Lucent Technologies 6.1 manual Assigning Lines/Trunks to Data Video Stations, SecurityAlert

MERLIN LEGENDCommunications System Release 6.1			Issue 1
System Planning 555-661-112			August 1998
5 Data Communications
	Assigning Lines/Trunks to Data and Video Stations		Page 5-27
	Assigning Lines/Trunks to Data and	5
	Video Stations

The following types of outside lines/trunks are used to make and receive data 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:

—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.

—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.

■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.

The following kinds of outside ground-start or loop-start lines/trunks can be used 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:

—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