Instruction manual

DEFINITY® Business Communications System and GuestWorks® Issue 6
Overview
555-231-208
Issue 1
April 2000
Glossary and Abbreviations
GL-34
time slot
64 kbps of digital information structured as 8 bits every 125 microseconds. In the switch, a time slot
refers to either a DS0 on a T1 or E1 facility or a 64 kbps unit on the TDM bus or fiber connection
between port networks.
TOD
Time of day
toll-free service
A service that allows incoming calls from certain areas to an assigned number a flat-rate charge
based on usage. The caller pays no toll fees.
tone ringer
A device with a speaker, used in telephones to alert the user.
TOP
Task-oriented protocol
trunk
A dedicated telecommunications channel between two communications systems or COs.
trunk-data module
A device that connects off-premises private-line trunk facilities and the system. The trunk-data
module converts between the RS-232C and the DCP.
trunk group
Telecommunications channels assigned as a group for certain functions that can be used
interchangeably between two communications systems or COs.
TSC
Technical Service Center
TTI
Terminal translation initialization
TTR
Touch-tone receiver
TTT
Terminating trunk transmission
TTTN
See tandem tie-trunk network (TTTN)
.
TTY
Teletypewriter
U
UAP
Usage-allocation plan
UCD
Uniform call distribution
UCL
Unrestricted call list