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Introduction to Local Number Portability

Version 2.0
April 2003

Table of Contents

	Section 1 Local Number Portability Overview
	Section 2 Terminology

This document provides an overview of Local Number Portability (LNP) and defines terms used in LNP.

1 Local Number Portability Overview

What exactly is Local Number Portability? Local Number Portability (LNP) is:

"the ability of users of telecommunications services, to retain, at the same location, existing telephone numbers without impairment of quality, reliability, or convenience when switching from one telecommunications carrier to another."

So, what does that mean? It means that anyone can change from one telephone service provider to another without having to change their telephone number.

In 1995 the telecommunications industry began to seriously investigate ways of providing Local Number Portability. LNP would open the door for competition within the local telephone service market place, something not technically feasible prior to this. During 1995 and 1996 several state regulatory bodies, notably the Illinois Commerce Commission (ICC) began the process of officially selecting the architecture to be used for Local Number Portability in their respective states. After considerable discussion and deliberation, AT&T/Lucent Technologies' Location Routing Number (LRN) architecture was selected by the ICC, and other participating state regulatory bodies. The LRN method became the de facto industry standard and was later adopted by the Federal Communications Commission in 1997. On February 8, 1996, President Clinton signed The Telecommunications Act of 1996 into law. It was the first major overhaul of telecommunications law in almost 62 years. It provided a pro-competitive, de-regulatory national policy framework designed to open local telecommunications markets to competition.

The FCC issued its First Report and Order adopted June 27, 1996 and released July 2, 1996 in Docket 95-116 regarding telephone number portability and provides the regulatory framework for making LNP a reality. The FCC First Report and Order specified proposed rules for the establishment of regional local number portability databases to implement LNP and specified the need for a neutral, third party administrator.

In February of the same year, under the supervision of the ICC and carriers participating in an ICC-workshop, an RFP was released inviting prospective vendors to submit a total solution and associated firm pricing proposal to provide a Number Portability Administration Center and Service Management System (NPAC SMS) to support the implementation of Number Portability in one Chicago, Illinois, LATA. It defined the LNP architecture to be used, the functions of the Service Management System and the management and integration functions of the Number Portability Administration Center (NPAC).

Two functional interfaces into the Service Management System were defined for Service Providers: (1) Service Order Activation (SOA); and, (2) Local Service Management System (LSMS). The SOA is used to communicate information to the NPAC SMS and back to the Service Provider. The LSMS is the Service Providers' database containing all information required for correct call routing when a customer changes from one service provider to another.

Also, the Low Technology Interface (LTI) was defined. The LTI is the graphical user interface (GUI) used for communication between the SOA, LSMS, and the NPAC SMS.

In August 1997, eight regional LNP databases were established coinciding with the seven original Bell Operating Company (BOC) regions, and Canada making the eighth. Limited Liability Corporations (LLC) were formed in each of these regions to select the NPAC SMS vendor and service for their region. Lockheed-Martin Information Management Services ultimately became the vendor of choice for all eight LLCs. In November 1999, Lockheed-Martin Information Management Services became NeuStar, Inc. NeuStar continues to be the LNP Administrator managing the NPAC.

The Canadian Radio and Television Commission (CRTC) also adopted a regulatory framework for implementation of LNP throughout Canada.

NeuStar, Inc., a neutral, third party administrator was awarded the contract for the NPAC SMS and provides a total solution for maintaining, administering, and operating the regional number portability administration center and service management system for the implementation of LNP. The NPAC SMS is the system that manages the porting of telephone numbers from one LSP to another. NeuStar, Inc. has developed the Number Portability Administration Center (NPAC) to support the implementation of Local Number Portability (LNP).

2 Terminology

AIN	Advanced Intelligent Network Evolving service-independent network architecture that provides important new capabilities for rapid creation of customized telecommunications services. AIN offers one way for a network element to query a central database to obtain local number portability information.
BGP v4	Border Gateway Protocol A protocol that enables groups of routers (called autonomous systems) to share routing information so that efficient, loop-free routes can be established. The primary function of a BGP-speaking system is to exchange network reachability information with other BGP systems. BGP v4 is defined in RFC 1771.
BOC	Bell Operating Company (also known as RBOC) There are regional Bell companies spun off from AT&T at the time of divestiture. Today the BOCs, together with independent telephone companies, are the primary providers of local telephone service.
CLEC	Competitive Local Exchange Carrier Considered to be a new entrant into a market where there is already an incumbent LEC providing local phone service.
CLASS	Custom Local Area Signaling Services Premium local service features, such as call forwarding or automatic callback
CNAM	Caller ID with name.
DIPS	Refers to database dips. A query by a local switching office or toll switching office to a remote database.
DPC	Destination Point Code The part of a routing label that identifies where the CCS/SS7 signaling message should be sent.
FCC	Federal Communications Commission U.S. Congressional government entity endowed with the responsibility to direct the U.S. national telecommunications regulatory environment.
FOC	Firm Order Confirmation Verification/acknowledgment from one SP to another of receipt of a valid Service Request (SR).
FRS	Functional Requirements Specifications for the NPAC SMS
GTT	Global Title Translations
IIS	Inter-Operability Interface Specifications for the NPAC SMS
ILEC	Incumbent Local Exchange Carrier Typically, the RBOC or independent who services all local end-users (prior to a market opening up to local competition).
IN	Intelligent Network Hardware and software platform used to provide enhanced voice, video and data services. IN offers one way for a network element to query a central database to obtain local number portability routing information.
INC	Industry Numbering Committee An industry group of service providers, vendors and other interested parties who focus on public network numbering plan issues.
ISVM	Inter-Switch Voice Mail
IXC	Inter-Exchange Carrier A carrier that provides connections between LATAs, between service areas, and between LATAs and serving areas where the calling or called end-user is located in the U.S.
LAN	Local Area Network A group of client computers connected to a server.
LATA	Local Access Transport Area Geographic region within which a local telephone company can offer regional toll and access services. Transportation of information beyond the LATA must be accomplished by an IXC.
LEC	Local Exchange Carrier The company, most often a local Bell Operating Company, that provides local telephone service. LECs also include independent local telephone companies.
LIDB	Line Identification (Information) Database
LLC	Limited Liability Corporation The jointly-owned legal entity which is responsible for oversight and administration of the regional NPAC. While all certified LSPs can use the NPAC, only official members have a vote in its business decisions.
LNP	Local Number Portability The ability to port TNs without changing telephone numbers.
LRN	Location Routing Number A 10 digit number used to uniquely identify a switch that has ported numbers. LRN utilizes AIN triggers, SS7 signaling, and unique 10 digit code for switch identification.
LSMS	Local Service Management System The LSP owned network database which holds downloaded ported number information.
LSP	Local Service Provider A company that provides basic local telephone service
MSA	Metropolitan Statistical Area The coverage area of a city as in a telephone network. A U.S. Census Bureau term.
N-1	N minus 1 The next to last network involved in a particular call. In the case of an inter-LATA call, for example, the next to last network is the inter-exchange carrier network.
NANC	North American Numbering Council FCC-mandated task force assigned to oversee NPAC and NANP administration for the US telecommunications industry.
NANP	North American Numbering Plan A plan for the allocation of unique 10 digit telephone address number.
NPAC SMS	Number Portability Administration Center Service Management System The system used by the NPAC to manage number portability processes and information.
NSP	New Service Provider Subscribers selection of exchange carrier that will be providing dial tone. This will usually be the exchange carrier that is not the default SP for the NPA. This would be the recipient switch for the porting of a number when the end-user is being ported. When the end-user is changing from ported to non-ported the NSP would be the donor switch.
NXX	End office Code A three digit code used to identify a central office exchange. However, in a portable environment the last 4 digits or the 7-digit telephone number may not always reside in the central office exchange to which the NXX was natively assigned.
OSPF	Open Shortest Path First A popular routing discovery protocol, designed by the OSPF working group of the Internet Engineering Task Force. It is an Interior Gateway Protocol.
OSS	Operations Support System
QUC	Query on Request
RFP	Request for Proposal
SCP	Service Control Point Transaction processor-based system that provides network interface to database services.
SMS	Service Management System Computer facility permitting access to records contained in the number portability database.
SOA	Service Order Administration Interfaces to the NPAC SMS for provisioning ported end-user data.
SP	Service Provider A company that provides telephone service.
SSP	Service Switching Point or service switch point A switching office that has the SSP features, enabling interactions with SCPs action with SCPs.
SS7	Signaling System 7 an internationally standardized, general-purpose CCS protocol. It defines the signaling backbone for the public switched telephone network.
STP	Signal Transfer Point A Signaling point with the function of transferring signaling messages from one signaling link to another and considered exclusively from the viewpoint of the transfer. A packet switch that transmits messages between switches and other network components. Also transmits messages between switches in the process of normal call set-up and routing
SV	Subscription Version
TCAP	Transaction Capabilities Application Part TCAP is the application layer of the Transaction Capabilities protocol that is used for messages between end offices and remote databases.
TCP/IP	Transmission Control Protocol and Internet Protocol Internet protocol suite developed by the U.S. Department of Defense in the 1970's. TCP governs the exchange of the sequential data. IP routes outgoing and recognized incoming messages.
WAN	Wire Area Network
WWW	World Wide Web