D-Link Unified Access Point Administrator’s Guide
164 © 2001-2008 D-Link Corporation. All Rights Reserved.
802.11e
task group. A subset of
802.11e
features is
described in the
WMM
specification.
R
RADIUS
The Remote Authentication Dial-In User Service
(RADIUS) provides an authentication and
accounting system. It is a popular authentication
mechanism for many
ISP
s.
RC4
A symmetric stream cipher provided by
RSA
Security
. It is a variable key-size stream cipher with
byte-oriented operations. It allows keys up to 2048
bits in length.
Roaming
In
IEEE
802.11
parlance, roaming clients are mobile
client stations or devices on a wireless network
(
WLAN
) that require use of more than one
Access
Point
(AP) as they move out of and into range of
different base station service areas. IEEE
802.11f
defines a standard by which APs can communicate
information about client associations and
disassociations in support of roaming clients.
Router
A router is a network device which forwards packets
between networks. It is connected to at least two
networks, commonly between two local area
networks (
LAN
s) or between a
LAN
and a wide-area
network (
WAN
), for example, the Internet. Routers
are located at gateways—places where two or more
networks connect.
A router uses the content of headers and its tables to
determine the best path for forwarding a packet. It
uses protocols such as the Internet Control Message
Protocol (ICMP), Routing Information Protocol
(RIP), and Internet Router Discovery Protocol
(IRDP) to communicate with other routers to
configure the best route between any two hosts. The
router performs little filtering of data it passes.
RSSI
The Received Signal Strength Indication (RSSI) an
802.1X
value that calculates voltage relative to the
received signal strength. RSSI is one of several ways
of measuring and indicating radio frequency (RF)
signal strength. Signal strength can also be measured
in mW (milliwatts), dBms (decibel milliwatts), and a
percentage value.
RTP
Real-Time Transport Protocol (RTP) is an Internet
protocol for transmitting real-time data like audio
and video. It does not guarantee delivery but
provides support mechanisms for the sending and
receiving applications to enable streaming data. RTP
typically runs on top of the
UDP
protocol, but can
support other transport protocols as well.
RTS
A request to send (RTS) message is a signal sent by a
client station to the access point, asking permission
to send a data packet and to prevent other wireless
client stations from grabbing the radio waves. This
message is a part of the IEEE 802.11
CSMA/CA
protocol. (See also
RTS Threshold
and
CTS
.)
RTS Threshold
The RTS threshold specifies the packet size of a
request to send (
RTS
) transmission. This helps
control traffic flow through the access point, and is
especially useful for performance tuning on an access
point with a many clients.
S
Shared Key
A shared key is used in conventional encryption
where one key is used both for encryption and
decryption. It is also called secret-key or symmetric-
key encryption.
Also see
Public Key
.
SSID
The Service Set Identifier (SSID) is a thirty-two
character alphanumeric key that uniquely identifies a
