Ramneek Dhingra

08EL280

NUMBER

PORTABILITY

AbstractNumber Portability is a telecommunications

network feature that enables end users to retain their

telephone numbers when changing service providers,

service types, and/or locations.

In this paper we have analyzed Number

Portability , its types and, the wireline LNP

architecture and its process. We have analyzed the

benefits of using Number Portability.

We conclude that it brings challenges and

opportunities for old and new telecommunications

providers and choice to the end-users without the

inconvenience of changing their numbers.

Introduction

Number Portability is a telecommunications network featurethat enables end users to retain their telephone numbers whenchanging service providers, service types, and/or locations.

The Telecommunications Act of 1996 (TA 96) tore downmost of the significant barriers to unfettered competition intelecommunications. However, the inability of end users toretain their telephone numbers when changing serviceproviders caused great inconvience to them.

With the help of congress and FCC it enabledconsumers and businesses to choose new providers, services,and locales while retaining their phone numbers, therebyfostering competition in the telecommunications industry.

Number Portability

TYPESThere are basically three types of number portability:

• Service operator Portability

• Location Portability

• Service Portability

Service Operator Portability

• Historically, all directory numbers in one Numbering

Plan Area-Central Office Code (NPA-NXX) were

assigned to a single telephone switch.

• A customer who wanted to change local service

providers faced the potential costs and

inconveniences of changing to a new phone number.

• With the Telecommunications Act of 1996, FCC

mandated that all numbers be portable to all local

exchange competitors

• The Act defined service number portability as the

ability of end users to retain existing directory

numbers (DN) at the same location as they change

from one service provider to another.

• With the introduction of local number portability,

individual directory numbers in one NPA-NXX were

moved to a different telephone switch

• the concept of a location routing number (LRN) was

introduced

• Each switch that hosts portable numbers was assigned a

10-digit LRN that was used in routing a call to that

switch.

• All LNP-capable network elements, including service

switching points (SSPs), signal transfer points (STPs),

and signal control points (SCPs), must maintain a list of

NPA-NXXs that are considered portable.

Location Portability

• It is the ability of users to retain existing directory

numbers without impairment of quality, reliability, or

convenience when moving from one physical

location to another

• In this case, a given telephone number could be

associated with any network termination device,

independent of location.

• Acc to FCC nothing in the Act would preclude it

from mandating location portability in the future;

however, no requirements have yet been designated

or mandated.

Service portability

• It is the ability of users to retain existing directory

numbers without impairment of quality, reliability, or

convenience when switching from one service to

another service provided by the same carrier.

• The FCC has not addressed service portability at this

time, and requirements for service portability are still

undefined.

Wireline Local Number Portability

(LNP) Architecture and Processes

Architecturally, seven basic components are required

to deploy local number portability (LNP):

• Service order administration (SOA)

• Number portability administration center (NPAC)

• Local service management system (LSMS)

• Service control point management system (SCP MS)

• Number portability database (NPDB)

• Signal transfer point (STP)

• Service switching point/mobile switch center

(SSP/MSC)

Service Order Administration

(SOA)

• Serves as an interface element between carriers'order and provisioning systems and the NumberPortability Administration Center (NPAC).

SOA's primary functions include

• subscription audit request or management

• data administration, data transfer to the NPAC

• report generation

• bulk file parse and upload

• subscription tracking

• legacy order entry interface

• logging.

Number Portability Administration Center (NPAC)

• This database is designed to receive information from

both the incumbent and new service providers, validate

the information received, and download the new routing

information when an activate message is received

indicating that the customer has been physically

connected to the new service provider’s network.

• The NPAC also maintains a record of all ported

numbers and a history file of all transactions relating to

the porting of a number.

• The NPAC provides management, administration,

oversight, and integration of NPAC operations,

hardware and software development, and all

maintenance-related functions.

Local Service Management System

• The Local Service Management System (LSMS) is afault-tolerant hardware and software platform thatcontains database with routing information to portedtelephone numbers.

The primary functions of the LSMS are

• subscription management

• network data management

• service provider data management

• error processing and notification

• transaction event logging and reporting

• transmission of activation/deactivation events to thenetwork elements, and audits.

Service Control Point

Management System (SCP MS)

• The Service Control Point Management System

(SCP MS) provides interface services between the

LSMS and the SCP

• The SCP MS may or may not be physically

integrated with the SCP.

Number Portability Database

• The Number Portability Database (NPDB)

contains all ported numbers within a ported

domain as well as routing info. necessary to

support number portability.

• Its function is to provide the association between

the called party and the carrier LRN, identifying

the switch to which the call should be routed.

Signal Transfer Point (STP)

• It receives the LRN query from the SSP/MSC

and routes the query to the appropriate LNP SCP.

• It returns the SCP response to the SSP/MSC.

Service Switching Point/Mobile

Switch Center (SSP/MSC) • It is owned and operated by the exchange

carrier.

• These switch points must be able to generate a

LNP query to the NPDB when a call is placed to

a telephone number in a ported domain.

Telecommunications

management network (TMN) Architecture for the seven LNP components.

CALL FLOWWire line To Ported Wirelined Number

1. A wireline customer calls a wireline ported no.

2. No. not found on SP-1, so a query is launched by

SSP to SSP 1’s Database to know the LRN of the

ported no.

3. A query is not required if

• The called party DN is served by the switch.

• The call is routed to an operator system or

interexchange carrier.

• A NP query was already made for the call

• The serial triggering limit is exceeded.

4. The call is routed to LRN of the ported no. , SP 2’s

Switch.

5. SP 2 terminates the call to the ported no.

CALL FLOW

BenefitsType 1 Benefits

..Accrue to subscribers who retain their telephone number

when switching an operator, and include cost savings from having to

change number. Such subscribers are able to avoid the costs of

reprinting stationary, informing callers, changing signs and lost

business.

Type 2 Benefits

..Are those that arise out of efficiency and service quality

improvements and any associated price reductions resulting from

increased competition.

Type 3 Benefits

..Are those that accrue to callers to porting users who are able

to avoid the need to change entries in their diaries, directories,

databases and abbreviated dialers. They would also dial fewer wrong

numbers and make fewer directory inquiries

Conclusion

• Brings challenges and opportunities for old and new

telecommunications providers.

• To be successful in the competitive

telecommunications environment, carriers have to

carefully analyze their network and administrative

infrastructures, select the best NP solution for their

needs and exploit the benefits of increased customer

choice that NP provides.

• Brings choice to the end-users without the

inconvenience of changing their numbers.

References1. Measuring the Benefits of Number Portability: Sean Lyons

Department of Economics Trinity College Dublin, Ireland:

http://www.tcd.ie/Economics/TEP/2006_papers/TEP9.pdf

2. Number Portability (NP): VeriSign Communications Services:http://www.verisign.com/stellent/groups/public/documents/white_paper/001950.pdf

3. Number Portability: Sysmaster:

www.sysmaster.com/brochures/number_portability.pdf

4. Number Portability Administration Center

(NPAC):http://www.npac.com/

5. The Impact of Wireless Number portability Regulations:

Maggie Lee, Senior Technical Analyst on Local Number

Portability,Illuminet:

http://www.mobilein.com/The%20Impact%20of%20Wireless

%20Number%20Portability%20Regulations.pdf