Alcatel-Lucent 1665 Installation Manual page 401

Glossary
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Subnetwork
Group of SONET network elements that share a SONET data communications channel.
Synchronization Messaging
SONET synchronization messaging is used to communicate the quality of network timing, internal
timing status, and timing states throughout a subnetwork.
SYSCTL - System Controller
The system controller circuit pack that provides overall administrative control of the terminal.
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T
T1X1 and T1M1
The ANSI committees responsible for telecommunications standards.
TCA - Threshold Crossing Alert
A condition set when a performance monitoring counter exceeds a user-selected threshold. A TCA
does not generate an alarm but is available on demand through the CIT and causes a message to be
sent to NMA via the X.25/TL1 interface.
TL1 - Transaction Language 1
A Telcordia Technologies machine-to-machine communications language that is a subset of ITU-
TSS, formerly CCITT's, human-machine language.
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U
UAS - Unavailable Seconds
In performance monitoring, the count of seconds in which a signal is declared failed or, in which,
10 consecutively severely errored seconds (SES) occurred, until the time when 10 consecutive non-
SES occur.
Unidirectional
A protection switching mode in which the system at each end of an optical span monitors both
service and protection lines and independently chooses the best signal (unless overridden by an
equipment failure or by an external request, such as a forced switch or lockout). In a system that
uses unidirectional line switching, both the service and protection lines may be active
simultaneously, with one line carrying traffic in one direction and other line carrying traffic in the
other direction. For a 1+1 protection scheme the K1 and K2 bytes in the SONET line overhead are
used to convey to the far end which line the near-end receiver has chosen, so that an "active"
indication may be made at the far end.
UOC - Univeral Optical Connector
Receptacles on the faceplate of some OLIUs that accept ST, SC, or FC connectors.
UPD/INIT
A push-button on the SYSCTL faceplate.
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Alcatel-Lucent 1665 DMX R9.0
365-372-304R9.0 Issue 2
July 2010
Terms and definitions
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