CCNA Cisco Certified Network Associate Study Guide - FTP Server

674 Glossary
ELAN Emulated LAN: An ATM network configured using a client/server
model in order to emulate either an Ethernet or Token Ring LAN. Multiple
ELANs can exist at the same time on a single ATM network and are made
up of an LAN emulation client (LEC), an LAN Emulation Server (LES), a
Broadcast and Unknown Server (BUS), and an LAN Emulation Configuration
Server (LECS). ELANs are defined by the LANE specification. See also:
LANE, LEC, LECS, and LES.
ELAP EtherTalk Link Access Protocol: In an EtherTalk network, the linkaccess
protocol constructed above the standard Ethernet Data Link layer.
encapsulation 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.
encryption The conversion of information into a scrambled form that
effectively disguises it to prevent unauthorized access. Every encryption
scheme uses some well-defined algorithm, which is reversed at the receiving
end by an opposite algorithm in a process known as decryption.
Enhanced IGRP Enhanced Interior Gateway Routing Protocol: An
advanced routing protocol created by Cisco, combining the advantages of
link-state and distance-vector protocols. Enhanced IGRP has superior convergence
attributes, including high operating efficiency. See also: IGP,
OSPF, and RIP.
enterprise network A privately owned and operated network that joins
most major locations in a large company or organization.
EPROM Erasable Programmable Read-Only Memory: Programmed after
their manufacture, these nonvolatile memory chips can be erased if necessary
using high-power light and reprogrammed. See also: EEPROM, PROM.
ESF Extended Superframe: Made up of 24 frames with 192 bits each, with
the 193rd bit providing other functions including timing. This is an
enhanced version of SF. See also: SF.