E-commerce
Electronic commerce. Doing business online. Also called e-business and e-tailing, it involves making purchases via the Web. It includes electronic data interchange (EDI), in which one company's computer transmits purchase orders or other transactions to another company's computer. See EDI.
E1 Line
A 2.048-Mbps line that supports 32 64-Kbps channels, each of which can transmit and receive data or digitized voice. The line uses framing and signaling to achieve synchronous and reliable transmission. The most common configurations for E1 lines are E1 PRI and unchannelizes E1.
E1 PRI line
An ISDN line that consists of 32 64 kbps channels. This type of line uses 30 B channels for user data, 164 kbps D channel for ISDN D-channel signaling, and one framing channel. The B channels can be all switched, all nailed up, or a combination of switched and nailed up. This type of PRI line is a standard in Europe and Asia called CEPT G.703.
E2000
A type of optical connector. Trademarked by Diamond, Inc.
EDFA
Erbium-Doped Fiber Amplifier
EEPROM
Electronically Erasable Programmable Read-Only Memory
EGP
Exterior Gateway Protocol
ENIGMA
ENIGMA is an important provider of network security applications. SafeWord AStm is a software authentication server that identifies users with dynamic passwords prior to the granting of access. This UNIX-based program identifies users at the point of connection to a TCP/IP network, and utilizes standard network authentication protocols.
ESF
Extended Super Frame. A T1 framing format.
ETHERIP
Ethernet-within-IP Encapsulation
Earth Station
A ground based antenna system that is used to send or receive signals to or from a satellite.
Echo
A signal that determines whether a node can receive and acknowledge data transmissions. A host sends an echo request packet. if the destination is properly connected and receives the echo request packet, it sends back an echo reply packet.
Echo Cancellation
A method the telephone company uses to remove echoes from an analog line.
Echo Canceller
A chip that identifies and erases echoes in satellite and terrestrial long-distance phone calls.
Electromagnetic Interference (EMI)
Electromagnetic interference caused by a conductor.
Electron
An elementary particle made of a tiny charge of negative electricity. Electron holes are the holes that are left when electrons are taken from an element. Bound electrons are electrons that have been attracted into electron holes. Both electron holes and an extra electron (as in n-type silicon) enable electric current to flow.
Electron Beam (E-beam) System
A device that generates a stream of electrons that print circuit features on silicon chips. Bell Labs SCALPEL is an electron beam lithography system.
Electron Flow
In semiconductors electrons flow only from n-type silicon to p-type silicon because the electrons in the n-type are attracted to the holes in the p-type, which allows conventional current to flow in the opposite direction. See for details.
Electronic Content Distribution
The distribution of text or image in an electronic format that allows the content to be processed or edited. Compare to facsimile, which distributes a graphic representation of the contents rather than the contents themselves.
Electronic Data Interchange (EDI)
The electronic transmission of business transactions, such as orders, confirmations and invoices, between and within companies. See also E-commerce.
Electronic Industries Association (EIA)
A standards organization for the electronics industry. Known for the RS232C and RS422 standards that specify the electrical characteristics of interconnections between terminals and computers or between.
Electronic messaging
The transmission of messages over a network, sometimes called e-mail. E-mail requires a messaging system, which provides a store and forward capability, plus a mail program that lets the user access the system to send and receive messages.
Email
Electronic mail. Electronic messages, usually text, sent from one person's computer to another's. Email can also be broadcast automatically to a large number of addresses.
Emitter
One side of a transistor. In a NPN transistor the electrons flow from emitter to collector. In a PNP transistor the electrons flow from collector to emitter. See ezine for details.
Encapsulating Security Payload (ESP)
A provision of IPSec that encrypts and decrypts IP packets. The payload itself can be either the entire original packet (tunnel mode), or just the data portion (transport mode). The cryptography process is controlled by keys of various lengths employed in a variety of different algorithms.
Encapsulation
Encapsulating data is a technique used by layered protocols in which a low level protocol accepts a message from a higher level protocol, then places it in the data portion of the lower-level frame. The logistics of encapsulation require that packets traveling over physical network contain a sequence of headers. The first header derives from the physical network frame, the second from the IP frame, the third from the physical network frame, and so on. Encapsulation enables the transmission of data over different network portions based on differing protocols.
Encryption
The conversion of data into a secret code for transmission over a public network. The original text, or plain text, is converted into a coded equivalent called cipher text via an encryption algorithm. The cipher text is decoded (decrypted) at the receiving end and turned back into plain text.
End-to-end Delay
An asynchronous transfer mode (ATM) routing metric that measures the time it takes a cell to get from one end of a connection to the other.
Endpoint
When a tunneling protocol is in use, the system that encapsulates the packets (the foreign agent) or the system that decapsulates the packets (the tunnel server).
Enet Number
In IPX network, this number is analogous to a network address for an IP network.
Enterprise Computer Telephony Forum (ECTF)
Enterprise Computer Telephony Forum.
Enterprise Network
An information infrastructure, often combining private and public facilities, to cover all of the locations operated by a single company or corporate enterprise with a single communications fabric.
Enterprise-wide Network
A network that contains all or most of a company’s hardware and software resources. Typically, an enterprise-wide network includes computers that run different operating systems and reside on different types of networks. Therefore, achieving interoperability is the biggest challenge facing the administrator of an enterprise-wide network.
Environment Variable
A system-or user-defined variable that provides information to the UNIX shell about the operating environment.
Epoch Date
A point in history in which time is measured. The Internet uses Jan 1, 1900.
Erbium-Doped Fiber Amplifier
Means of fiber optic amplification. The transmitted light signal is passed through a section of fiber doped with erbium, a rare earth element, and is amplified by a pump diode.
Error Correction
A process that determines whether line noise has caused data to be garbled or dropped in transit, and then works to correct the problem. The two most common error-correction protocols and standards used by analog modems are MNP and V.42.
Error Detection And Correction (EDAC)
EDAC is a method of determining whether transmission errors have occurred. In the event of an error. EDAC makes the necessary corrections.
Etch
In semiconductor production, the process by which materials such as oxide are removed from a wafer by subjecting it to a chemical, electrolytic or plasma (ion bombardment) process. See ezine for details.
Ethernet
A local area network that connects devices like computers, printers, and terminals. Ethernet operates over twisted-pair or coaxial cable at speeds at 10 or 100 Mbps.
Ethernet II
A protocol specification for the media access control (MAC) header of an IPX frame.
Ethernet Packet
A variable-length unit of data transmitted on an Ethernet LAN.
Ethernet transceiver
An Ethernet device that connects workstations to standard thick or thin Ethernet-style cable. This device sends and receives information and often offers data packet collision detection.
Ethernet-within-IP Encapsulation
Ethernet-within-IP Encapsulation.
Ethernet_II Frame
The only difference with an Ethernet_II frame is in the MAC header. Where the 2 bytes following the Source MAC Address are interpreted as the "length" bytes in an 802.3 frame, the Ethernet_II frame defines these two bytes as a "type" description instead. If the decimal value of these two hex bytes come out to a number greater than 1500, then you know this is an Ethernet_II frame.
European Telecommunications Standards Institute
An international standards body that recommends standards for telephony, ISDN, wireless, and synchronous transport in Europe.
Excess Burst (Be)
Be is the maximum number of bits of uncommitted data, in excess of the Committed Burst (Bc) size, that the network attempts to deliver during the time interval specified by Tc. In general, Be is delivered with a lower probability than Bc.
Exclusive Port Routing
A feature that causes the Lucent unit to drop calls for which it has no explicit call-routing information (such as answer numbers and ISDN subaddressing). When exclusive port routing is disabled (the default), and the bearer service is voice, the Lucent unit routes the call to a digital modem. If the bearer service is V.110, the Lucent unit routes the call to the first available V.110 module. If the bearer service is data, the Lucent unit routes the call to the first available AIM port. If no AIM port is available, the Lucent unit routes the call to the bridge/router.
Expansion Protocol Option Device (XPOD)
An XPOD is a protocol option device (POD) attached to the interface control module (ICM) of a Lucent broadband access device. The XPOD provides such interface capabilities as asynchronous transfer mode (ATM) wide-area connections and circuit switching.
Explicit Congestion Notification (ECN)
ECN is a method of informing framing relay nodes that there is traffic congestion on the network. The frame relay header can use a backward explicit congestion notification (BECN) bit or a forward explicit congestion notification (FECN) bit to notify nodes of traffic congestion.
Explicit Forward Congestion Indication (EFCI)
in asynchronous transfer mode (ATM), EFCI is a field in a cell header. The EFCI field is set to notify the destination device of a nearly congested or fully congested network condition.
Extended AppleTalk Network
An AppleTalk Phase 2 network that uses an extended addressing scheme. With extended addressing, AppleTalk uses an 8-bit node number and a 16-bit network number for each host, allowing up to 16 million hosts on one network
Extended Super Frame
ESF is a framing format that consists of 24 consecutive frames separated by framing bits. The ISDN specification advised that you use ESF with ISDN D-channel signaling.
External Data Representation (XDR)
The standard for a machine independent data structure representation developed by researchers at Xerox Corporation. Although similar in spirit to DARPA Internet Protocols, XNS uses different packet formats and terminology’s.
External Modulation
Modulation of a light source by an external device such as a interferometric or electo-absorbtive modulator
External Route
A route imported into the Open Shortest Path First (OSPF) database from outside the router’s Autonomous System (AS).
External Testing
A loopback test that diagnoses the ability of the port to send and receive data.
Extranet
A VPN for existing customers and suppliers rather than the general public. It can provide access to paid research, current inventories and internal databases, virtually any information that is private and not published for everyone. An extranet uses the public Internet as its transmission system, but requires passwords to gain access.
Electronic commerce. Doing business online. Also called e-business and e-tailing, it involves making purchases via the Web. It includes electronic data interchange (EDI), in which one company's computer transmits purchase orders or other transactions to another company's computer. See EDI.
E1 Line
A 2.048-Mbps line that supports 32 64-Kbps channels, each of which can transmit and receive data or digitized voice. The line uses framing and signaling to achieve synchronous and reliable transmission. The most common configurations for E1 lines are E1 PRI and unchannelizes E1.
E1 PRI line
An ISDN line that consists of 32 64 kbps channels. This type of line uses 30 B channels for user data, 164 kbps D channel for ISDN D-channel signaling, and one framing channel. The B channels can be all switched, all nailed up, or a combination of switched and nailed up. This type of PRI line is a standard in Europe and Asia called CEPT G.703.
E2000
A type of optical connector. Trademarked by Diamond, Inc.
EDFA
Erbium-Doped Fiber Amplifier
EEPROM
Electronically Erasable Programmable Read-Only Memory
EGP
Exterior Gateway Protocol
ENIGMA
ENIGMA is an important provider of network security applications. SafeWord AStm is a software authentication server that identifies users with dynamic passwords prior to the granting of access. This UNIX-based program identifies users at the point of connection to a TCP/IP network, and utilizes standard network authentication protocols.
ESF
Extended Super Frame. A T1 framing format.
ETHERIP
Ethernet-within-IP Encapsulation
Earth Station
A ground based antenna system that is used to send or receive signals to or from a satellite.
Echo
A signal that determines whether a node can receive and acknowledge data transmissions. A host sends an echo request packet. if the destination is properly connected and receives the echo request packet, it sends back an echo reply packet.
Echo Cancellation
A method the telephone company uses to remove echoes from an analog line.
Echo Canceller
A chip that identifies and erases echoes in satellite and terrestrial long-distance phone calls.
Electromagnetic Interference (EMI)
Electromagnetic interference caused by a conductor.
Electron
An elementary particle made of a tiny charge of negative electricity. Electron holes are the holes that are left when electrons are taken from an element. Bound electrons are electrons that have been attracted into electron holes. Both electron holes and an extra electron (as in n-type silicon) enable electric current to flow.
Electron Beam (E-beam) System
A device that generates a stream of electrons that print circuit features on silicon chips. Bell Labs SCALPEL is an electron beam lithography system.
Electron Flow
In semiconductors electrons flow only from n-type silicon to p-type silicon because the electrons in the n-type are attracted to the holes in the p-type, which allows conventional current to flow in the opposite direction. See for details.
Electronic Content Distribution
The distribution of text or image in an electronic format that allows the content to be processed or edited. Compare to facsimile, which distributes a graphic representation of the contents rather than the contents themselves.
Electronic Data Interchange (EDI)
The electronic transmission of business transactions, such as orders, confirmations and invoices, between and within companies. See also E-commerce.
Electronic Industries Association (EIA)
A standards organization for the electronics industry. Known for the RS232C and RS422 standards that specify the electrical characteristics of interconnections between terminals and computers or between.
Electronic messaging
The transmission of messages over a network, sometimes called e-mail. E-mail requires a messaging system, which provides a store and forward capability, plus a mail program that lets the user access the system to send and receive messages.
Electronic mail. Electronic messages, usually text, sent from one person's computer to another's. Email can also be broadcast automatically to a large number of addresses.
Emitter
One side of a transistor. In a NPN transistor the electrons flow from emitter to collector. In a PNP transistor the electrons flow from collector to emitter. See ezine for details.
Encapsulating Security Payload (ESP)
A provision of IPSec that encrypts and decrypts IP packets. The payload itself can be either the entire original packet (tunnel mode), or just the data portion (transport mode). The cryptography process is controlled by keys of various lengths employed in a variety of different algorithms.
Encapsulation
Encapsulating data is a technique used by layered protocols in which a low level protocol accepts a message from a higher level protocol, then places it in the data portion of the lower-level frame. The logistics of encapsulation require that packets traveling over physical network contain a sequence of headers. The first header derives from the physical network frame, the second from the IP frame, the third from the physical network frame, and so on. Encapsulation enables the transmission of data over different network portions based on differing protocols.
Encryption
The conversion of data into a secret code for transmission over a public network. The original text, or plain text, is converted into a coded equivalent called cipher text via an encryption algorithm. The cipher text is decoded (decrypted) at the receiving end and turned back into plain text.
End-to-end Delay
An asynchronous transfer mode (ATM) routing metric that measures the time it takes a cell to get from one end of a connection to the other.
Endpoint
When a tunneling protocol is in use, the system that encapsulates the packets (the foreign agent) or the system that decapsulates the packets (the tunnel server).
Enet Number
In IPX network, this number is analogous to a network address for an IP network.
Enterprise Computer Telephony Forum (ECTF)
Enterprise Computer Telephony Forum.
Enterprise Network
An information infrastructure, often combining private and public facilities, to cover all of the locations operated by a single company or corporate enterprise with a single communications fabric.
Enterprise-wide Network
A network that contains all or most of a company’s hardware and software resources. Typically, an enterprise-wide network includes computers that run different operating systems and reside on different types of networks. Therefore, achieving interoperability is the biggest challenge facing the administrator of an enterprise-wide network.
Environment Variable
A system-or user-defined variable that provides information to the UNIX shell about the operating environment.
Epoch Date
A point in history in which time is measured. The Internet uses Jan 1, 1900.
Erbium-Doped Fiber Amplifier
Means of fiber optic amplification. The transmitted light signal is passed through a section of fiber doped with erbium, a rare earth element, and is amplified by a pump diode.
Error Correction
A process that determines whether line noise has caused data to be garbled or dropped in transit, and then works to correct the problem. The two most common error-correction protocols and standards used by analog modems are MNP and V.42.
Error Detection And Correction (EDAC)
EDAC is a method of determining whether transmission errors have occurred. In the event of an error. EDAC makes the necessary corrections.
Etch
In semiconductor production, the process by which materials such as oxide are removed from a wafer by subjecting it to a chemical, electrolytic or plasma (ion bombardment) process. See ezine for details.
Ethernet
A local area network that connects devices like computers, printers, and terminals. Ethernet operates over twisted-pair or coaxial cable at speeds at 10 or 100 Mbps.
Ethernet II
A protocol specification for the media access control (MAC) header of an IPX frame.
Ethernet Packet
A variable-length unit of data transmitted on an Ethernet LAN.
Ethernet transceiver
An Ethernet device that connects workstations to standard thick or thin Ethernet-style cable. This device sends and receives information and often offers data packet collision detection.
Ethernet-within-IP Encapsulation
Ethernet-within-IP Encapsulation.
Ethernet_II Frame
The only difference with an Ethernet_II frame is in the MAC header. Where the 2 bytes following the Source MAC Address are interpreted as the "length" bytes in an 802.3 frame, the Ethernet_II frame defines these two bytes as a "type" description instead. If the decimal value of these two hex bytes come out to a number greater than 1500, then you know this is an Ethernet_II frame.
European Telecommunications Standards Institute
An international standards body that recommends standards for telephony, ISDN, wireless, and synchronous transport in Europe.
Excess Burst (Be)
Be is the maximum number of bits of uncommitted data, in excess of the Committed Burst (Bc) size, that the network attempts to deliver during the time interval specified by Tc. In general, Be is delivered with a lower probability than Bc.
Exclusive Port Routing
A feature that causes the Lucent unit to drop calls for which it has no explicit call-routing information (such as answer numbers and ISDN subaddressing). When exclusive port routing is disabled (the default), and the bearer service is voice, the Lucent unit routes the call to a digital modem. If the bearer service is V.110, the Lucent unit routes the call to the first available V.110 module. If the bearer service is data, the Lucent unit routes the call to the first available AIM port. If no AIM port is available, the Lucent unit routes the call to the bridge/router.
Expansion Protocol Option Device (XPOD)
An XPOD is a protocol option device (POD) attached to the interface control module (ICM) of a Lucent broadband access device. The XPOD provides such interface capabilities as asynchronous transfer mode (ATM) wide-area connections and circuit switching.
Explicit Congestion Notification (ECN)
ECN is a method of informing framing relay nodes that there is traffic congestion on the network. The frame relay header can use a backward explicit congestion notification (BECN) bit or a forward explicit congestion notification (FECN) bit to notify nodes of traffic congestion.
Explicit Forward Congestion Indication (EFCI)
in asynchronous transfer mode (ATM), EFCI is a field in a cell header. The EFCI field is set to notify the destination device of a nearly congested or fully congested network condition.
Extended AppleTalk Network
An AppleTalk Phase 2 network that uses an extended addressing scheme. With extended addressing, AppleTalk uses an 8-bit node number and a 16-bit network number for each host, allowing up to 16 million hosts on one network
Extended Super Frame
ESF is a framing format that consists of 24 consecutive frames separated by framing bits. The ISDN specification advised that you use ESF with ISDN D-channel signaling.
External Data Representation (XDR)
The standard for a machine independent data structure representation developed by researchers at Xerox Corporation. Although similar in spirit to DARPA Internet Protocols, XNS uses different packet formats and terminology’s.
External Modulation
Modulation of a light source by an external device such as a interferometric or electo-absorbtive modulator
External Route
A route imported into the Open Shortest Path First (OSPF) database from outside the router’s Autonomous System (AS).
External Testing
A loopback test that diagnoses the ability of the port to send and receive data.
Extranet
A VPN for existing customers and suppliers rather than the general public. It can provide access to paid research, current inventories and internal databases, virtually any information that is private and not published for everyone. An extranet uses the public Internet as its transmission system, but requires passwords to gain access.
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