Dhcp, Supp, Serve – USRobotics Instant802 APSDK User Manual

Page 308: If no, Switch and, The switch and, Dtim

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Professional Access Point

Administrator Guide

Glossary - 308

D

DCF

The Distribution Control Function is a component of the IEEE 802.11e Quality of Service (QoS) technology
standard. The DCF coordinates channel access among multiple stations on a wireless network by
controlling wait times for channel access. Wait times are determined by a random backoff timer which is
configurable by defining minimum and maximum contention windows. See also

EDCF

.

DHCP

The Dynamic Host Configuration Protocol (DHCP) is a protocol specifying how a central server can
dynamically provide network configuration information to clients. A DHCP server offers a lease (for a pre-
configured period of time—see

Lease Time

) to the client system. The information supplied includes the

client's IP addresses and netmask plus the address of its

DNS

servers and

Gateway

.

DNS

The Domain Name Service (DNS) is a general-purpose query service used for translating fully-qualified
names
into Internet addresses. A fully-qualified name consists of the hostname of a system plus its domain
name. For example, www is the host name of a Web server and www.usr.com is the fully-qualified name of

that server. DNS translates the domain name www.usr.com to an IP address, for example 66.93.138.219.

A domain name identifies one or more IP addresses. Conversely, an IP address may map to more than
one domain name.

A domain name has a suffix that indicates which top level domain (TLD) it belongs to. Every country has its
own top-level domain, for example .de for Germany, .fr for France, .jp for Japan, .tw for Taiwan, .uk for

the United Kingdom, .us for the U.S.A., and so on. There are also .com for commercial bodies, .edu for

educational institutions, .net for network operators, and .org for other organizations as well as .gov for

the U. S. government and .mil for its armed services.

DOM

The Document Object Model (DOM) is an interface that allows programs and scripts to dynamically access
and update the content, structure, and style of documents. The DOM allows you to model the objects in an
HTML or XML document (text, links, , tables), defining the attributes of each object and how they can be
manipulated.

Further details about the DOM can be found at the

W3C

.

DTIM

The Delivery Traffic Information Map (DTIM) message is an element included in some

Beacon

frames. It

indicates which stations, currently sleeping in low-power mode, have data buffered on the

Access Point

awaiting pick-up. Part of the DTIM message indicates how frequently stations must check for buffered
data.

Dynamic IP Address

See

IP Address

.

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