Instruction manual

DEFINITY® Business Communications System and GuestWorks® Issue 6
Overview
555-231-208
Issue 1
April 2000
Glossary and Abbreviations
GL-33
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
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.
TCP/IP
Transfer control protocol/internet protocol
TDM
See time-division multiplexing (TDM)
.
TDR
Time-of-day routing
TEG
Terminating extension group
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
.
time interval
The period of time, either one hour or one-half hour, that BCMS measurements are collected for a
reports.
time-out tone
Tones that indicate the user failed to dial within the preset time interval after lifting the handset or
after dialing the previous digit.