5/26/05 Glossary
OL-7426-03
Disable
Obsolete reference to the Exclusion List.
Diversity Antenna
A type of antenna system that uses two antennas to maximize reception and transmission quality and
reduce interference.
DMZ
Demilitarized Zone. A network layer added between the outside network (least secure) and internal
network (most secure) in order to add an extra level of security protection. Many companies choose to
locate Wireless Controllers, mail servers, Web servers, and remote access servers in the DMZ.
DNS
A program that translates URLs to IP Addresses by accessing a database maintained on a collection of
Internet servers. The program works behind the scenes to facilitate surfing the Web with alpha versus
numeric addresses. A DNS server converts a name like mywebsite.com to a series of numbers like
107.22.55.26. Every website has its own specific IP Address on the Internet.
DOS Attacks
Denial of Service Attacks. A network attack that creates enough congestion to block normal traffic.
DSCPDSCP
Differentiated Services Code Point. A packet header code from 0 - 63 that can be used to define quality
of service across the Internet.
DSL
Various technology protocols for high-speed data, voice and video transmission over ordinary
twisted-pair copper POTS (Plain Old Telephone Service) telephone wires.
DSSSDSSS
Direct Sequence Spread Spectrum. A carrier modulation technique used for 802.11b transmissions.
DTIMDTIM
Delivery Traffic Indication Map. A part of the TIM element in 802.11 beacons when a client has frames
buffered in the AP for broadcasting or multicasting. The buffered frames are broadcasted or multicasted
at each DTIM, when all power-saving clients expecting this data should be awake. See also TIM.
Dynamic Encryption Keys
Regularly-refreshed encryption keys. Used in LEAP and WPA protocols to decrease the ability to decrypt
the encoded data.
EAP
Extensible Authentication Protocol. Used under 802.1X framework as a PPP extension to provide addi-
tional authentication options.
EIRP
Effective Isotropic Radiated Power. The equivalent transmitted signal power relative to a hypothetical
isotropic (omnidirectional) radiator, measured in dBi (decibels isotropic).
Encryption
A method of scrambling data to maintain privacy.