MERLIN LEGEND Communications System Release 6.0
System Programming
555-660-111 Issue 1
February 1998
Glossary
PageGL-22
power supply
module 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 needed.
PRI (Primary Rate Interface) Standard interface that specifies
the protocol used between two or more communications
systems. As used in North America, it provides twenty-
three 64-kbps
B-channels
for voice and/or data and one 16-
kbps
D-channel
, which carries multiplexed signaling
information for the other 23 channels.
primary system
operator position 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.
prime line Individual extension number assigned to a telephone in a
system operating in
Behind Switch mode
. Each telephone
user has his or her own prime line and is automatically
connected to that line when he or she lifts the handset.
private
communications
network or private
network
An interconnected group of
communications systems
,
which may consist of MERLIN LEGEND Communications
Systems, DEFINITY Enterprise Communications Servers
(ECS), and/or DEFINITY ProLogix Solutions.
private network
trunks The facilities that connect
communications systems
in a
private network
. See also
tandem tie trunks
and
tandem
PRI trunks
.
processor module Module in the second slot of the control unit
(Slot 0, to the
right of the
power supply module
). Includes the software
and memory that runs the system.
programming port
reassignment Reassignment of the system programming jack position to
any of the first five extension jacks on the first MLX module
in the control unit.
protocol Set of conventions governing the format and timing of
message exchanges between devices, such as an MLX
telephone and the control unit.
PSTN Network that is commonly accessible for local or long-
distance calling. Also called “public network” or “public
switched network.”
PSTN trunk In a
private network
, a facility that connects a networked
system to the public switched telephone network.
public switched
telephone network See
PSTN.