Filter
Top Products
Glossary and Abbreviations
Issue 5 January 1998 GL-47555-230-024
T
T1
A digital transmission standard that in North America carries traffic at the DS1 rate of 1.544 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 transmission. 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 certain 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.
time-division multiplex (TDM) bus
A bus that is time-shared regularly by preallocating short time slots to each transmitter. In a PBX,
all port circuits are connected to the TDM bus, permitting any port to send a signal to any other
port.
time-division multiplexing (TDM)
Multiplexing that divides a transmission channel into successive time slots. See also multiplexing.