Ground-Start Lines/Trunks; Tie Trunks - AT&T MERLIN LEGEND Release 2.0 Equipment And Operations Manual

Lines and Trunks
Loop-Start Trunk Connection
The system's control unit can connect to another system's control unit from an
off-premises telephone (OPT) line to a loop-start line/trunk (or vice versa) via
analog facilities. A 008 OPT station module on system A's control unit can be
connected to a loop-start port on system B's control unit. This enables the user
on system B to access all the stations and facilities on system A. If System B
has remote access, the user on system A can directly access stations and
facilities on system B without operator intervention. Conversely, a loop-start port
on system A can be connected to an OPT port on system B.
NOTE:
If the systems are on the same premises, the connection can be made to
any T/R port.
With the OPT/loop-start connection, glare is more frequent as the volume of
calls increases. In addition, if system B (the loop-start interface) does not have
remote access, only the stations assigned to the loop-start facility on system B
can be accessed by system A.

Ground-Start Lines/Trunks

Ground-start lines/trunks are outside lines/trunks used by some businesses
(such as hotels or motels) where improved signaling is important. The improved
signaling of ground- start allows more secure toll restriction. In addition,
ground-start lines/trunks prevent glare. Ground-start lines/trunks also provide
cable losses ≤ 4.5 dB.
The following types of outside lines/trunks can be either ground-start or loop-
start:
Basic lines/trunks (used for both local and long- distance calls)
WATS (wide area telecommunications service)
800 service (in-WATS)
Foreign exchange (FX)

Tie Trunks

Tie trunks provide private communication between two systems. Tie trunks "tie"
the two systems together, making it seem that all the telephones are on the
same system. A tie trunk connection can be either analog or digital.
3-2 Tie Trunks