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Cisco ONS 15454 Installation and Operations Guide
November 2001
AppendixD Glossary
Telcordia
Telcordia Technologies, Inc., formerly named Bellcore. Eighty percent of the U.S. telecommunications
network depends on software invented, developed, implemented, or maintained by Telcordia.
TID
Target Identifier. Identifi es the particular network element (in th is case, the ONS 15454) where each TL1
command is directed. The TID is a unique name given to each system at installation.
TLS
Transparent LAN Service. Provides private network service across a SONET backbone.
Transponder
Optional devices of a DWDM system providing the conversion of one opt ical wavelength to a precision
narrow band wavelength.
Trap
Message sent by an SNMP agent to an NMS (CTM), console, or terminal to indicate the occurrence of
a significant event, such as an exceeded threshold.
Tributary
The lower-rate signal directed into a multiplexer for combination (multiplexing) with other low rate
signals to form an aggregate higher rate level.
Trunk
Network traffic travels across this physical and logical connection between two switches. A backbone
is composed of a number of trunks. See also Backbone.
Tunneling
Architecture that is designed to provide the services necessary to implement any stand ard point-t o-poin t
encapsulation scheme. See also encapsulation.
U
Unicast
The communication of a single source to a single destination.
UPSR
Unidirectional Path Switched Ring. Path-switched SONET rings that employ redundant, fiber- optic
transmission facilities in a pair configuration. One fiber transmits in one direction and the backup fiber
transmits in the other. If the primary ring fails, the backup takes over.
Upstream
Set of frequencies used to send data from a subscriber to the headend.