Instruction manual

GLOSSARY
T
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 inter-
vention.
Tandem Tie Trunk Network (TTTN)
A private network that interconnects several customer switching systems by dial repeat-
ing tie trunks. Access to the various systems is dictated by codes that must be individu-
ally dialed for each system.
Tie Trunk
A telecommunications channel that directly connects two private switching systems.
Time Division Multiplex Bus
A special bus that is time shared by preallocating short time slots to each transmitter on
a regular basis. In a PBX, all port circuits are connected to the time division multiplex
bus permitting any port to send a signal to any other port.
Tone Ringer
A device with a speaker, used in electronic voice terminals to alert the user.
Trunk
A telecommunications channel between two switching systems.
Trunk Data Module (TDM)
Provides the required interface between the system and a data set (modem) or data ser-
vice unit connected to a private or switched data line.
Trunk Group
Telecommunications channels assigned as a group for certain functions.
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