NEAX2400 IPX Feature Programming Manual
Page 280
NDA-24297, Issue 1
D-8
Direct Inward Dialing (DID)
D-8
Direct Inward Dialing (DID)
General Description
This feature provides for all incoming calls from the public network (except FX or WATS) to reach any system
station without Attendant assistance.
Operating Procedure
The calling party, outside the system, dials the telephone number as usual. However, the call is answered directly at
a predetermined station, bypassing the Attendant.
Service Conditions
1.
This feature requires that special DID trunks and telephone numbers be obtained through the local
telephone company.
Note:
Not all telephone company Central Offices are capable of providing this service.
2.
If the Central Office numbering plan differs from the user’s station numbering plan, addition or deletion
of digits can be implemented to coincide with the existing numbering plan.
3.
This feature is normally used when DIRECT-IN service is desired on an extensive or system-wide basis.
4.
DID is also frequently referred to as CENTREX service.
5.
If the called station is non-existent, the DID call is automatically routed to the Attendant or another
predesignated station. Calls to invalid numbers can be routed to an Attendant or to a recorded
announcement. See CALL FORWARDING - INTERCEPT/ANNOUNCEMENT
.
6.
Wink-start or delay-start signaling is recommended for use in conjunction with this feature.
7.
The DID trunk contains a switchable 2db transmission pad that is switched in or out via software control.
8.
If DID trunk is immediate start, dial pulse is required.
Interactions
1.
Incoming calls have priority over outgoing calls. When a register is assigned as an Outgoing Register
Trunk (ORT), it will also act as an Incoming Register Trunk (IRT) if no IRTs are available. Therefore,
ORTs can act as IRTs, but if IRTs are programmed, they will not act as ORTs.
2.
If immediate Start DID trunks are required, Incoming Register Trunks must be programmed in the same
local processor as the DID trunks.
3.
CALL FORWARDING [C-2, 3, 5]: When a station has activated a Call Forwarding feature (CALL
FORWARDING - ALL CALLS [C-5], CALL FORWARDING - BUSY LINE [C-2], CALL
FORWARDING - DON'T ANSWER [C-3]), the DID call is forwarded to a designated station rather than
to the specific station dialed.
4.
STATION HUNTING [S-7, 8, 9]: If the called station is arranged for this feature and is busy, the call
follows any prescribed hunting pattern.
5.
CALL WAITING - TERMINATING [C-12]: If the called station has the Call Waiting - Terminating
feature, Call Waiting ringback tone to the calling party is provided when the called station is busy. The
called station hears a 2-burst Call Waiting Tone. Call Waiting is allowed in CDN 46:CW, of ARDT
command.
6.
On an incoming call to a busy station, the Call Forwarding feature takes precedence over the Station
Hunting feature, and the Station Hunting feature takes precedence over the Call Waiting feature.
7.
The PA-8TLT circuit card provides interface capabilities for eight DID circuits.
