N

NANC - North American Numbering Council
    A 34-member industry council appointed by the FCC, which must choose an independent
numbering administrator to assume from Bellcore the responsibility of administering the North American Numbering Plan (NANP).

NANP - North American Numbering Plan
    Assigns area codes and sets rules for calls to be routed across North America.  A plan for
the allocation of unique 10 digit address numbers.  The numbers consist of a 3 digit area code, a 3 digit office code and a 4 digit line number.

Narrowband
     A low-capacity communications circuit / path used for only voice, facsimile images, slow-scan
video images and data  transmissions at kilobit speeds.  It usually implies a speed of 56 Kbps or less.

NASC - 800 Number Administration and Service Center
    The organization that administers the SMS/800 system for the reservation, registration and
administration of all North  American 800 numbers for all carriers. (See 800 Portability,       RespOrg and SMS/800)

NC Codes - Network Channel Codes
     Industry standard codes that define the type of service being provided at each end of a circuit.

NCI Codes - Network Channel Interface Codes
    Industry standard codes that define the wiring, protocol, signaling, etc which are to be used as an interface on the A Location of a circuit.

NE - Network Element
    A system that supports at least NEFs and may also support Operation System Functions/Mediation Functions.  An ATM NE may be realized as either a stand alone device or a geographically distributed system.

NEF - Network Element Function
    A function within an ATM entity that supports the STM based network transport services.

NENA - National Emergency Number Association
    National industry forum that includes police, fire, community administrators and telecommunications vendors (service providers) with a involvement in emergence 911 services.

NETBIOS - Network Basic Input/Output System
     This system provides a Session layer interface between network applications running on a PC and the underlying protocol  software of the Transport and Network layers on the ODI model.  Normally a LAN protocol.

Network
     A system of interrelated elements that are interconnected in a dedicated or switched linkage
to provide local or remote  communication (of voice, video, data, etc.) and to facilitate the exchange of information between end users with common  interests. The set of switches, circuits, trunks and software that make up a telecommunications facility.

Network Control Center - NCC
     Equipment, people, systems and procedures that monitor network activity and react to unusual situations.  Also known as  Network Operations Center (NOC) which performs the testing, installation and maintenance functions with regard to  individual circuits.
 
Network File System - NFS
     This system is a protocol developed to use IP and allow a set of computers to access each
other's file systems as if they  were on the local host.

Network Node Interface - NNI
    An ATM term which describes the interface between two public network pieces of equipment.
A protocol defined by the ATM forum to govern how ATM switches establish connection and how
ATM requests are routed through the network.

Network to Network Interface - NNI
    A connection between two public frame relay services, and includes elements such as bi-directional polling, to assist the network services providers with gaining information on the status of the public networks being interconnected.

Network Service Address
    Unique addresses that define physical or logical locations in equipment, such as a residential
telephone number.

Node
     Generic term used to refer to an entity that accesses a network.

Noise
    Unwanted electrical signals introduced into telephone lines by circuit components or natural
disturbances which tend to degrade the performance of the line.

Non-Blocking
    A PBX is non-blocking if all callers can be switched through the PBX even during the busiest
time of day.  Indicates that the internal network of the switching system is such that the total
number of available transmission paths is equal to the number of ports.

Non-Recurring Charge - NRC
     Also known as OTC - One-Time (Setup) Charge.

NPA - Numbering Plan Areas
     North American "Area Codes." (3 digits: 2-to-9, 0-or-1, 0-to-9. Middle digit to expand soon)

NPAC - Number Portability Administration Center
    The regional, neutral third-party center which administers number portability transactions between
    service providers, handles conflict resolution and assists carriers in synchronizing the porting processes.

NPA Routing
     Area Code Routing. Route calls based on the originating ANI NPA (area code.)

NPA Split
     Subdividing an area code, with the creation of a new area code. This is necessary when the
number of telephones in an area  code (NPA) grows to an excessive number.

NSP - New Service Provider
    Subscribers selection of exchange carrier that will be provided dial tone.  This will usually be the exchange carrier that is not the default SP for the NPA.  This is also the recipient switch for the porting of a number when the end-user is being ported.

Number Portability
    The ability for telephone subscribers to take their phone numbers with them when they change
telephone service providers.
 
NXX
     Exchanges (First 3 digits of a 7-digit phone number). (2-to-9, 0-to-9, 0-to-9) (Digits 4, 5 and 6 in a 10 digit NANP telephone  number - NPA-NXX-XXXX).   Identifies the specific telephone company central office which serves that number.