer adds header information to the PDU (Protocol Data Unit) form the layer above. As an example, in Internet terminology, a packet would contain a header from the physical layer, followed by a header from the network layer (IP), followed by a header from the transport layer (TCP), followed by the application protocol data.

  5. A networking term. It means carrying frames of one protocol as the data in another. Often the encapsulating protocol will be TCP/IP.

  6. See also Encapsulation Bridging.

Encapsulation Bridging

Method of bringing dissimilar networks where the entire frame from one network is simply enclosed in the header used by the link-layer protocol of the other network.


Use of a cipher process to conceal some form of communicated intelligence.


Usually refers to a "headend enclose," relay equipment enclosure hut, or a small weather proof equipment box. In short, a place to put your precious equipment and protect it from the weather and from vandals.

Enclosure Reverberation

A phenomenon of acoustics in which sound is reflected, or echoed , within an enclosure. This effect is particularly troublesome in automobile hands-free cell phone applications, as the coupling of the speakerphone, cell phone microphone, and the enclosed automobile chamber can degrade the quality of the transmitted signal.


The process of converting data into code or analog voice into a digital signal. See also PCM and ADPCM.


Encrippling is the name of a technology which Hyperlock Technologies (www.hyperlock.com) has created which allows CD owners to unlock premium content stored on music compact discs. According to Hyperlock, instead of typical encryption approaches that wrap the equivalent of a digital security envelope around a complete piece of content, Hyperlock's system removes key pieces of data from content stored on the compact disc. The content can only be played them, by retrieving the missing data from a preselected Web site, e.g. the publisher of the compact disc.


A fancy term for scrambling a message so that no one can read it except for the person for whom it's intended. In more formal terms, encryption is the transformation of data into a form unreadable by anyone without a secret decryption key. Its purpose is to ensure privacy by keeping the information hidden from anyone for whom it is not intended. In security, encryption is the ciphering of data by applying an algorithm to plain text to convert it to ciphertext . Symmetric encryption uses the same key to both encrypt and decrypt the message. Asymmetric encryption, also known as Public Key Encryption, equips each user with two keys ” a private key and a public key, both of which are provided by a trusted third party known as a Certificate Authority (CA). The public key, which is known by everyone, is used to encrypt the message. The private key, which is known only to the intended recipient, is used to decrypt the message. Each public key and private key are linked in a manner such that only the public key can be used to encrypt messages and only the private key held by each individual recipient can be used to decrypt them. See also Public Key Encryption for a longer explanation.

Here is a definition courtesy , Alcatel: Encryption is the use of an algorithm to hide the meaning of a piece of information so that it cannot be read and understood . Encryption techniques have been around since the Roman Empire in the form of simple replacement techniques. One such technique is shown in the table below where the top row represents a character from the original message and the bottom row will be the replacement for the original character.



If we wanted to disguise the word trumpet we could use our table to replace the letter t with x, r with v and so on until trumpet becomes xvyqtix. Such a simple type of encryption is great for word games , but electronic commerce and sensitive data require a much more sophisticated encryption algorithm. Current strong types of encryption are mathematical in nature and fall into three general classes: symmetric, asymmetric, and cryptographic hash algorithms.

A symmetric algorithm uses a single key to encrypt and decrypt the data. The keys in an encryption algorithm are a binary number with a specific length measured in bits. For instance a four-bit key is a binary number with values from 0000 to 1111 totaling 16 possible combinations. Different encryption algorithms use keys with different lengths. An algorithm that uses keys with 128 bits and higher is typically considered to be strong enough for electronic commerce, because a key created with 128 bits has 2128 possible combinations, which is very difficult for an attacker to crack using brute force methods. There are several types of strong encryption that use symmetric algorithms. A few of the more popular ones are: Advanced Encryption Standard (AES), the International Data Encryption Algorithm (IDEA), and finally the Digital Encryption Standard (DES).

An asymmetric algorithm, which is used in a public-key infrastructure, requires two different yet related keys to encrypt and decrypt the data. One key is a private key and the other is a public key. The private key is never given out while the public key is readily available for use. Each key can decrypt information encrypted by the other key, but cannot decrypt information encrypted by itself. Therefore, the public key is given freely but the private key is needed to decrypt anything encrypted with the public key. When two people using a public-key infrastructure exchange public keys, it is very difficult for anyone to decrypt the transmission because of the length of the keys used and the fact that the private keys are always kept secret.

Hash functions are mathematical techniques that create a binary number (called a hash value) that has a fixed-length. This number cannot be run through the algorithm in reverse to figure out the original message. The hash value is used to authenticate a message in case it is intercepted and altered in transit.

How it works is the sender will compute the hash value of the original message and then encrypt both the message and the hash value and send it to the intended receiver. Once the message is received, it is decrypted and the hash value is recomputed using the sent message. If the hash value on the receiving end is the same as the one included with the message then the message is considered to be secure. The Secure Hash Algorithm and Pretty Good Privacy (PGP) are both examples of hash functions in use today..

Encryption key

A unique, secret password, table or data block used to encrypt (i.e., encode) or decrypt (i.e., decode) data. See also Encryption and Public Key Encryption.

End Access End Office

EAEO. An end office that provides Feature Group D.

End Delimiter

ED. Sequence of bits used by IEEE 802 MAC to indicate the end of a frame. Used in token bus and ring networks, with nondata bits making ED easy to recognize.

End Distortion

In start-stop teletypewriter operations, the shifting of the end of all marking pulses except the stop pulse from their proper positions in relation to the beginning of the next pulse. Shifting of the end of the stop pulse would constitute a deviation in character time and rate rather than being an end distortion. Spacing end distortion is the termination of marking pulses before the proper time. Marking end distortion is the continuation of marking pulses past the proper time. Magnitude of the distortion is expressed in percent of a perfect unit pulse length.

End Finish

Surface condition at the optical fiber face.

End Instrument

A communication device that is connected to the terminals of a circuit.

End Node

A node such as a PC that can only send and receive information for its own use. It cannot route and forward information to another node.

End Of File

EOF. A control character or byte used in data communications that indicates the last character of the last record of a file has been read.

End Of Medium

EM. A control character used to denote the end of the used (or useful) portion of a storage medium.

End Of Message

EOM. A control character used in data communications to indicate the end of a message.

End Of Shift Routing

A call center term for a process that calls won't be left in limbo when a shift ends. See also Source/Destination Routing, Skills-Based Routing and Calendar Routing.

End Of Text Message

ETX. A control character used in data communications to indicate the end of a text message. See ETX.

End Of Transmission Block

A communications control character indicating the end of a block of Bisync data for communication purposes.

End Of Transmission Block Character

A control character used in data communications to indicate the end of a block where data are divided into blocks for transmission purposes.

End Office

A central office to which a telephone subscriber is connected. Frequently referred to as a Class 5 office. The last central office before the subscriber's phone equipment. The central office which actually delivers dial tone to the subscriber. It establishes line to line, line to trunk, and trunk to line connections. See End Office Code.

End Office Code

That part of a destination code consisting of the first three digits of a customer's seven digit directory number. It is usually expressed as an "NXX Code" where N represents digits 2 through 9 and X represents digits zero through 9.

End Office Conversion

When an end office offers "equal access." See Carrier Identification Code and 101XXXX.

End Point

A network element (component) at the end of the network. In other words, a transmitter or receiver, or an originating or terminating device.

End Span

See 802.3af.

End Station

An ATM term. These devices (e.g., hosts or PCs) enable the communication between ATM end stations and end stations on "legacy" LAN or among ATM end stations.

End System

A host computer, in the context of the Internet.

End to End Communications

Data delivered between a source and destination endpoint.

End to End Confidentiality

The provision of data confidentiality between the sender and receiver of a communication.

End to End Connection

Connections between the source system and the destination system.

End To End Loss

The loss of an installed transmission path. The loss consists of the loss of the transmission cable or fiber, splices and connectors.

End to End Service

Service that enables the end user to pass information from one point to another. The Telephone Company provides access service to the carrier and local exchange service to the end user. The carrier provides inter-exchange transmission.

End To End Signaling

A signaling system capable of generating and transmitting signals directly from the originating station to the terminating end after the connection is established, without disturbing the connection. Touchtone dialing is such a system, allowing the user to send tones to a remote computer for data or other access. See Point To Point.

End to End Testing

Refers to the testing (with assistance from the telephone company) of a Common Carrier-provided facility and access services provided by the telephone company.

End User

A highfalutin' term for a user. Any individual, association, corporation, government agency or entity other than an IXC that subscribes to interstate service provided by an Exchange Carrier and does not resell it to others. Telcordia's definition: A user who uses a loop-start, ground-start, or ISDN access signaling arrangement. In the past, "end user" meant the person placing or receiving the call. But the explosion of information technology has sparked robust disagreement over where a telecommunications transmission begins and ends.

End User Access Line

The facility between the EO (End Office) and the Network Interface (NI) at the end user's premises. The end user access line includes certain non-traffic sensitive central office equipment, the outside plant facilities, the Network Channel Terminating Equipment (NCTE), when necessary, and the NI located on the end user's premises.


See End Point.


The property of a system, subsystem, equipment, or process that enables it to continue to function within specified performance limits for an extended period of time, usually months, despite a potentially severe natural or man-made disturbance, e.g., nuclear attack, and a subsequent loss of external logistic or utility support.

Energy Communications

EC. A PBX feature which communicates with energy consuming and monitoring devices and perform functions like dimming the lights or turning down the heat in a vacant hotel room. See also Energy Control.

Energy Control

Indicates that phone system has software and hardware necessary to control and regulate the energy consuming devices in a user's facility (heating, ventilating, air conditioning, electrical machinery etc.). The system's processor transmits control signals, over existing telephone wiring where possible, to control units at each power-consuming device. This feature always includes user reconfiguration of the system's control parameters in response to operational and/or environmental changes. At one stage, AT&T and some other telephone equipment manufacturers sold energy control as a integral feature of their phone systems. The idea didn't take off for a lot of reasons.

Energy Density

A beam's energy per unit area, expressed in joules per square meter. Equivalent to the radiometric term "irradiance."

Energy Star

A U.S. Government program that mandates strict limits on power consumption on electronic equipment, like computers and monitors , to the Federal Government. Products that comply often carry the symbol of a green star.


  1. A silly way of saying Ethernet.

  2. Enhanced Network.


Exchange Network Facilities for Interstate Access. A tariff providing a series of options for connecting long distance carriers with local exchange facilities of the local telephone company.

Engineer Furnish and Install

EF&I. A way to buy a product. If you buy a PBX (or anything else) the company will ask you if you want to buy the equipment and install it yourself, or get them to engineer, furnish and install it.

Engineered Capacity

A telephone company term. The highest possible load level for a trunk group or a switching system at which service objectives are met. In general, for a switching-system, carried-load is equal to offered-load below engineered capacity, but is less than offered load above engineered capacity. Engineered capacity does not include equipment provided for maintenance or service protection.

Engineering Administration Data Acquisition System

A telephone company term. EAD. The system is composed of traffic measuring and indicating devices, data converters, data accumulators, an EADAS central control unit (CCU), and a general purpose computer. The downstream general purpose computer provides data to the data management system which in turn provides the raw data, properly formatted and for the measurement intervals requested , to other downstream programs.

Engineering Judgment

A telephone company definition. A term used by Network Engineering Managers and in various system publications to describe a behavior; expected of engineers when factual data and calculations are unavailable to justify engineering decisions.

Engineering Orderwire

EOW. A communication path for voice or data, or both, that is provided to facilitate the installation, maintenance, restoral, or deactivation of segments of a communication system by equipment operators, attendants, and controllers.

Engineering Period

A telephone company definition. Usually a one to four year period starting with the required service date of a new office or addition and concluding at the planned exhaust date of the switching equipment.

Enhanced 800 Services

A name MCI uses for a family of 800 services with additional features added to them. It includes time of day and day of week routing.

Enhanced 911

Enhanced 911 is an advanced form of 911 service. With E-911, the telephone number of the caller is transmitted to the Public Safety Answering Point (PSAP) where it is cross-referenced with an address database to determine the caller's location. That information is then displayed on a video-monitor for the emergency dispatcher to direct public safety personnel responding to the emergency. This enables police, fire departments and ambulances to find callers who cannot orally provide their precise location.

Here's an E-911 example. An emergency call is placed from a subscriber's home; the ANI (calling number) accompanies the call through the network. The dialed digits "9-1-1" identify the call as emergency, which allows the telephone network to route the call to the specialty Tandem Switch, or Selective Router, at the E-911 Central Office. Here, the Tandem uses the ANI to look up the caller's ALI (address), and uses the ALI to derive the ESN (call routing number) from the Master Address Street Guide. The ESN determines the PSAP to which the call is delivered, still carrying the ANI. If desired, the PSAP can use the ANI to again derive the ALI (address), for example, to aid in dispatching emergency personnel.

Enhanced Call Processing

An Octel term for the interactive voice response option in its voice mail system. Here's how Octel defines the term: "Companies and departments that receive a heavy volume of calls can use ECP to create menus that are presented to callers. When the system answers a call, a recorded voice instructs the caller how to use a touch-tone telephone to send call routing instructions to the system. Depending on which option is chosen , ECP's customized call routing feature allows a caller to press a single key to reach a predetermined extension, a voice messaging mailbox where he can leave a message, an Information Center Mailbox where he can listen to a series of recordings giving frequently requested information or additional levels of ECP menus. ECP menus are easily custom-built by the customer to meet its specific needs. Each menu can offer as many as ten options."

Enhanced Call Routing

An AIN (Advanced Intelligent Network) service which is an enhancement to 800 / 888 services. The calling party is voice prompted through a set of menu options which serve to define the specifics of the request and the particular needs of the caller. Based on that input, the caller is directed to the most appropriate incoming call center and agent. By way of example, language preference might be a cause for changing call routing.

Enhanced Dialing

Features allow for speed dialing, preview dialing, and manual dialing from a host or workstation application.

Enhanced DNIS

Enhanced DNIS is a combination of ANI and DNIS delivered before the first ring on a T-1 span. The number of digits delivered is configurable on a per span basis.

Enhanced IDE

An improved interface to the IDE hard disk interface. Enhanced IDE allows you to attach hard disks of larger than 528 megabytes (the largest normal IDE will handle) up to a maximum of 8.4 gigabytes. Enhanced IDE has a data transfer rate of between 11 and 13 megabytes per second, compared to the 2 to 3 megabytes per second, which normal IDE drives sport. See IDE.

Enhanced Mode

The Intel 8088 and 8086 microprocessors, used in the earliest PCs, run DOS programs using real mode. Real mode causes problems when you try to run more than one program at a time because nothing prevents a poorly designed program from invading another program's memory space, resulting in a system crash, i.e. the PC seizing up. The Intel 80386 microprocessor introduced several technical improvements. For compatibility, an 80386 can run in real mode, but also offers protected mode. In protected mode, the 80386 can address up to four gigabytes of RAM, far more than you can install in any PC. The chip (and later versions such as the 486 and the Pentium) also can simulate more than one 8086 machines, protected from one another, thus preventing memory conflicts.

Running a DOS program in the protected mode of an 80386 computer (and later versions such as the 486 and the Pentium) requires software to manage the memory. Like a traffic cop, this software ” called memory-management or the Windows operating system ” puts DOS programs into their own 640K virtual machines, where they work away without interfering with other programs. The most popular memory-management available for 80386 and 80486 is Windows. In 386 Enhanced mode, Windows takes advantage of the 80386/80486/Pentium's virtual memory capabilities. Virtual memory is a way of extending RAM. Most DOS applications swap program instructions and data back and fourth from disk rather than keep them in memory. See Expanded Memory and Extended Memory.

Enhanced Parallel Port

EPP. A new hardware and software innovation (and now a standard) which allows computers so equipped to send data out their parallel port at twice the speed of present parallel ports. There's no difference in the shape of the plug or the number of conductor. See EPP for a fuller explanation.

Enhanced Private Switched Communications Service

EPSCS (pronounced EP-SIS). A private line networking offering from AT&T which provides functions similar to CCSA. Big companies are its customers.

Enhanced Serial Interface

ESI. Now totally obsolete. It was a broader serial interface announced by Hayes Microcomputer Products, Norcross, GA, and placed in the public domain. The ESI is an extension of the familiar COM card used in personal computers. ESI includes the definition of I/O, control registers, buffer control, Direct Memory Access (DMA) to the system and interaction with attached modem devices. ESI specification is available from Hayes Customer Service at no charge. Combined with Hayes' announcement of ESI was their announcement of new Enhanced Serial Port hardware products for the IBM microchannel and IBM XT/AT or EISA bus personal computers. According to Hayes, the ESI spec and the supporting ESP hardware provide a " cost-effective " communication coprocessor to manager the flow of data between an external high speed modem and PC. This technology prevents loss of data resulting from buffer overflow errors and provides maximum data throughput for high speed modems. Hayes said that the combination of ESP and ESI would allow through-the-phone modem speeds of up to 38.4 Kbps.

Enhanced Serial Port

See Enhanced Serial Interface.

Enhanced Service Provider

ESP. An ESP is a company that provides enhanced or value-added services to end users. An ESP typically adds value to telephone lines using his own software and hardware. Also called an IP, or Information Provider. An example of an ESP is a public voice mail box provider or a database provider, for example, one giving the latest airline fares. An ESP is an American term, unknown in Europe, where they're most called VANs, or Value Added Networks. See also Open Network Architecture and Information Provider.

Enhanced Services

Services offered over transmission facilities which may be provided without filing a tariff. These services usually involve some computer related feature such as formatting data or restructuring the information. Most Bell operating companies (BOCs) are prohibited from offering enhanced services at present. But the restrictions are disappearing .

The FCC defines enhanced services as "services offered over common carrier transmission facilities used in interstate communications, which employ computer processing applications that act on the format, content, code, protocol or similar aspects of the subscriber's transmitted information; provide the subscriber additional, different or restructured information; or involve subscriber interaction with stored information." In other words, an enhanced service is a computer processing application that messes in some way with the information transmitted over the phone lines. Value-Added Networks, Transaction Services, Videotex, Alarm Monitoring and Telemetry, Voice Mail Services and E-Mail are all examples of enhanced services.

Enhanced Small Device Interface

An interface which improves the rate of data transfer for hard disk drives and increases the drive's storage capacity.

Enhanced Unshielded Twisted Pair

EUTP. UTP (Unshielded Twisted Pair) cables that have enhanced transmission characteristics. Cables that fall under this classification include Category 4 and above.

Enhanced Variable Rate Vocoder



Embedded Network Interface. An ENI might be in the form of an applications program that includes network controller logic for a wide range of printers, for example. Or it might be in the form of network interface logic such as PPP and TCP/IP embedded in a chip that is part of a modem card that fits inside a laptop.


Electronic Numerical Integrator and Computor (spelled with an O). Early computer, built in 1944.


Enterprise Network Operating Systems. A Sun Microsystems term. Part of Sun's Networking Solutions, ENOS provides the foundation for Sun's networking environment. ENOS combines NFS (Network File System) and the TCP/IP protocol suite into its WebNFS. NFS is a Sun system that has become the de facto standard for global file sharing.


ENQuiry character. A control character (Control E in ASCII) used as a request to obtain identification or status. Abbreviation for enquiry. The binary code is 0101000 and the hex is 50.

ENQ/ACK Protocol

Hewlett-Packard communications protocol in which the HP3000 computer follows each transmission block with ENQ to determine if the destination terminal is ready to receive more data. The terminal indicates its readiness by responding with ACK.


See Berners-Lee.

Enriched Services Providers

Those third-party service providers (other than Network Providers) who provide value-added services that are accessed through telecommunications networks.


Emergency Number Services.


ETSI National Standardization Organizations (ETSI).


ENergy TELECommunications and electrical association, the oldest nationwide user group in telecommunications. It is an association of communications managers and engineers in the oil, gas, pipeline and utility industries. ENTELEC played an important role in the early opening of competition in the telecommunications industry, including the famous "Above 890" decision, which allowed private companies to build their own long distance microwave system. The decision was called "Above 890" because electromagnetic waves in the radio frequency spectrum above 890 Megahertz (million cycles per second) and below 20 Gigahertz (billion cycles per second) are typically called microwave. Microwave used to be a common method of transmitting telephone conversations and was used by common carriers as well as by private networks. Now fiber is far more common. Microwave signals only travel in straight lines. In terrestrial microwave systems, a single transmission is typically good for 30 miles, at which point you need another repeater tower. Microwave is the frequency for communicating to and from satellites . ENTELEC was formerly known as the Petroleum Industry Electrical Association.

Entering Distribution

A call center term. In this mode of the alerting state, a call is being presented to an ACD group or hunt group in preparation for distribution to a device associated with that group. This mode is indicated by a Delivered event with a cause code of Entering Distribution.


Enterprise means the whole corporation. It tends to refer to corporations with more than one location. See Enterprise Computing.

Enterprise Calendaring

See iCalendar.

Enterprise Computing

Enterprise means the whole corporation. Enterprise computing refers to the computing applications on which a company's life depends: order entry, accounts receivable, payroll, inventory, etc. It is also known by the phrase "mission critical." See also Enterprise Network.

Enterprise Network

The word Enterprise was invented by IBM. It means the whole corporation. An enterprise-wide network is one covering the whole corporation. Local PBXs. Local area networks. Internetworking bridges. Wide area networks, etc, etc. See also Corporate Network and Enterprise Computing.

Enterprise Number

A service provided by AT&T and the Bell operating companies (a.k.a. the Bell System) years ago which allowed people to make collect calls and have their calls automatically accepted by the company at the other end. It was very expensive. It has largely been replaced with 800 IN-WATS service, which is much more successful.

Enterprise Resource Management

ERM. Also known as Enterprise Resource Planning (ERP). See ERP for a full definition.

Enterprise Resource Planning

ERP. A concept developed by The Gartner Group to describe the next generation of manufacturing business systems and MRP (Materials Resource Planning) software. See ERP for a full definition.

Enterprise RMON

A proprietary extension of RMON and RMON-2, Enterprise RMON was developed by NetScout Systems (formerly Frontier Software Development) and is supported by several other vendors , including Cisco Systems. Enterprise RMON's extensions monitor FDDI and switched LANS. See RMON, RMON-2.

Enterprise Server

A Sun Microsystems term, Part of Solaris' Server Suite. Used to develop and deploy mission critical applications on large server systems. Provides distributed computing. Comes with Solstice DiskSuite and Networker products for on-line backup and recovery.

Enterprise Solution

Software that enables individuals and groups (either within an organization or part of a virtual organization beyond one company) to use computers in a networked environment to access information from a wide range of sources, collaborate on projects, and communicate easily with text, graphics, video, or sound.


  1. An active element within an OSI layer or sublayer.

  2. A telephone company definition. A group of lines served by common originating equipment.

Entity Coordination Management

The portion of connection management which controls bypass relays and signals connection management that the medium is available.

Entity Nongrowth

A telephone company term. Also referred to in some areas as 'capped' or 'floating.' The term non-growth entity will be used to identify those entities where we do not intend to add capacity. However, we must always insure that these entities continue to provide objective levels of service.

Entrance And Exit Ramps

The companies who control access to the internet and other networks of the information superhighway, whatever that is.

Entrance Bridge

A terminal strip that is an optional component in a network interface device and is provided for the connection of ADO cable.

Entrance Facility

EF. An entrance to a building for both public and private network service cables (including antennas) including the entrance point at the building wall and continuing to the entrance room or space. Entrance facilities are often used to house electrical protection equipment and connecting hardware for the transition between outdoor and indoor cable. The Entrance Facility includes overvoltage protection and connecting hardware for the transition between outdoor and indoor cable.

Entrance Point/Telecommunications

The point of emergence of telecommunications conductors through an exterior wall, a concrete floor slab, or from a rigid metal conduit or intermediate metal conduit.

Entrance Room/Telecommunications

A space in which the joining of inter or intra building telecommunications backbone facilities takes place.


The deliberate planting of apparent flaws in a system for the purpose of detecting attempted penetrations.

Entrenched Transactors

Banking industry jargon for people who refuse to use cost-saving ATMs, preferring to deal only with more expensive human bank tellers.

Entropic coding

Entropic coding is lossless compression. It exploits information- theoretic redundancy in the signal. This redundancy originates in the fact that not all sequences of bits are equally likely in the PCM data; some sequences occur more often than others. Entropic coding uses a lossless compression scheme, such as Lempel-Ziv or Huffman coding, to use fewer bits to represent the sequences that occur most often, and more bits to represent the sequences that occur less often. In this way, the average sequence length may be compressed by a factor which depends on the classical information content of the bitstring. Entropic coding is used in MP4 audio.

Entropy Coding

A category of compression and coding algorithms that preserves all source information (i.e. it's lossless) so that it can be reconstructed with no loss of information. Compression is achieved by a more efficient coding which reduces the entropy (or " disorder ", roughly ). Entropy encoding is most successful in images where there is a great deal of redundancy (e.g. solid background, text foreground). See Entropic Coding, which is the preferred way of spelling.

Entry Border Node

An ATM term. The node which receives a call over an outside link. This is the first node within a peer group to see this call.


ENUM, in short, is a proposal to map all phone numbers to IP addresses. ENUM isn't an acronym, but it could have been short for Electronic NUMber, or something of the sort . ENUM is a proposed standard (RFC 2916) from the IETF (Internet Engineering Task Force) for a DNS-based (Domain Name Server) method for mapping telephone numbers to URLs (Uniform Resource Locators, i.e., Web addresses) and, ultimately, to IP addresses. The format for telephone numbers is specified in the ITU-T E.164 standard, and the formats for URLs, IPv4 and IPv6 are standardized by the IETF. So, the translation between the two is relatively straightforward. Missing is a standardized method, set of protocols, database responsibility, and various other specifics for doing so. ENUM addresses those issues through the DNS-based approach for number registration, directory mapping, translation processes, and various other specifics that must be resolved for the concept to work on a global and seamless basis. A global domain, e164.arpa, has been set aside by the IAB (Internet Architecture Board) for the system. Here's how ENUM is proposed to work:

You dial a telephone number for a company connected to the Internet. The telephone number is reversed, with the last digit becoming the first, and the first digit becoming the last. This reversal is necessary for the telephone number order to match the logic used in URLs, where the TLD (Top Level Domain) ” ".com" or ".us," for example ” must be considered first in order to drive the remainder of the address search to the proper DNS administered under the proper registration authority. Traditional telephone numbers, of course, take the reverse approach, with the access code (e.g., 011 for international long distance, or 1 for domestic long distance) coming first, followed by the country code, the area code, the CO prefix, and the line number. This numbering scheme must be reversed in order for the E.164 number to be resolved by the DNS and translated into a URL, which then is translated into an IP address. Now, if the number dialed is not in the ENUM DNS database, the call is connected over the PSTN. If, however, it is in the database, the available services are identified, and the call is completed over the Internet or other IP-based network. As a result, ENUM has the potential to become one of the basic underpinnings of a convergence between the PSTN and the Internet.

ENUM proposes to employ the E.164 telephone number as a global identifier that can be used to direct a message to any device or application connected to the Internet, assuming that the device or application has registered the availability of that particular service. Any necessary conversions in protocols would have to be made, of course, either by the devices or through gateways. For example, a fax machine could send a message directly to an e-mail address, and an e-mail could be sent directly to an IP-enabled fax machine. Similarly, instant messaging and unified messaging could be supported across device types and networks. Voice over IP (VoIP) could be supported more easily. Voice mail over the Internet would be enabled through the use of the existing VPIM (Voice Profile for Internet Mail) standard.


A Windows term. A Plug and Play device driver that detects devices below its own device node, creates unique device IDs, and reports to Configuration Manager during startup. For example, a SCSI adapter provides a SCSI enumerator that detects devices on the SCSI bus.


  1. In mathematics, the outer boundary of a family of curves obtained by varying a parameter of a wave has been known since mid-19th century as the envelope. This is the strict mathematical definition. From this we have the expression "pushing the envelope," which today means pushing something's performance past what it was designed for. Actually this expression should really be "pushing the outside of the envelope." Aeronautical engineers have since applied this word to the limits of aircraft operation. When a test pilot presses against those outer limits (of speed, gust, maneuver and flight) he pushes the outside of the envelope. Tom Wolfe popularized the phrase in his 1979 book "The Right Stuff" about astronauts.

  2. The part of messaging that varies in composition from one transmittal step to another. It identifies the message originator and potential recipients, documents its past, directs its subsequent movement by the MTS (Message Transfer System) and characterizes its content.

  3. The first envelopes with gummed flaps were produced in 1844 in Britain. They were not immediately popular because it was thought to be a serious insult to send a person's saliva to someone else. A duel was fought because the person receiving the letter suspected that the sender had sealed the envelope with his tongue.

Envelope Capacity

There are two common usages of this term:

  1. The number of bytes the payload envelope of a single frame can carry. The SONET STS payload envelope is the 783 bytes of the STS-1 frame available to carry a signal. Each virtual tributary(VT) has an envelope capacity defined as the number of bytes in the VT less the bytes used by VT overhead.

  2. The bandwidth allocated within each SONET STS-1 channel to carry information endto-end. Also known as information payload. 50.112 Mb/s.

Envelope Delay

The difference, expressed in time, for signals of different frequencies to pass through a phone line. Some frequencies travel slower than others in a given transmission medium and therefore arrive at the destination at different times. Delay distortion is measured in microseconds of delay relative to the delay at 1700 Hz. Also called Delay Distortion.

Envelope Delay Distortion

The distortion that results when the rate of change of phase shift with frequency over the bandwidth of interest is not constant. It is usually stated as one-half the difference between the delays of the two frequency extremes of the band of interest. See Envelope Delay.

Envelope Distortion

Distortion of the transmitted signal which results from the different transmission speed characteristics of different frequency components to the signal. Mathematically it is the derivative of the phase shift with respect to frequency.


The place your telephone system's main cabinet and main electronics live. While most PBX vendors will specify the room's characteristics, the ultimate responsibility for the room is yours, the user. Not designing your telephone system's environment correctly is tantamount to jinxing your telephone system from the start.

Here are some things to watch out for (your vendor has a more comprehensive list):

  1. Sufficient air conditioning? Telephone systems give off heat. You need some way of getting rid of the heat. If you don't, you will blow some of your phone system's delicate electronic circuitry.

  2. Sufficient space? Is there room for technicians to get in and around your telephone system so they can repair it? Will you have room for additional cabinets when you need to grow your phone system?

  3. Sufficient and correct power? Will you have sufficient clean commercial AC power? Will you require isolation regulators? Or you will require extensive wet cell batteries? Will you have space?

  4. Will you have a solid electrical ground? Can you find somewhere solid to ground your telephone system to ” other than the third wire on the AC power, which is not suitable for most telephone systems? Beware of cold water pipes which end in PVC plastic pipes.

Environment Variable

Orignally a UNIX term, now also used in Windows. It means a variable that is set in the shell in such a way that it is available to all child processes (programs, other shells , etc.) of the shell. (It's what you get when you "export" a variable.) Windows defines it as a string consisting of environment information, such as a drive, path, or filename, associated with a symbolic name that can be used by Windows. You use the System option in Control Panel or the set command from the Windows NT command prompt to define environment variables .


  1. A palmtop communicator introduced by Motorola in March of 1994. The device lets its users receive and transmit messages via Ardis, a network owned by Motorola and IBM. Envoy contains software from General Magic.

  2. Spectrum Envoy is a DSP-based PC-board used for "telephone management" from a company called Spectrum Signal Processing, Burnaby, BC. Telephone management includes voice mail, contact manager, upgradable fax/modem, business audio, etc.


  1. End Office. Typically your own telephone company central office ” the one that gives you dial tone and through which you make your local and long distance phone calls.

  2. Erasable Optical drive. EO drives act like hard drives yet offer virtually unlimited storage because their cartridges are removable. Each cartridge sports at least 650 MB. Some sport 1 gigabyte.

  3. EO was a startup in Mountain View, CA which did wireless data. It made a device called EO Personal Communicator 440 and 880. It uses GO's PenPoint operating system and the Hobbit microprocessor made by AT&T, which is "optimized" for telecommunications. In fall of 1994, AT&T closed EO down and stopped the sale of EO devices. It was too expensive and wasn't selling. An excellent book was written about EO. It is called "Startup; A Silicon Valley Adventure Story." It was written by Jerry Kaplan, one of EO's founders. The book is published by Houghton Mifflin.


End Of Address. A header code.


End Of Block. A control character or code that marks the end of a block of data.


Embedded Operations Channel. An operations channel for purposes of network management purposes (e.g., circuit monitoring and testing) which is embedded in a communications protocol. An EOC is a dedicated channel for such purposes, ensuring that network management functions can always be accomplished on a non- intrusive basis. In other words, the management of the performance characteristics of the circuit will not intrude on the ability of that circuit to support the transmission of the data that supports the end user's applications. For example, ISDN BRI (Basic Rate Interface) provides for two B (Bearer) channels of 64 Kbps each, and a D (Delta, or Data) channel of 16 Kbps, for a total of 144 Kbps. The 16-Kbps D channel always is available, on a priority basis, for network management (i.e., signaling and control) purposes, and without affecting the circuit's ability to support the end user's applications running over the two B channels. See also BRI.


End Of Day, a favorite Microsoft expression.


See Electronic Order Exchange.


The abbreviation for End Of File. MS-DOS files and some programs often mark the end of their files with a Ctrl Z ” or ASCII 26.


End of Message (indicator). In ATM network, EOM is an indicator used in the AAL that identifies the last ATM cell containing information from a data packet that has been segmented.


End of Procedure frame. A frame indicating that the sender wants to end the call.


End of Transmission, End of Tape.


European Organization for Testing and Certification.


Engineered OrderWire.

EPA Energy Star

Monitors that comply with this standard consume less electricity by powering down when not in use.


Electronic Private Automatic Branch eXchange. A fancy name for a modern PBX. Other fancy names include CBX, Computerized Branch Exchange.


Electronic Product Code. See also RFID.


Early Packet Discard. A technique used in ATM networks for congestion control in support of both Classical IP over ATM and Local Area Network Emulation (LANE). Such data is transmitted in the form of packets and frames, respectively, each of which typically is a subset of a much larger set of data such as a file. In the case of Classical IP over ATM, each data packet can be variable in size , up to a maximum of 65,536 octets (e.g., bytes). As the IP data packet enters the ATM switch on the ingress side of the ATM network, it is stored in a buffer until such time as the ATM switch can segment it into cells, each with a payload of 48 octets ” there can be a great many such cells for each packet ” and act to set up a path and circuit to forward the stream of cells which comprise the original packet. If a given cell is dropped for some reason (e.g., there is not enough buffer space at either the incoming or the outgoing buffer within the switch, the integrity of the original packet is lost through this phenomenon known as "packet shredding ." Early implementations of Classical IP over ATM simply forwarded the remainder of the cells associated with that packet. So, some cells made it to the ATM switch at the egress edge of the network, and some cells didn't. When the cells were reassembled into the packet as they exited the ATM network, the result was an incomplete packet. The higher layer protocols then requested a retransmission of the entire packet. If the ATM network was highly congested , this occurrence was repeated many times, thereby contributing to further congestion. Partial Packet Discard (PPD) involves numbering each cell associated with a segmented packet as it enters the ATM domain through the inbound buffer of the ingress switch. If any cell is dropped, the entire stream of cells associated with the packet is dropped. PPP enhances the performance of the ATM network by dropping those cells, which serve no purpose as the entire packet will be transmitted in either case. PPP is an earlier, and less sophisticated, technique that largely has been replaced by Early Packet Discard (EPD), which acts to discard the entire cell stream associated with that packet if there is not enough buffer space at either the incoming or the outgoing buffer within the switch, with that determination being a function of a programmable threshold. Discarded packets are detected as missing by the higher layer protocols, and retransmissions are requested. See also ATM, Classical IP over ATM, LANE, and PPD.

Ephemeral Key

A public key or a private key that is relatively short-lived.


The predictions of current satellite position that are transmitted to the user in the data message of a GPS (Global Positioning System) satellite message.

Newton[ap]s Telecom Dictionary
Newton[ap]s Telecom Dictionary
ISBN: 979387345
Year: 2004
Pages: 133

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