Alcatel-Lucent 1665 Installation Manual page 393

Terms and definitions
0x1
See Ring (0x1) Low-Speed Interface.
1+1
The 1+1 protection switching architecture protects against failures of the optical transmit/receive equipment
and their connecting fiber facility. One bidirectional interface (two fibers plus associated OLIUs on each
end) is designated "service," and the other is designated "protection." In each direction, identical signals are
transmitted on the service and protection lines ("dual-fed"). 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 1+1 both service and protection lines could be active at
the same time (service in one direction, protection in the other).
1xN, 1x1
1xN protection switching pertains to circuit pack protection that provides a redundant signal path through
the DMX 2.5G Multiplexer (it does not cover protection switching of an optical facility; se "1+1"). In 1xN
switching, a group of N service circuit packs share a single spare protection circuit pack. 1x1 is a special
case of 1xN, with N=1. In 1x1 only one is active at a time.
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A 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
A defined NE in an alarm group through which members of the alarm group exchange information.
AIS - Alarm Indication Signal
A code transmitted downstream in a digital network that shows that an upstream failure has been detected
and alarmed.
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.
ASCII - American Standard Code for Information Interchange
A standard 8-bit code used for exchanging information among data processing systems and associated
equipment.
Auto
One possible state of a service interface port. In this state, the port will automatically be put "in service" if
a good incoming signal is detected on the port.
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365-372-304R7.1
Issue 1, November 2007
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