Glossary
NUMERICS
1+1 (unidirectional)
The 1+1 optical line protection switching architecture protects against failures of the optical
transmit/receive equipment and their connecting fiber facility. One optical line (two fibers plus
associated OLIUs on each end) is designated
″
service,
″
and the other optical line is designated
″
protection.
″
In the transmit direction at each end, identical signals are bridged on the service
and protection lines (
″
dual-fed
″
). At each end, the receiving equipment monitors the incoming
service and protection lines independently, and selects traffic from one line (the
″
active
″
line)
based on performance criteria and technician/OS control. In unidirectional 1+1 both service and
protection lines could be active at the same time (service in one direction, protection in the
other).
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A
ABN
Abnormal (status condition)
AC
Alternating Current
Active
Active identifies a 1+1 protected OC-N line which is currently selected by the receiver at either
end as the payload carrying signal or a 1x1 or 1xN protected circuit pack that is currently
carrying service. (See Standby).
AGNE
Alarm Gateway Network Element
AIS
Alarm Indication Signal
Alarm
Visible or audible signal indicating that an equipment failure or significant event/condition has
occurred.
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365-372-333 R2.1
Issue 4, June 2005
Lucent Technologies
G L O S S A R Y
G L - 1
