E

E1

European version of North American T1, at 2.048 Mb/s.

EAN

See European Article Numbering system.

EARN

See European Academic Research Network.

EBCDIC

See Extended Binary Coded Decimal Interchange Code.

ECC

Enter Cable Change

ECHO

A portion of the transmitted signal returned to the source with sufficient magnitude and delay to cause interference. OR Echo Protocol.

ECHOPLEX

Checking data integrity by returning characters to the sending station for checking.

ECL

End Communication Layer

ECMA-179

STANDARD ECMA-179, Services For Computer Supported Telecommunications Applications (CSTA), European Computer Manufacturers Association.

ECMA-180

STANDARD ECMA-180, Protocol For Computer Supported Telecommunications Applications (CSTA), European Computer Manufacturers Association.

ECMA/52

Technical Report ECMA/52, Computer Supported Telecommunications Applications (CSTA), European Computer Manufacturers Association.

ECN

See Explicit Congestion Notification.

ECONFIG

Ethernet Configuration

ECSA

Exchange Carriers Standards Association

ECU

Engine Control Unit

ED

Text line editor

EDI

Electronic Data Interchange

EDV VIRUS

After infecting six other disks while it is active in memory, disables the keyboard and overwrites the first three tracks of every disk on the system, then displays the message "That rings a bell, no? From Cursy."

EFI

Electronic Fuel Injection

EGA

See Enhanced Graphics Array.

EGP

See Exterior Gateway Protocol.

EIA

See Electronics Industry Association.

EIA RS-232

See CCITT V.24.

EIS

See Enterprise Information System

EISA

See Extended Industry Standard Architecture.

EKTS

See Electronic Key Telephone Service.

ELAP

EtherTalk Link Access Protocol

ELECTRONIC KEY TELEPHONE SERVICE

This is a service that provides PBX-like capabilities using ISDN add-on features. It ties these add-on features to keys on your ISDN telephone, allowing you to have a hold button or a forward button, for example.

ELECTRONIC MAIL MESSAGE

A message sent privately to one or more explicitly-named individuals.

ELECTRONICS INDUSTRY ASSOCIATION

An organization of electronics manufacturers that establishes electronic interface standards.

ELM

Initials of the person who compiled this list.

EMACS

(Emacs Makes A Computer Slower) "GNUware" Well known editor from the Free Software Foundation. Available for many computer systems. FTP from ftp.std.com

EMAIL ADDRESS

Internet Email addresses are based on UNIX Email addresses. These have the form "person@machine.enterprise". The "person" field is the user id of the person on the mail host machine. The "machine" field conveys the network name of the mail host. The "enterprise" field is used to place types of computer hosts in a hierarchy. .com = commercial, .edu = collegesand universities, .gov = government agencies, <country> for any type of enterprise in another country, ex: .uk for United Kingdom.

EMBED

Places an object's native and presentation data within an object. All information necessary to edit the object is contained in the document. Requires more overhead, but the object can be transferred along with the document to another computer.

EMCON

Emission Control Protocol

EMFIS-CNTL

EMFIS Control Service

EMFIS-DATA

EMFIS Data Service

EMM

See Expanded Memory Manager.

EMM386.EXE

The Microsoft 386 expanded memory manager.

EMP

Electro-Magnetic Pulse

EMS

See Expanded Memory Specification.

ENCAPSULATE

To enclose one complete entity (for example, a UDP datagram or a TCP segment) in the data area of a lower-layer entity such as an IP packet.

ENCAPSULATION

In object-oriented programming, the grouping of data and the code that manipulates it into a single object. If a change is made to an object class, all instances of that class (that is, all objects) are changed. Encapsulation is one of the benefits of object-oriented programming. The technique used by layered protocols in which a layer adds header information to the protocol data unit (PDU) from 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.

ENCODING

The process of creating a compressed file.

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 SYSTEM

A host system, in the OSI protocol, that performs the functions of all of the layers of the OSI reference model.

END SYSTEM HELLO

An ES originated packet that passes information to an IS.

END SYSTEM TO INTERMEDIATE SYSTEM PROTOCOL

The protocol that the ESs and ISs use to recognize and communicate with each other.

END USER LAYER

The seventh layer of the SNA model. The end user layer is the interface between the SNA network and user applications.

END-TO-END

Services referred to by the lower four layers of the OSI reference model. A packet forwarded from one host to another host over the network uses end-to-end services.

END-TO-END SIGNALING

The use of DTMF signals to perform access and control operations from a remote location.

ENHANCED GRAPHICS ARRAY

(EGA) A display technology for the IBM PC. It has been replaced by VGA. EGA pixel resolution is 640x350. Also called Enhanced Graphics Adapter.

ENHANCED PARALLEL PORT

(EPP) Existed prior to IEEE 1284. No software is required for data maintenance. It uses hardware shortcuts to reduce the large number of software commands previously required to transmit bytes and monitor transmissions. As a result, overall parallel port data transfer speeds have soared by as much as 15:1 - to rates as high as 2Megabytes per second, which is fast enough to drive multimedia CD-ROMs and other speed hungry devices. When an I/O instruction is executed, EPP hardware synchronizez with an extenal peripheral. And since software isn't needed, transmissions take place in one I/O cycle: all handshaking is automatic. Many Pcs made after mid-1993 are equipped with EPP technology; EPP ports are most often found on laptops using the Intel 386SL chipset with the 360SL IO support chip.

ENHANCED SMALL DEVICE INTERFACE

(ESDI) A drive controller type that utilizes a hard drive as a slave unit. ESDI controllers generally drive only two disk drives and have an on-board processor to translate drive geometry, manage I/O requests, and provide caching.

ENTERPRISE INFORMATION SYSTEM

A software system that brings strategic corporate information to company employees in a way that improves their ability to make important business decisions.

ENTITY

OSI terminology for a layer protocol machine. An entity within a layer performs the functions of the layer within a single computer system, accessing the layer entity below and providing services to the layer entity above at local service access points.

EOC

Emergency Operations Center

EOT

End of Transmission

EPP

See Enhanced Parallel Port

EPS

Electronic Power Steering

EPS

Encapsulated PostScript.

ERROR CONTROL

The encoding of text or data so that a receiving modem can detect and sometimes correct errors in data transmissions. LAPM and MNP classes 1 through 4 are two different error control protocols.

ERROR LOG

A workstation log of error information, for use in problem determination by your designated support organization. The LAN Distance product uses FFST/2 to record error log information.

ERROR MESSAGE LOG

A workstation file containing a copy of all error and warning messages generated at that workstation. It might also contain Error Reports. (See also Error Report).

ERROR REPORT

An error message generated by a remote LAN Distance Connection Server workstation, sent to a LAN Distance administrator as a pop-up, and written to the LAN Distance administrator's Error Message Log.

ES

See End System.

ES-IS

See End System to Intermediate System Protocol

ESCAPE SEQUENCE

A sequence of three characters (normally +++) that switches the modem from the on-line mode to the command mode without breaking the telephone connection.

ESF

Extended Superframe Format

ESH

See End System Hello.

ESSI

A part programming format originally developed by the Central Institute for Industrial Research in Norway. A commonly used format in Europe and with ship-building industry world wide.

ETHERNET

Ethernet was created in 1973 at Xerox PARC during the development of a personal computer called the Alto. Ethernet was derived from the University of Hawaii's ALOHA Packet Radio Network and was originally called Alto ALOHA Network. ALOHA broadcast packets with randomized retransmissions. Ethernet was publicly introduced in 1976 with the publication of the paper "Ethernet: Distributed Packet Switching for Local Computer Networks" by Robert Metcalfe and David Boggs. In 1980, Digital Equipment, Intel, and Xerox Corporations jointly developed a standard Ethernet. The result was a 10Mb/s Ethernet called DIX (DEC, Intel, and Xerox) Ethernet. This standard indicates only how the communications take place, not the media used. The current Ethernet specification is Version 2.0, which was published in November of 1982. Though the term 'Ethernet' is commonly used to refer to both Digital-Intel-Xerox Ethernet II and IEEE 10BASE-5 standards, technical differences exist in terminology and frame formatting. The differences in frame formatting make Ethernet II and 802.3 LANs incompatible, though they use the same cabling and physical specification. IEEE does not use the term 'Ethernet' anywhere in their specifications. With Ethernet, each station has a controller and a transceiver that attaches it to the network. The controller is used to build and disseminate packets. The transceiver, which may or may not be a part of the controller, taps into the network to send and receive packets for the controller. Ethernet NICs using CSMA/CD running at 10Mb/s are bountiful, as they are produced by many manufacturers. Although the IEEE standard defines a maximum trunk length of 600 feet for Thin Ethernet, 3Com's line of NICs, for instance, is capable of supporting maximum trunk lengths up to 1000 feet in length. Patch cables used on Ethernet introduce reflections onto the network cable and are therefore not supported. However, for relatively small networks, the detrimental effects of using patch cables may not be noticeable. The term generally used to refer to CSMA/CD LANs, based on 802.3 or Ethernet II standards. See CSMA/CD

ETHERNET II

The original Ethernet design developed by Digital, Intel, and Xerox in the late O70s. Ethernet II design only includes thick Ethernet cabling with external transceivers, but today is compatible with all IEEE 802.3 physical specifications and devices. Ethernet II frame formatting differs from and is not compatible with 802.3 frame formatting. Ethernet II frame formatting is commonly used in TCP/IP networks and can be used with NetWare ODI drivers and some (but not all) traditional IPX drivers. Care must be taken with NetWare to observe and correct frame incompatibilities between Ethernet II and 802.3 frames on a single LAN. Also see CSMA/CD and Ethernet.

ETHERNET SNIFFING

Listening (with software) to the raw ethernet device for packets that interest you. When your software sees a packet that fits certain criteria, it logs it to a file. The most common criteria for an interesting packet is one that contains words like "login" or "password."

ETHERTALK

Apple Computer's protocol for Ethernet transmissions.

EUNET

European UNIX Network.

EUROPEAN ACADEMIC RESEARCH NETWORK

(EARN) A network using BITNET technology connecting universities and research labs in Europe.

EUROPEAN ARTICLE NUMBERING SYSTEM

The international standard bar code for retail food

EUROPEAN WORKSHOP FOR OPEN SYSTEMS

(EWOS) The OSI Implementors Workshop for Europe. See OIW.

EUUG

European UNIX Users Group.

EVEN PARITY

A "dumb" terminal data-verification method in which each character must have an even number of "1" bits.

EVIL EMPIRE VIRUS

Overwrites root directory entries in sector 10 of floppy disks (if any).

EWOS

See European Workshop for Open Systems.

EX

Text line editor

EXCA

See Exchangeable Card Architecture

EXCHANGEABLE CARD ARCHITECTURE

(ExCA) An extension to the PCMCIA specification, added by Intel, to ensure PCMCIA cards' interoperability on host systems using Intel CPUs.

EXECUTABLE (FILE)

A file containing coded instructions to be executed by the computer. Executable files include programs and overlays.

EXECUTABLE FILE VIRUS

Viruses infect executable files by copying the virus code to the program file, either by overwriting part of the existing program code (an overwriting virus), or by appending the virus code to the end of the program file (a parasitic virus). Parasitic program-infecting viruses must modify the program file to assure that the virus code executes first. Because overwriting viruses destroy the executable code in infected programs, they are easy to detect and eliminate (by deleting and reinstalling the infected programs). For this reason, only one overwriting virus is commonly seen. The Lehigh virus only infects COMMAND.COM. Since it overwrites COMMAND's stack, copies of COMMAND.COM infected with Lehigh can still execute. Some program-infecting viruses infect only .COM files, while others infect only .EXE files. Some (like Lehigh) infect only COMMAND.COM. Others infect any .COM file except COMMAND.COM. Some viruses also infect overlay files (.OVL) or the hidden DOS system files (IBMBIO.SYS and IBMDOS.SYS or IO.SYS and MSDOS.SYS).

EXECUTE IN PLACE

(XIP) A technique by which software placed on a PCMCIA-compatible ROM card can be executed directly from the card itself instead of being loaded into RAM first.

EXPANDED MEMORY

Memory provided by a physical add-in memory card or through a 386 expanded memory manager. Memory above the DOS 640Kb limit of conventional memory that is accessed by memory paging. You need special software, conforming to an expanded memory specification, to take advantage of expanded memory. Expanded memory is made available to application software as 16K pages, mapped into a 64K page frame. Having expanded memory requires that you have an Expanded Memory Manager (EMM.SYS for example), to "manage" the expanded memory. The driver associates the pages of physical memory to the pages in the reserved DOS area. Only programs written to use expanded memory can utilize this process.

EXPANDED MEMORY MANAGER

(EMM) A driver that provides a software interface to expanded memory. An expanded memory manager is specific to a particular physical expanded memory board or uses the 80386 processor to emulate expanded memory in extended memory.

EXPANDED MEMORY PAGE FRAME

The 64Kb area used as a mappable space. A minimum of four contiguous 16Kb pages are taken from the reserved DOS memory between 640K and 1 Mb. Typically, the address space used is between 768K and 896K. The area of reserved for expanded memory address space used to access expanded memory is made up of 16Kb sections called pages.

EXPANDED MEMORY SPECIFICATION

A description of a technique for adding memory to PCs to bypass the 640K limit on addressable memory. The EMS supports additional memory through a hardware expansion board and an expanded memory manager. To use expanded memory, an application must be specifically designed to interact with an expanded memory manager. There are two expanded memory specifi cations: LIM 3.2 provides for a maximum of four contiguous 16K bankable pages; LIM 4.0 provides for a maximum of sixty-four 16K bankable pages, which do not have to be contiguous.

EXPLICIT CONGESTION NOTIFICATION

A frame relay protocol mechanism that signals source and destination user devices that network congestion is occurring.

EXTENDED BINARY-CODED DECIMAL INTERCHANGE CODE

(EBCDIC) An 8-bit data transmission code developed by IBM and used primarily for synchronous communication functions off the mainframe such as message handling, code conversion, and error control. EBCDIC is for mainframes what ASCII is for microcomputers to represent different characters.

EXTENDED INDUSTRY STANDARD ARCHITECTURE

(EISA) A computer bus and interface card design based on 32-bit bus mastering. EISA is an extension to ISA bus design and enables EISA and ISA interface cards to be used in a single type of bus interface slot. EISA requires a special card for 32-bit operations but maintains compatibility with the older ISA. Introduced in 1988 by a consortium made up of AST Research, Compaq, Epson, Hewlett-Packard, NEC, Olivetti, Tandy, Wyse, and Zenith. Also see ISA and MCA.

EXTENDED LAN

A network consisting of LANs connected by bridges (up to 7 bridges).

EXTENDED MEMORY

The memory at physical addresses from 1024K that can be accessed by a 80x86 CPU running in protected mode. The 8088 and 8086 microprocessors can only access 1Mb of address space, (640Kb conventional and 384Kb reserved memory). Only 80286 (or greater) CPU's have the ability to address memory above the 1Mb boundary. The 80286 chip can access 16Mb of total address space, and the i386 chip can access 4 gigabytes of total address space. The DOS operating system was not designed to access memory above the 1Mb address boundary, which means that DOS programs do not automatically have access to extended memory. However, many DOS based computers do have more than 1Mb of memory on the motherboard Certain DOS applications, (such as Windows 3.x), and the OS/2 operating system do use extended memory because they were specifically written to use extended memory.. Windows version 3.0 and later take full advantage of ex tended memory, including all memory above 640K, when running in standard mode or 386 enhanced mode. No special drivers are needed to access extended memory. Only programs that are written to use extended memory can utilize extended memory. Linear memory above the DOS 640Kb limit of conventional memory. Often used for RAM disks and print spoolers.

EXTENDED MEMORY MANAGER

(XMM) A driver such as HIMEM.SYS that is necessary to access extended memory. Applications do not have to be customized to interact with an extended memory manager to use extended memory under Windows 3.x. In some applications, the extended memory manager is referred to as an MS-DOS Extender.

EXTENDED MEMORY SPECIFICATION

(XMS) A Microsoft standard that provides a way for real mode applications to access extended memory. non-Windows applications running under Windows 3.x can use the XMS to access extended memory. The XMS document and sample source code is available from the Microsoft Information Center.

EXTENDED SERVICES

A set of functions that give you the ability to define and manage the resources of multiple servers as a single set of resources, controlled from a single machine.

EXTERIOR GATEWAY PROTOCOL

A protocol between ASs that advertises the IP addresses of the networks.

EXTERNAL DATA REPRESENTATION

(XDR) A standard for machine- independent data structures developed by Sun Microsystems. Similar to ASN.1.

EYACC

Modified YACC allowing much improved eror recovery