AT&T MERLIN LEGEND Release 3.1 Maintenance And Troubleshooting Manual page 411

Glossary
personal line
PFT
pool
port
Power Failure
Transfer
power supply
module
PRI
primary system
operator position
GL–26
Maintenance and Troubleshooting
Central office trunk that terminates directly on one or more
telephones. In Hybrid/PBX mode , a personal line cannot
be part of a trunk pool . Also called "DFT" (direct facility
termination). Also refers to lines represented on line
buttons in Key Mode .
(Power Failure Transfer) Feature that provides continuity of
telephone service during a commercial power failure by
switching some of the system's trunk connections to
telephones connected to specially designated extension
jacks.
In Hybrid/PBX mode , a group of outside trunks that users
can access with a Pool button or by dialing an access
code on an SA button . Also used by the ARS feature when
choosing the least expensive route for a call.
See jack . Also, refers to extension or line jacks before
these are numbered according to the dial plan during
programming. The lowest jack on a module is always
Port 1.
See PFT .
Device that directs electricity to modules and telephones
on the system. One power supply module is needed for
each carrier, and an auxiliary power unit is added if the
module exceeds capacity.
(Primary Rate Interface) Standard interface that specifies
the protocol used between two or more communications
systems. As used in North America, provides twenty-three
64-kbps B-channel s for voice and/or data and one
64-kbps D-channel , which carries multiplexed signaling
information for the other 23 channels.
First jack on the first MLX or analog multiline extension
module in the control unit, that is, the extension jack with
the lowest logical ID in the system.