AT&T SYSTEM 25 Manual page 36

Direct Group Calling (DGC) allows incoming calls to be directed to a specific group of
terminals. Calls to a DGC group hunt in a circular manner, starting at the terminal following
the last one to receive ringing (whether answered or not), and will ring at the next idle
terminal in the group. DGC groups are particularly useful when the answering group
receives a high volume of calls. Call completion time is minimized and attendant assistance
is not required.
Up to 32 DGC groups, each including up to 20 members, may be set up. A terminal can be
in only one DGC group. Incoming calls on particular trunks can be directed to a DGC group.
These trunks can also be used for outgoing calls. Any number of outside trunks may be
administered to feed into a DGC group, but each trunk may feed only one DGC group.
If all group members are busy (off-hook), an outside call is queued and the caller receives
ringback tone. If the system includes a DGC delay announcement, it is played after a
specified number of rings. The caller is subsequently put on hold (in queue) and will receive
Music-on-Hold if available. If the system is not equipped with a DGC delay announcement,
the call will begin to ring at all Personal Line appearances of the trunk after the specified
interval.
The attendant can camp-on multiple outside (trunk) calls when all members of the group
are busy. Group members do not receive camp-on indication. The camped-on calls will be
queued, and are eligible for the DGC delay announcement. If no delay announcement is
available, the calls will return to the attendant console after a specified interval.
An inside caller dials a DGC access code to reach a DGC group. If all members of the group
are busy, the call will go into a queue if Callback Queuing is activated either automatically or
manually, otherwise, the call will not queue and the caller will receive busy tone.
a call begins to ring at a group member's station, it will not receive announcement
Once
service or ring at a line appearance. For this reason, it is important that DGC members
"log out" of the group when they will be away from their desks.
Internal stations can transfer outside (trunk) calls to a busy DGC group. The transferred call
will be treated as any other trunk call to a busy DGC group. The transferring party will hear
busy tone, but the transfer will complete. The call will queue and the calling party will
receive delay announcement, if available.
Direct Group Calling groups may be used for data applications to access host ports and the
STARLAN Interface CP. The System Administrator may disable queuing for data DGC
groups. Delay Announcements and Music-on-Hold are not provided for data DGC groups.
DGC groups can also be administered as Coverage Group receivers. See the entry for
"Coverage — Groups" on page 2-19 for additional information.
Direct Group Calling
Direct Group Calling 2-23