Time-Of-Day Routing - Nortel DMS-250 Reference Manual

restricted class 3
If the authcode associated with a call type is time-restricted, the date and
time of the origination are compared against the restricted times for the
subscriber. The origination date and time are calculated by using the local
time bias field in the originating trunk group (field TIMEBIAS). This field
specifies whether to add or subtract up to 12 hours in one-hour increments
from the DMS-250 switch time to calculate the call origination date and
time.
Calls failing restricted usage by date and time screening are blocked and
given restricted usage treatment. Depending on service subscription
parameters, cause-to-treatment mapping may be performed.
Incoming exclusion
Incoming exclusion prevents subscribers from calling back into their own
local calling area. In this way, intrastate traffic that is not permitted for
specialized common carriers by individual state public utilities commissions
can be blocked. Incoming exclusion is performed only on offnet numbers of
at least six digits. If the offnet number consists of exactly seven digits, the
trunk group parameter SNPA is temporarily prefixed onto the dialed digits
before screening is performed. This ensures that screening is performed
against the intended NPA-NXX combination.
The trunk group parameter IEXCLINX controls incoming exclusion.
IEXCLINX specifies which of the 160 area codes are excluded. Up to eight
of these excluded area codes can be further excluded down to the exchange
code (NXX) level. Up to 256 incoming exclusion schemes may be specified.
If a DDD number is collected from the dialed digit stream or retrieved from
a speed list, the first three or six digits of the ten-digit number are compared
against the excluded NPA and/or NPA-NXX combinations for that
originating PRI interface. Calls that are excluded are given local call area
barred treatment; this may result in treatment-to-cause mapping.

Time-of-day routing

Time-of-day routing allows or denies route choices based on the time of day.
Routes can also be varied based on the day of the week or the day of the
year (to account for weekends and holidays). This provides a cost-effective
use of facilities.
Time-of-day routing for the DMS-250 switch is done for the routing tables
as a refinement of the conditional selectors (CND, NOT). This allows
efficient routing to other routes in and between these tables as a function of
time of day. Because time-of-day routing uses the existing capabilities of the
Digital Switching Systems DMS-250 ISDN Reference Manual MWC14 (CSP14)
Feature interaction 7-19