AT&T MERLIN LEGEND System Reference Manual page 155

Features
Call Waiting and
Camp-On
Coverage
Directory
Disallowed Lists
Do Not Disturb
Extension Status
Forward and Follow Me
Group Calling
2-106 Direct-Line Console
When the DLC system operator uses Camp-On to transfer a call to a busy
extension, the call is placed in the Call Waiting queue and the caller hears the
Call Waiting tone whether or not the extension has the Call Waiting feature
activated.
If the system is programmed for One-Touch Transfer with automatic completion,
the system operator uses Camp-On by pressing the Transfer button, dialing the
extension manually, activating Camp-On, hanging up, and pressing another line
button or the Transfer button again. If the system operator presses an Auto Dial
or DSS button, the transfer is automatically completed and Camp-On cannot be
used.
A DLC can be both an individual or Group Coverage receiver and a member of
a coverage group. No more than eight Primary Cover, Secondary Cover, or
Group Cover buttons can be assigned on a DLC.
A system operator with a digital DLC can use all the Directory features.
Disallowed Lists can be assigned to DLCs. Since restrictions imposed by a
Disallowed List assignment apply to the telephone used to initiate a call transfer
to an outside number, a user with a restricted telephone can circumvent
restrictions by asking a system operator with an unrestricted console to connect
an outside call.
The green LED next to an Auto Dial or DSS button on a DLC goes on when a
user activates Do Not Disturb.
Extension Status capability can be assigned to DLCs only. In the hotel
configuration, only a DLC system operator can change an extension to status 0.
In the Group Calling/CMS configuration, a calling group or CMS supervisor uses
a DLC to monitor and change group member status.
A DLC system operator can forward calls to extensions and, if the capability is
assigned in system programming, to outside telephone numbers. Since outside
lines are assigned as Personal Line buttons on the console, the capability to
forward calls received on each outside line (excluding loop-start lines/trunks
with unreliable disconnect) to an outside number must also be assigned in
system programming and can be assigned to only one telephone for each
individual line/trunk.
A DLC can be a member of a calling group and is normally used as the calling
group supervisor position.