Modes Of Operation - AT&T MERLIN LEGEND Release 2.0 Equipment And Operations Manual

Introduction
Each module has a DSE to interface codecs or digital transceivers to the TDM
bus. The actual digital switching occurs when the DSE is programmed by the
system I/O bus to transmit data on or receive data from the TDM bus in specific
time slots. In addition, the DSE can sum digital signals from designated TDM
slots to provide conferencing for up to five parties.

Modes of Operation

NOTE:
Although the terms "line" and "trunk" technically refer to different facilities,
the differentiation is not as clear as it once was, and the terms are usually
treated as if they are interchangeable. A "line" traditionally connects a
piece of equipment to a switching system; for example, it connects your
home telephone to the local telephone company. A "trunk" connects one
switching system to another switching system; for example, it connects a
communications system like this (except for facilities line personal lines that
pass transparently through the system) to the local telephone company's
central office (CO). Since the industry trend seems to be toward using
"trunk" to refer to either facility, this standard is used in this section.
The system can be programmed to operate in Key, Hybrid/PBX, or Behind
Switch mode. The mode of operation determines the following:
The types of outside trunks that can be connected to the system
How telephone users access outside trunks
The types of system operator consoles allowed
The features available and how they work
The following sections describe each mode of operation, and Table 1-1
summarizes the modes.
Table Modes of Operation Summary
1-1.
Trunks connected directly to
control unit:
Ground-start
KF registration (FCC)
MF registration (FCC)
PF registration (FCC)
Loop-start
PRI
DSI
1-12 Modes of Operation
Hybrid/PBX
Key
No
No
Yes
Yes
No Yes
Yes Yes
Yes Yes
Yes
Yes
Continued on next page
Behind Switch
No
Yes
No
Yes
Yes
Yes