OxyGEN
mini
Office
Administrator’s Guide
ATM
Asynchronous Transfer Mode A standard for high-speed transmission of data,
text, voice, and video, widely used within the Internet.
ATM utilizes virtual
channels instead of dedicated circuits to carry data in fixed-length cells (1 cell =
53 bytes) over a broadband network with the corresponding data rates ranging
from 45 Mbps to 2.5 Gbps.
Attenuation
The reduction in amplitude and intensity of a signal as a consequence of its
transmission over a medium.
It is usually measured in decibels (dB) and the
greater the distance from the modem to the local telephone exchange, the
higher this value is likely to be.
Authentication
The process of verifying a user’s identity, such as by prompting for a password.
Auto-MDIX
Automatic Medium-Dependent Interface Crossover A technology that automat-
ically detects the required cable connection type (straight or crossover) and
configures the connection appropriately.
Bandwidth
1. The information carrying capacity of a channel. Expressed in hertz (e.g., kHz
or MHz) for analog transmission media and in bits per second (e.g. kbps, Mbps)
for digital transmission media.
Beacon Interval
The duration between beacon packets. Access Points broadcast Beacons in
order to synchronize wireless networks.
In a "noisy" environment - one with
much interference - decreasing the Beacon Interval may improve network
performance. In very remote locations (with few wireless nodes) this value may
be increased.
BER
Bit Error Rate
BER is the percentage of bits received with errors divided by the total number of
bits that have been received over a given time period.
Binary
The "base-two" system of numbers that uses only two digits, 0 and 1, to represent
all numbers.
In binary, the number 1 is written as 1, 2 as 10, 3 as 11, 4
as 100, etc.
Although expressed as decimal numbers for convenience, IP
addresses in actual use are binary numbers; e.g., the IP address 209.191.4.240 is
11010001.10111111.00000100.11110000 in binary.
See Bit, IP Address, Network Mask.
Bit
Short for "binary digit", a bit is a number that can have two values, 0 or 1.
See Binary.
Bit-swap
Bit-swapping is the essential adaptive hand-shaking mechanism used by DMT
modems to adapt to line changes (ADSL line noise increases).
Black-list
A list of numbers that are blocked from calling the local phone lines. Whenever,
a call originating from these numbers is received, it is automatically rejected.
Bps
Bits per second
BRAS
Broadband Remote Access Server
The BRAS sits at the core of an ISP’s network, and aggregates user sessions from
the access network. Beyond aggregation it is also the injection point for policy
management and IP QoS.
Gennet s.a.
211