Lucent Technologies 6.1 用户手册
MERLIN LEGENDCommunications System Release 6.1
System Planning
System Planning
555-661-112
Issue 1
August 1998
Data Communications
Page 5-27
Assigning Lines/Trunks to Data and Video Stations
5
Assigning Lines/Trunks to Data and
Video Stations
Video Stations
5
The following types of outside lines/trunks are used to make and receive data
calls to and from data stations outside of the system:
calls to and from data stations outside of the system:
■
Loop-Start (LS). This is the standard line/trunk for homes and small
businesses, and can be used to communicate with outside modem data
stations. Video calls are not made over loop-start lines/trunks. Loop-start
lines/trunks are the least expensive lines/trunks in some areas but have the
following disadvantages:
businesses, and can be used to communicate with outside modem data
stations. Video calls are not made over loop-start lines/trunks. Loop-start
lines/trunks are the least expensive lines/trunks in some areas but have the
following disadvantages:
— They do not protect against glare, a condition that occurs when an
outside call is made at the same time that an incoming call arrives
on the same line/trunk.
on the same line/trunk.
— They may not provide reliable far-end disconnect for toll restriction.
!
SecurityAlert:
Toll fraud can occur when loop-start lines/trunks are used with unreliable
disconnect. If the calling party stays on the line after the called party hangs
up, the central office returns a dial tone at the conclusion of the call enabling
the caller to place another call as if it were being placed from your company.
disconnect. If the calling party stays on the line after the called party hangs
up, the central office returns a dial tone at the conclusion of the call enabling
the caller to place another call as if it were being placed from your company.
■
Ground-Start (GS). This line/trunk is preferred for communication with
outside modem data stations. Ground-start lines/trunks provide improved
signaling and reliable far-end disconnect for secure toll restriction. Video
calls are not made over ground-start lines/trunks.
outside modem data stations. Ground-start lines/trunks provide improved
signaling and reliable far-end disconnect for secure toll restriction. Video
calls are not made over ground-start lines/trunks.
The following kinds of outside ground-start or loop-start lines/trunks can be used
for data communications:
for data communications:
— Basic lines/trunks
— Wide area telecommunications service (WATS)
— 800 service (inbound WATS)
— Foreign exchange (FX)
Ground-start/loop-start lines/trunks connect to ground-start/loop-start jacks on the
following types of modules in the control unit:
following types of modules in the control unit:
— 800 GS/LS
— 400 GS/LS/TTR
— 408 (LS lines/trunks only)
— 408 GS/LS
— 400 (LS lines/trunks only)
— 800 (LS lines/trunks only)
— 408 GS/LS-MLX
— 800 GS/LS-ID