DEFINITY ECS Release 8.2
Administrator’s Guide
555-233-506 Issue 1
April 2000
Glossary and abbreviations
1658
system manager
A person responsible for specifying and administering features and services for a system.
system reload
A process that allows stored data to be written from a tape into the system memory (normally after a power
outage).
T
T1 A digital transmission standard that in North America carries traffic at the DS1 rate of 1.54 4 Mbps. A T1
facility is divided into 24 channels (DS0s) of 64 kbps. These 24 channels, with an overall digital rate of 1.536
Mbps, and an 8-kbps framing and synchronization channel make up the 1.544-Mbps tran smission. When a
D-channel is present, it occupies channel 24. T1 facilities are also used in Japan and some Middle-Eastern
countries.
TAAS

Trunk Answer from Any Station

TABS

Telemetry asynchronous block serial

TAC
Trunk-access code
tandem switch
A switch within an electronic tandem network (ETN) that provides the logic to determine the best route for a
network call, possibly modifies the digits outpulsed, and allows or denies certain calls to cert ai n users.
tandem through
The switched connection of an incoming trunk to an outgoing trunk without human intervention.
tandem tie-trunk network (TTTN)
A private network that interconnects several customer switching systems.
TC Technical consultant
TCM

Traveling class mark

TDM

See time-division multiplexing (TDM).

TDR

Time-of-day routing

TEG
Terminating extension group
terminal
A device that sends and receives data within a system. See also administration terminal.
tie trunk
A telecommunications channel that directly connects two private switching systems.