Agilent Technologies AuroraPresto, User Manual

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Glossary & Abbreviations
Issue 7 - 05/02 Glossary-3
A B C D E F G H I
J K
L N O P Q R S T U V W X
Y Z
AIS
Alarm Indication Signal - an all ones signal sent down
or up stream by a device when:
• it detects an error condition,
• receives an error condition
• receives an error notification from another unit in
the transmission path.
ANSI
American National Standards Institute - the national
co-ordinating organisation for voluntary standards in
the US.
ATM
Asynchronous Transfer Mode - a form of digital
transmission based on the
Switching of fixed-length
units of information known as cells. It is suitable for
the transmission of image, voice, video and data.
ATM Layer
The protocol layer that relays cells from one ATM
node to another. It handles most of the processing and
routing activities including:
•
Switching
• multiplexing/demultiplexing
• operation and maintenance of virtual circuits
• traffic shaping and congestion control
ATM25
As defined by the ATM Forum. This is a 25.6 Mbits/p
cell-based user interface based on the IBM token ring
network.
ATU-C & ATU-R
ADSL Transmission Unit, Central or Remote. This is a
device at the end of an ADSL line between the
subscriber premises (ATU-R) or a telephone switch
(ATU-C).
B
Bandwidth
A measure of the throughput of a system or network.
Baud Rate
The number of line signal transitions per second - or
the rate at which data is transmitted over the serial
port.
481801-7.book Page 3 Thursday, May 23, 2002 10:46 AM