Instruction manual

Incoming Trunks
T1 Data Operation. Available in Release 4.0 and later, T1 data
operation allows high-speed data communications over the public
switched network; this is called
T1 Switched 56 service . It also
provides data tie “
lines
” to connect one MERLIN LEGEND
Communications System to another or to a DEFINITY

system. A
T1 data-operation “
line
” is a B-channel.
Primary Rate Interface (PRI) Operation. The 24 “
lines
” include 23
B-channels. Each B-channel can dynamically provide voice and
data services; one D-channel carries signaling information for the
B-channels.
NOTE:
Facility is a general term that designates a communications path between a
telephone system and the telephone company central office. Technically, a
trunk connects a switch to a switch, for example, the MERLIN LEGEND
Communications System to the central office. Technically, a
line is a loop-start
facility or a communications path that does not connect switches, for example,
an intercom line or a Centrex line. However, in actual usage, the terms
line and
trunk are often applied interchangeably. In this guide, we use lines/trunks and
line/trunk to refer to facilities in general. Specifically, we refer to digital facilities .
We also use specific terms such as
personal line , ground-start trunk , DID trunk ,
and so on. When you talk to your local telephone company central office, ask
them what terms they use for the specific facilities they connect to your system.
2–14 About the System