Glossary
GL-2 Issue 8.0 July 2002
Add/Drop-Rings Terminal Platform
The SONET standards that are implemented in the FT-2000 OC-48 Lightwave System. More
specifically, it is where one or more low speed shelfs are interconnected to either one Enhanced
high speed shelf (2-fiber ring) or two Enhanced high speed shelfs (4-fiber ring). And, where any slot
on the low speed shelf may be provisioned to have its traffic added/dropped from either the East or
West OC-48 high speed links.
AGNE
Alarm Gateway Network Element — A network element that receives remote network element
status information from other network elements in an alarm group and rebroadcasts the information
to all network elements in the alarm group. Using AGNEs makes it unnecessary for each network
element in the alarm group to communicate directly with all other network elements in the alarm
group.
AID
Access Identifier — A unique identifier used to address circuit pack slots, ports, and tributaries.
AIS
Alarm Indication Signal — A maintenance signal transmitted downstream in a digital network that
shows that an upstream failure has been detected and alarmed by some upstream equipment, if the
upstream alarm has not been suppressed.
Alarm
A contact closure to the office alarm grid.
Alarm Group
A group of network elements that share remote alarm information through an alarm gateway
network element (AGNE). Also refer to AGNE. The maximum size of an alarm group is 32 network
elements.
AMI
Alternate Mark Inversion — A line code that employs a ternary signal to convey binary digits, in
which successive binary ones are represented by signal elements that are normally of alternating,
positive, and negative polarity but equal in amplitude, and in which binary zeros are represented by
signal elements that have zero amplitude.
ANSI
American National Standards Institute — An organization consisting of producer, consumer, and
general interest groups that establishes the procedures by which accredited organizations create
and maintain voluntary industry standards in the United States.
APD
Avalanche Photodiode — A highly sensitive optical detector.
APS
Automatic Protection Switch — a protection switch that occurs in response to an automatically
detected trouble condition.
AS&C
Alarm, Status, and Control.
ASCII
American Standard Code for Information Interchange — A standard 8-bit code used for exchanging
information among data processing systems and associated equipment.
ASN.1
Abstract Syntax Notation 1.