AT&T MERLIN LEGEND Release 3.1 System Manager's Manual page 59

Components
Table 2–1, Continued
Key Mode
Comments All users need multiline
phones.
Line assignments can
be customized by
phone or groups of
phones, for example,
you can assign tie
trunks only to the
telephones where
they're needed.
Components
The system consists of the following components:
Control Unit. The circuitry that manages the switching activities of the
telephone company's trunks and your system. It consists of carriers into
which modules (circuit packs) are inserted. The module types include a
processor module (the "brain" of the system), a power supply module,
and a variety of line/trunk or extension modules with jacks for connecting
the incoming trunks and the extension lines. The following section
explains line/trunk and extension modules in more detail.
A plastic cabinet (the cover) protects the control unit.
Telephones. Single-line, cordless, cordless/wireless, and analog
multiline telephones, as well as digital MLX telephones that offer a variety
of features and advanced capabilities. Most MLX telephones have
displays that show call information, list features for using the telephone,
and provide menu-driven programming instructions. MLX telephones
include the following: MLX-10, MLX-10D, MLX-10DP, MLX-16DP,
MLX-20L, and MLX-28D.
2–18
About the System
Hybrid/PBX Mode
Provides the most
efficient use of outside
trunks. The Automatic
Route Selection (ARS)
feature can be
programmed for the
cost-effective use of
pools and the greatest
protection against toll
fraud. Provides greater
functionality for single-
line phones than other
modes. Fewer line
buttons required for
users.
Behind Switch Mode
Users can have access to
most features of both the
local system and the host
system. Single-line
phones can be used.