GL-20
Issue 9 October 1998
363-206-204
GLOSSARY
TBOS
Telemetry Byte-Oriented Serial (Protocol) — Defines one physical interface for
direct connection between the telemetry remote and the monitored equipment. An
EIA RS-422 port is used to provide the operations system with sufficient alarm
and status information to localize a problem to a given DDM-2000 and to deter-
mine the severity of the problem.
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, is shown by TBOS and causes a mes-
sage to be sent to NMA via the X.25/TL1 interface.
TCVCXO
Temperature Compensated Voltage Controlled Crystal Oscillator — A highly sta-
ble and accurate clock source used in the DDM-2000 TGS circuit pack.
TGS
The timing generator circuit pack generates clock signals for distribution to the
transmit circuits. It operates in the free-running, loop timing, phase-lock, and hold-
over modes.
TID
Target Identifier — The Bellcore name for a system shelf.
TL1
Transaction Language 1 — A Bellcore machine-to-machine communications lan-
guage that is a subset of ITU’S (formerly CCITT) human-machine language.
TMUX
Trans-mux or trans-multiplex. The new TMUX circuit pack (BBG20) provides path
termination functions for an M13 or C-bit parity DS3 signal. It demultiplexes the
DS3 into 28 DS1s, performs DS1 PM, maps each DS1 into a VT1.5, and multi-
plexes the 28 VT1.5s into an STS-1.
TOP
Task Oriented Practice.
TR
Bellcore Technical Requirement
TSA
Time Slot Assignment.
TSI
Time Slot Interchange.