Panasonic FP-D250 User Manual page 622

Twisted Pair Two insulated copper wires twisted together with the twists or lays
varied in length to reduce potential signal interference between the pairs. Where
cables comprise more than 25 pairs, they are usually bundled and wrapped in a
cable sheath. Twisted pair is the most common medium for connecting phones,
computers and terminals to PABXS. With the IEEE ratification of 10BaseT for
networking 10Mbit/s Ethernet over UTP telephony wiring, twisted pair has become
ubiquitous. As well as performance at Ethernet rates, it offers cost benefits to the
end user through flexibility - ease of relocation. New data-grade and even voice-
grade UTP methods support l00Mbit/s transmission, with 155Mbit/s ATM a probability.
Type A Intelligent Network term describing IN services evoked by, and affecting, a
single user. Most of them can only be invoked during call setup or teardown.
Type B Intelligent Network term describing IN services invoked at any point by, and
affecting directly, several users.
U
UNIX An operating system for a wide variety of computers from mainframes to PCs.
Supports multitasking transactions and is suited to multi-user environments. Best
suited to network computing. Its command syntax is very hard to learn, so its usually
used by advanced computer users. A large number of UNIX computers have been
installed at colleges, universities and military installations in the U.S. There used to
be numerous incompatible versions of UNIX operating systems developed by many
different organizations, but since the release of system 5 in 1983, most UNIX systems
are more or less compatible with each other. Some recently released Oses have
been developed based on or using some components of the UNIX OS. Numerous
Internet sites are developed with UNIX servers and workstations.
UPS (Uninterruptible Power Supply) A battery, attached to a piece of hardware, for
example a server, that provides backup power for conducting an orderly shutdown if
the server's normal power supply fails.
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