Lucent Technologies Metropolis DMXplore, Руководство по установке

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G L O S S A R Y
G L - 2 8
365-372-334 R2.0
Issue 4, November 2004
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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.
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 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.
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.