Lucent Technologies MERLIN LEGEND 6 - Manual (Page 451)

MERLIN LEGEND Communications System Release 6.0
System Manager’s Guide
555-660-118
Issue 1
February 1998
Glossary
Page GL-27
V
unambiguous
numbering The practice of numbering of extension ranges, remote
access codes, or other system components to avoid routing
conflicts in network or local calling. For example, Extension
441 is unique when compared to Extension 4410. However
it is ambiguous, because a system routes as soon as it
matches the digits sent for a call with the digits in a local
plan or in a non-local dial plan extension range. When a
caller dials
##  , a system routes the call to Extension 441
immediately, without considering the last dialed digit.
Uniform Dial Plan See UDP.
uninterruptible
power supply See UPS.
unit load Measure of the power load drain of a module, telephone, or
adjunct.
unmonitored
extension An extension for which no CTI application is receiving call
information. See also
CTI link and monitored extension.
unrestricted data
channel Unrestricted data channels (also called clear data
channels) allow the transmission of occurrences of more
than seven contiguous zero bits. If an unrestricted data
channel is requested and only restricted channels are
available, the call will be rejected. See also restricted data
channel.
UPS (uninterruptible power supply) Device that connects to the
system to provide 117 VAC to the equipment when the
commercial power source fails.
VAC (alternating-current voltage)
VDC (direct-current voltage)
VMI (voice messaging interface) An enhanced tip/ring port.
videoconferencing
system System application that allows face-to-face meetings, with
voice and video, to occur between individuals or groups.
This application requires high-speed data transmission
facilities. See also
desktop videoconferencing and group
videoconferencing.
virtual private
network See VPN.
VPN (virtual private network) A type of private network that uses
the switching capabilities of the PSTN, rather than tandem
switching, to direct calls between connected
communications systems. A VPN may constitute a part of a
private network.
voice-band
channel A transmission channel, generally in the 300–3400-Hz
frequency band.