Ericsson iPECS-100, Feature Description And Operation Manual

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iPECS-LIK
Feature Description & Operation Manual
Issue 6.1
285
4.9 DIRECT INWARD DIAL (DID)
Description
A carrier service, known as Direct Inward Dial (DID), sends digits to the system so that the call
may be routed directly to a specific station or system facility. Digits sent to the system are
generally the last digits (3 or 4) dialed by the caller. DID service is available over analogue,
digital, and packet networks. Analogue DID lines are limited to one-way incoming service and
require special call-start signaling definition. ISDN lines can provide two-way, incoming DID and
normal outgoing service, and require no special signaling.
After collecting the digits from the carrier, iPECS converts the digits employing one of three DID
digit conversion Types:

Type 0 - collect incoming digits based on the programmed digit count and convert the
digits according to the DID conversion pattern, resulting in the DID destination
number.

Type 1 - use the incoming DID digits as the destination number without converting.

Type 2 - Following the result of DID conversion Type 0, route the call according to
the Flexible DID table conversion.
Operation
System
System response to an incoming DID call (analogue CO line):
1. set-up a connection based on the defined Start signal,
2. collect incoming digits based on the programmed Receive Digit Count,
3. handle digits based on the Conversion type (0-2),
4. route the call to assigned destination.
System response to an incoming DID call (ISDN line):
1. set-up a connection based on the received call set-up messages,
2. collect incoming digits and delete digits from left based on the programmed ISDN
Remove Digit Count,
3. handle digits based on the Conversion type (0-2),
4. route the call to assigned destination.
Conditions
1. If ICLID routing is assigned for the CO/IP Line, the received Caller Id is compared to
the ICLID Table for routing first. If Caller Id does not match an entry in the ICLID
Table, the normal DID call processes are used.
2. DID calls that encounter a busy signal, are not answered in the DID/DISA No
Answer Timer, or are received at a vacant or invalid number can be routed to the
Attendant, a tone, Station group, or VMIM/VSF announcement. When the
Attendant receives such calls, the call is appropriately identified by the Attendant
iPECS Phone display.
3. For a station that is part of a non-pilot Station Hunt group, DID calls will follow the
group hunt process if the Station is busy or does not answer the call.