Specifications

Services and Features
August 08, 2000 68P81095E55-E C-1
Appendix C
Services and Features
Calling Features
Operational Controls
Item Description
North American
Dial Plan
The North American Dialing Plan is a 10-digit number format that
consists of three elements, The NPA element (Area Code), the
NXX element (prefix) and the XXXX element. It is often written
as NPA-NXX+XXXX.
• The NPA, defines a geographic area within a operating
company’s service area.
• The NXX defines a CO or MSO.
• The last four digits (XXXX) defines a specific user.
Within an Area Code only seven digits (NXX+XXXX) are needed
to complete the call. If the first digit in the sequence is not a 1, the
local Area Code is assumed.
Though not mandated by law conflicts are avoided by not
assigning the local NPA as an NXX to an exchange or service
within that NPA.
International Dialing Arrangements
The MSC and HLR support all dialing plans currently in use
throughout the world. A system routing table is used to translate
between the different dialing arrangements.
Maximum Outpulsing Digits on MF Trunk
The iDEN system supports both the ANSI Multi-Frequency and
ISUP outpulse standards to support international calling. For an
ANSI MF trunk the maximum outpulsed digits is 24. In ISUP and
ESTI MF trunks the maximum number is 15.
Alternate Routing Alternate Routing allows the system to sequentially scan multiple
trunk groups for an idle trunk to be used to complete the call.
Alternate routing allows dialed digits to be modified to comply
with the requirements imposed by the point-of-penetration into the
PSTN networks. When no idle trunk is found, the system
terminates the call as determined by the MSCs Call Treatment.
Roaming
Restrictions
Roaming restrictions enable the service provider to impose
roaming constraints. Three classes of roaming restrictions can be
implemented.
• No restrictions
— permits roaming to all linked iDEN
®
networks.
• National roaming
— prevents the subscriber from roaming
outside the home PLMN country.
• Local roaming
— prevents the subscriber from roaming
outside the home PLMN.
All these functions assume that unique PLMNs exist.