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RSSI
Received Signal Strength Indicator, also known as Signal Strength. A measure of received RF energy,
measured in dBm.
RTOS
Real-time operating system. An operating system that features a guaranteed performance per time
unit.
Rx
Receive.
Satellite Broadband
A wireless high-speed Internet connection provided by satellites. Some satellite broadband connections
are two-way-up and down. Others are one-way, with the satellite providing a high-speed downlink and
then using a dial-up telephone connection or other land-based system for the uplink to the Internet.
Server
A computer that provides its resources to other computers and devices on a network. These include
print servers, Internet servers and data servers. A server can also be combined with a hub or router.
Site Survey
The process whereby a wireless network installer inspects a location prior to putting in a wireless
network. Site surveys are used to identify the radio- and client-use properties of a facility so that
access points can be optimally placed.
SNR
Signal to Noise Ratio. The ratio of signal intensity to noise intensity, measured in dB.
SOHO
A term generally used to describe an office or business with ten or fewer computers and/or employees.
SSH
Secure Shell; also known as Secure Socket Shell. SSH data transmissions and passwords to and from
Cisco 4100 Series Wireless LAN Controller are encrypted and use digital certificates for authentication
from both ends of the connection. SSH is always enabled for Cisco Wireless LAN Controllers.
When you plan to secure the Cisco Wireless LAN Controller Telnet Interface using the SSH protocol,
note that the Operating System automatically generates its own local SSH certificate and automatically
applies it to the Telnet Interface.
SSID
A 32-character unique identifier attached to the header of packets sent over a WLAN that acts as a
name when a mobile device tries to connect to an access point. (Also called ESSID.) The SSID differen-
tiates one WLAN from another, so all access points and all devices attempting to connect to a specific
WLAN must use the same SSID. A device will not be permitted to associate with the AP unless it can
provide the unique SSID. Because an SSID can be sniffed in plain text from a packet, it does not supply
any security to the network. An SSID is also referred to as a Network Name because essentially it is a
name that identifies a wireless network.