- E1 The European standard for high-speed data transmission at 2.048Mbit/s - 32 64Kbit/s channels are provided.
- Earth station Transmitting or receiving point for satellite transmission.
- EBCDIC (Extended Binary Coded Decimal Interchange Code) An IBM-developed eight-bit binary code that can represent 256 characters. It allows the representation of control codes and graphics in a logical format. It was created to represent data in particular types of data processing and communications terminal devices.
- Echo cancellation A technique used in high-speed modems to isolate and remove unwanted signal energy created by echoes of the transmitted signal. (An echo is the return of a transmitted signal). It would be noticeable by its absence on transatlantic or other time-differentiated phone conversations.
- ECMA (European Computer Manufacturers Association) An organization dedicated to the co-operative development of standards applicable to computer technology. It works closely with certain ITU-TS Study Groups and ISO Sub-committees.
- EDI (Electronic Data Interchange) The interchange of trading information through the use of an electronic messaging system. A form of paperless trading that is rapidly expanding through organizations such as Geis.
- EGP (Exterior Gateway Protocol) The protocol used by a gateway in one autonomous system to advertise the IP addresses of networks in that system to a gateway in another autonomous system.
- EIA/TIA The US Electronics Industries Association and Telecommunications Industries Association which have merged. The EIA is a US trade organization for the electronics industry that concentrates on hardware interface standards. Best known for the RS232C and RS422 standards that specify the electrical characteristics of interconnections between terminals and computers or between two computers.
- EIA/TIA 568 The EIA/TIA's most famous standard specifying a maximum horizontal cable run of 90 meters, allowing 10 meters for hub and device attachment resulting a total cable length of 1000 meters. Its related Service Bulletins TSB 36 and 40 define three categories of cabling system for data communications: Categories 3, 4 & 5.
- EISA (Extended Industry Standard Architecture) A 32-bit adaptation of the 8/16-bit buses originally developed by IBM and now standard in almost all PCs that use Intel's 8086 and 80X86 chips. The EISA bus is a joint development from Compaq and other PC manufacturers. Contrast with Microchannel and ISA.
- Electronic mail, e-mail The electronic transmission and reception of messages and text-based information without the need for the recipient to be present at the time of the transmission. Available either as a value-added service from providers such as GEIS, IBM and MCI or on LAN systems such as ccMail. De jure standards are evolving, but gateway software in the interim is now sufficiently mature to cope with most interactivity.
- EMI Electromagnetic Interference
- EMS (Element Management System) The level of a network management system concerned with collecting network management information from, and setting parameters on the network elements. Network elements consist of data communications and telecommunications equipment.
- Emulation Hardware or software, or a combination of the two, that behaves like another device or program, like PCs emulating dumb terminals.
- Encapsulation The process of sending data encoded in one protocol format across a network operating a different protocol, where it is not possible or desirable to convert between the two protocols. For example, where Ethernet LANs attach to an FDDI backbone, it is not possible to convert between the different packet formats, so the Ethernet packet is encapsulated in its entirety inside an FDDI packet as it crosses the bridge on to the FDDI network. When the encapsulated Ethernet packet reaches the bridge connecting the destination Ethernet LAN to the FDDI network, the Ethernet packet is stripped out of the FDDI packet and put, unchangedd on to the destination Ethernet LAN. Also known as protocol tunneling.
- Entry point An IBM network management term. An entry point provides management functions for itself and the devices attached to it. It has to be an SNA-addressable unit, allowing it to participate in network management by monitoring its own environment and exchanging information and messages with a Focal point.
- EPD End_of_Packet delimiter
- EPRI Electric Power Research Institute, Parlo Alto.
Electricity is increasingly recognized as a key to societal progress throughout the world driving economic prosperity and improving the quality of life. The Electric Power Research Institute delivers the science and technology to make the generation, delivery, and use of electricity affordable efficient and environmentally sound.
Created by the nation's electric utilities in 1973, EPRI is one of America's oldest and largest research consortia, with some 700 members and an annual budget of about $500 million. Linked to a global network of technical specialists, EPRI scientists and engineers develop innovative solutions to the world's toughest energy problems while expanding opportunities for a dynamic industry.
EPRI has initiated and supported the development of UCATM. "UCA" is a Trademark of EPRI, Palo Alto, USA
Electric Power Research Institute
3412 Hillview Avenue P.0. Box 10412
Palo Alto, CA 94303
- Error control A means of ensuring that information received across a transmission link is correct. The techniques involved typically use error detection to detect if the transmitted data has been corrupted. The error control technique involves asking for data to be retransmitted until a correct version is received.
- Error correction A technique to restore data integrity in received data that has been corrupted during transmission. Error correction techniques involve sending extra data along with the original data being sent. It allows the correct form of the data to be reconstructed from the extra information if the original has been corrupted. This extra information is calculated using particular error correction algorithms such as Hamming Code. It allow errors to be detected and the original data reconstructed. This is sometimes termed forward error correction.
- Error detection A set of techniques that can be used to detect errors in received data. Techniques that are applicable include parity checks involving parity bits, checksums or a Cyclic Redundancy Check.
- ESD end of stream delimiter
- Ethernet The most widely LAN transmission network. Based on a bus network topology, it runs at a maximum 10Mbit/s - in practice far less - and adopts CSMA/CD techniques operating over convention co-axial cable, thin wire co-axial cable and unshielded twisted pair cabling. A fiber-optic implementation has also been defined. Originally developed by Xerox, Intel and Dec, Ethernet has moved through V1 and V2 proprietary definitions, and has now been standardized by the IEEE as the IEEE 802.3 standard. This has several implementations - 10Base5 for use over conventional co-axial cable, 10BaseF for use over optic fiber, and 10BaseT for use over Unshielded Twisted Pair (UTP) cabling.
- Ethernet switching A technique inspired by Kalpana bringing the advantages of a parallel networking architecture to current contention- based Ethernet LANs. Each LAN can be segmented, each with its own 10Mbit/s path. When users on different segments exchange data, an Ethernet switch dynamically connects the two separate Ethernet channels without interfering with other network segments. The switch can create multiple independent connections between separate segments, allowing multiple parallel data exchanges. This multiplies network bandwidth without modification to Ethernet end station hardware or software. Once disparaged by other vendors, it now forms part of the portfolio of the major hub and router manufacturers.
- ETSI (European Telecommunications Standards Institute) A European standards body established in 1988 by a decision of the CEPT. It has taken over the work of the CEPT the area of developing the Net-Normes Europeene de Telecommunication, Net standards.
- Eutelsat Inter-governmental organization founded in 1983 with the launch of Eutelsat 1, Eutelsat aims to provide and operate a space segment for public intra-European international telecommunications services. The segment is also used to meet domestic needs by offering leased capacity, primarily for television. UK and France are the main shareholders, with about 25 members in total.
- EWOS (European Workshop for Open Systems) A forum aimed at promoting OSI standards and undertaking the development of functional profiles. Its work includes OSI Layers One to Four, FTAM, MHS, ODA, Directory Services and the VT protocol.