MERLIN LEGEND Communications System Release 5.0
Feature Reference
555-650-110
Issue 1
June 1997
Features
Page 461
Primary Rate Interface (PRI) and T1
Incoming Calls
3
1
In Release 1.0 and 1.1 systems, incoming calls are routed by line appearance.
Beginning with Release 2.0, incoming calls also can apply routing by dial plan, a
routing system for incoming calls programmed by the Dial-Plan Routing Table
(see
Routing by Dial Plan (Hybrid/PBX Only).
Routing by dial plan is similar in
concept to Direct Inward Dial (DID). It provides the ability to direct a call
automatically to the proper destination for improved call distribution and call
handling. Unlike a DID line, a PRI line (or T1 line in Release 4.0 or later)
programmed for routing by dial plan can accommodate outgoing calls as well as
incoming calls. As with DID operation, this feature is available only in Hybrid/PBX
mode.
PRI Routing by Dial Plan.
Routing by dial plan also allows multiple calls to a
directory number. Concurrent incoming calls with the same Called Party Number
can be delivered to a destination simultaneously.
The Dialed Number Identification Service (DNIS) is a service attribute of the
Megacom 800 service. Based upon customer-selected parameters, such as area
code, state, or time of call, it provides distinct Called Party Numbers for incoming
800 and 900 calls. In Release 1.0 and 1.1 systems, DNIS has the restriction of
one active call per Called Party Number for each B-channel group. The PRI
telephone number, which is matched against the Called Party Number(CdPN), is
used for routing a call to a specific line that normally terminates on a personal line
button. In Release 2.0 and later systems, the restriction of one active call for each
CdPN does not apply.
For each B-channel group, the system can be programmed for either routing by
line appearance or routing by dial plan. With routing by dial plan, the Dial-Plan
Routing Table must be programmed to contain a series of patterns—the number
of digits in the Called Party Number (CdPN), network services on which to match,
and a number of digits to add or delete for each match—in order to route the call
to the proper destination.
If a B-channel group is programmed for routing by dial plan, all calls into that
B-channel group are routed in a DID-like manner and terminate on an SA button,
on a single-line telephone, into a calling group queue, or at a Queued Call
Console (QCC). When an incoming call arrives, its network service type and
Called Party Number are compared to entries in the Dial-Plan Routing Table. If no
match is found, the call is routed to the programmed backup position for
unassigned DID calls (normally the primary system operator). If a match is found,
the Called Party Number is manipulated according to the Dial-Plan Routing Table
before matching it against the inside dial plan to identify a destination to which the
call is delivered. If the manipulated Called Party Number does not match an inside
extension, it is treated as an unassigned DID call.
If a fast busy tone is programmed as the routing destination for unassigned Direct
Inward Dial calls, the call is rejected. This typically causes the network to return an
intercept tone instead of a fast busy tone. If the number matches a destination
