Mark Foster
Internet Draft Tom McGarry
<draft-foster-e164-gstn-npusa-01.txt> James Yu
NeuStar, Inc.
Category: Informational February 9, 2000
Number Portability Administration in the U.S.
Status of this Memo
This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026 [RFC].
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1. Abstract
This document provides a historical as well as practical overview of
the implementation of Number Portability (NP) Administration in the
United States (U.S.). There are various regulatory constraints that
establish relevant parameters for NP implementation, most of which
are not network technology specific. This document describes the NP
business model and the architecture for NP administration in the
North America. It also briefly discusses the functions performed by
the NP administrator and the cost recovery mechanism.
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Number Portability in the GSTN: An Overview February 9, 2001
1. Background
The North American telecommunications industry began to seriously
investigate methods of providing local number portability (LNP) in
late 1994. On July 13, 1995, the Federal Communications Commission
(FCC) in the U.S. issued a Notice of Proposed Rulemaking (NPRM) FCC
Docket Number 95-116 that opened discussion on NP and sought
comments on a wide variety of policy and technical issues related to
NP.
In 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 NP in their respective
states. After considerable discussion and deliberation, the
"Location Routing Number (LRN)" scheme was selected by Illinois, and
other states. The switching and signaling requirements for number
portability developed in the Illinois LNP workshop under the
auspices of the ICC became the basis of the de facto North American
industry standards [ICC]. The activities on number portability in
the North America also interacted with activities in many other
parts of world.
2. Abbreviations and Acronyms
ACQ All Call Query
AIN Advanced Intelligent Network
CRTC Canadian Radio and Television Commission
FCC Federal Communications Commission
ICC Illinois Commerce Commission
IETF Internet Engineering Task Force
LEC Local Exchange Carrier
LLC Limited Liability Corporation
LNP Local Number Portability
LRN Location Routing Number
LSMS Local Service Management System
NANC North American Numbering Council
NP Number Portability
NPAC Number Portability Administration Center
NPDB Number Portability Database
NPRM Notice of Proposed Rulemaking
OSS Operation Support System
PUC Public Utility Commission
QoR Query on Release
RBOC Regional Bell Operating Company
SMS Service Management System
SOA Service Order Administration
SS7 Signaling System Number 7
STP Signaling Transfer Point
TN Telephone Number
URL Universal Resource Locator
U.S. United States
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Number Portability in the GSTN: An Overview February 9, 2001
3. Performance/Legal/Regulatory Requirements
After substantial industry discussion and debate, and extensive
comments filed with the FCC, the FCC and the U.S. telecommunications
industry set the following minimum performance criteria for LNP:
1. Support existing network services, features and capabilities.
2. Efficiently use numbering resources.
3. Not require end users to change their telecommunication numbers.
4. Not require telecommunications carrier to rely on databases,
other network facilities, or services provided by other
telecommunications carriers in order to route calls to proper
termination point.
5. Not result in unreasonable degradation in service quality or
network reliability when implemented.
6. Not result in unreasonable degradation of service quality or
network reliability when customers switch carriers.
7. Not result in a carrier having a proprietary interest.
8. Be able to accommodate location and service portability in the
future.
9. Have no significant adverse impact outside areas where number
portability is deployed.
In July 1996, the FCC issued the First Report and Order on LNP under
95-116, calling for the deployment of LNP across the U.S. starting
in 1997. The FCC did not mandate any specific implementation of LNP
in the U.S., but it did call upon the industry to develop and
endorse a national standard that would ensure interoperability with
all industry segments, including wireless. While providing overall
guidelines and requirements for LNP, it did explicitly state that
the LRN method met these requirements, whereas alternate proposals
(such as Query on Release or QoR) did not.
A core requirement was that a carrier who is serving ported numbers
need not be reliant on any other carrier (especially the donor
network) for completing calls, whether for call transport/routing or
for signaling. That's not to say that a carrier couldn't
voluntarily opt to use another carrier or the donor network for
queries or call routing. But the key is voluntarily. This
requirement was imposed on all NP implementations in the U.S. for
common carrier telephony services regardless of the network
technology employed.
Similar requirements were adopted by the Canadian Radio and
Television Commission (CRTC), the equivalent of the FCC in Canada,
and in a number of regulatory and industry bodies in other countries
(e.g., Belgium, Denmark, Spain, and Switzerland) which resulted in
the use of centralized Number Portability Databases (NPDBs) to
support number portability.
In the U.S. and Canada, the All Call Query (ACQ) scheme was adopted
because it does not rely on the donor network for call routing (see
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Number Portability in the GSTN: An Overview February 9, 2001
requirements numbers 4 and 7) and it can accommodate location and
service portability in the future.
In the U.S. and Canada, there is also the "N-1" guideline that
recommends that the network next to the destination network perform
the NPDB query if the NPDB query has not been done or the routing
information is not available (e.g., due to signaling interworking).
This is to prevent the call from being re-routed at the donor
network. In the U.S., the wireline carriers are required to support
NP in certain service areas in phases. The wireless carriers'
support of NP has been postponed until November 2002.
4. NP Administration Process in the North America
4.1 Business Model
Figure 1 shows the NP business model that was adopted in the U.S.
and Canada. The U.S. is divided into seven regions coinciding with
the boundaries of the original seven Regional Bell Operating Company
(RBOC) regions. This was done to facilitate the formation of
separate contracting and administrative areas (formed as limited
liability companies) for LNP in the U.S. intentionally coinciding
with the original RBOC boundaries, thus enabling each RBOC to
participate singly in each of these areas.
A contractor was selected in open competitive procurements conducted
by the industry to be the Number Portability Administration Center
(NPAC) provider for each of the seven NPAC regions (Midwest,
Northeast, Mid-Atlantic, Southwest, Southeast, Western, and West
Coast) in the U.S. The same thing happened in Canada as well. Each
Limited Liability Corp. (LLC) in the seven U.S. regions and Canadian
Consortium maintain largely identical contracts with the selected
contractor(s) covering each region.
The FCC and North American Numbering Council (NANC) oversee the
technical and operational standards and cost recovery rulemakings.
The state Public Utility Commissions (PUCs) also influenced the
development of technical and operational standards.
Each LLC signed a master contract with the selected NPAC that set the
prices and terms and provided the form of User Agreement for the
selected NPAC to sign with each individual NPAC user. NPAC users are
any bona fide entity that either ports numbers or subscribes to
updates to the NPDB provided by the NPAC.
Before becoming a NPAC user, a Customer must first sign and return a
Non-Disclosure Agreement before any other documentation can be sent.
Therefore after the NPAC receives a signed Non-Disclosure Agreement
the Customer can now receive the Master Agreement, User Agreement,
and Interconnect Plan. The Master Agreement is the top-level
overall contract.
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Number Portability in the GSTN: An Overview February 9, 2001
+--------+ +----------+
| FCC |------------>| State |
| NANC |<---+ +--->| PUCs |
+--------+ | | +----------+
| |
v v (Master
+--------------+ Agreement) +----------+
| Regional LLC |<----------->| NPAC |
| Contract | | |
| Administrator| +----------+
+--------------+ ^
^ |
| |
v |
+----------+ |
| NPAC |<------------------+
| Users | (One User Agreement per User)
+----------+
Figure 1. NP Administration Business Model in the U.S.
The User Agreements come under the Master Agreements and must be
signed by the individual Customers who wish to use NPAC services.
If a Customer plans on operating in more than one region, the
Customer must sign a separate User Agreement for each of the regions
where operations will take place.
The Interconnect Plan is another NPAC document that the Customer
must sign and return. This document provides an overview of the
customer interconnection to the NPAC.
The new customer process is shown below.
- Customer contacts Chicago NPAC (Help Desk) to request information.
- Introduction Package (Application, Non-Disclosure Agreement) sent
to customer.
- Customer signs and returns Non-disclosure Agreement.
- Master Agreement, User Agreement and Interconnect Plan sent to
Customer.
- Customer signs and returns User Agreement.
- Customer signs and returns Interconnect Plan.
- Customer data entered.
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Number Portability in the GSTN: An Overview February 9, 2001
4.2 NPAC Architecture
Figure 2 shows the architecture for number portability
administration in the U.S. and Canada.
(Carrier Facilities) : (NPAC Facilities)
:
+---------+ :
| SOA | :
| |-------------------+
+---------+ : |
: |
: +----------+
: | NPAC/SMS |
: | |
: +----------+
: |
+---------+ +---------+ : |
| NPDB |---------| LSMS |-------------------+
| | | | :
+---------+ +---------+ :
:
Figure 2. NPAC Architecture.
The interface between the Service Order Administration (SOA) and the
NPAC/SMS (Service Management System) is for provisioning ported end-
user data including the support of the creation, cancellation,
retrieval and update of subscription, service provider, and network
information. The local exchange carriers operate the SOAs.
The interface between the Local Service Management System (LSMS) and
the NPAC/SMS is mainly used for downloading ported number
information from the NPAC/SMS to the LSMS. The LSMS then updates
the NPDB. A local exchange carrier may operate the LSMS if it
decides to deploy an NPDB itself. A service bureau can also operate
the LSMS to provision several Local Exchange Carriers' (LECs') NPDBs
or operate the LSMS and the NPDB for the operators (e.g., LECs or
long distance carriers) to query. The interface between the LSMS
and the NPDB is up to the entities that operate them.
The functional requirement specification developed under the
auspices of the North American Numbering Council (NANC) defines the
external functionality of the NPAC SMS [FRS]. The interfaces
between the NPAC/SMS and the SOA or LSMS use standards-based
communications and security technologies and are made public [IIS].
Please note that only the information about the ported numbers is
stored at the NPAC databases and the NPDBs at present.
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Number Portability in the GSTN: An Overview February 9, 2001
4.3 NPAC SMS Functions
This section provides a list of the NPAC SMS functions. Please see
[FRS] for details.
- Provisioning Service: For the new service provider to notify the
NPAC SMS of a provision request for a ported number and to send an
activation notice to activate the update from the NPAC SMS to the
LSMS.
- Disconnect Service: For handling disconnection of the telephony
service for a ported number.
- Repair Service: For resolving problems detected either by a Service
Provider or by a customer contacting a Service Provider.
- Conflict Resolution: For resolving a conflict when there is
disagreement between the old and new Service Providers as to who
will be providing service for the telephone number (TN). Please
note that the processes for obtaining authorization from the
customer to port a number are defined by the Service Providers.
The NPAC is not involved in obtaining or verifying customer
approval to port a telephone number.
- Disaster Recovery and Backup: For having a backup facility and the
disaster recovery procedures in place for planned and unplanned
downtime at the primary facility.
- Order Cancellation: For the new Service Provider to cancel a
previously submitted but not activated provision request.
- Audit Request: For troubleshooting customer problems and also as a
maintenance process to ensure data integrity across the entire NP
network.
- Report Request: For supporting report generation for pre-defined
and ad-hoc reports.
- Data Management: For managing network, Service Provider, and
customer subscription data. The network data defines the
configuration of the NP service and network and includes such data
as: participating Service Providers, NPA-NXXs that are portable,
and LRNs associated with each Service Provider. The Service
Provider data indicates who the NP Service Providers are and
includes location, contact name, security, routing, and network
interface information. The subscription data indicates how local
number portability should operate to meet subscribers' needs.
- NPA-NXX Split Processing: For the administration of the
information for NPA split (the current NPA, the new NPA, and the
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affected NXXs) plus the beginning and end date of the permissive
dialing period.
- Business Support: For supporting service providers that have
different needs for business hours and days available for porting.
- Notification Recovery: For allowing a Service Provider to capture,
via a recovery process, all notifications that were missed during
a downtime period for the Service Provider.
4.4 Cost Recovery
In the FCC's Third Report and Order, adopted May 5, 1998, released
May 12, 1998 and published in the Federal Registry July 29, 1998 the
Commission implemented section 251(e)(2) with regards to the costs
of providing long-term number portability. Section 251(e)(2) of the
Communications Act of 1934 (1934 Act), as amended requires that "the
cost of establishing telecommunications numbering administration
arrangements and number portability shall be borne by all
telecommunications carriers on a competitively neutral basis as
determined by the Commission."
The costs can be categorized below.
- Share costs incurred by industry as a whole for the NPACs:
* Non-recurring costs, e.g., administrator costs to implement
database hardware and software.
* Recurring costs, e.g., administrator costs to administer the
databases.
* Costs incurred by administrators to upload and download data to
and from databases. Shared costs of each regional database
distributed among telecommunications carriers with revenue
derived from providing telecommunications service in the area
served by the database, in proportion to carrier's share of
revenue for the region. Carriers without such revenue assessed
$100 per year.
- Carrier-specific costs incurred by each carrier that directly
relates to providing NP, e.g., querying calls, porting telephone
numbers between carriers.
* Dedicated costs, e.g., number portability software, NPDBs and
Signaling Transfer Point (STPs) reserved exclusively for NP.
* Joint costs, e.g., software generics, switch hardware, Operation
Support System (OSS), Signaling System Number 7 (SS7) or Advanced
Intelligent Network (AIN) upgrade, incremental to providing NP.
Carriers may include incremental overhead incurred specifically
in providing NP.
Incumbent LECs may recover costs directly related to providing NP
through federally tariffed charges that can be query-service
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charges, prearranged and default, and monthly end-user charges. For
example, the end-users in the metropolitan D.C. area pay 23 cents
per month for NP surcharge. Carriers, other than incumbent LECs, may
recover costs in any manner consistent with state and federal laws
and regulations.
5. References
[FRS] NANC, "Functional Requirements Specification - NPAC SMS,
Version 2.0.2," September 1, 1999.
[ICC] ICC, "Generic Switching & Signaling Requirements for Number
Portability, Issue 1.05," August 1, 1997.
[IIS] NeuStar (formerly Lockheed Martin IMS Corporation), prepared
for the North American Numbering Council (NANC),"NPAC SMS
interoperable Interface Specification, Version 2.0.2,"
September 1, 1999.
[RFC] Scott Bradner, RFC2026, "The Internet Standards Process --
Revision 3," October 1996.
6. Author's Addresses
Mark D. Foster
NeuStar, Inc.
1120 Vermont Avenue, NW,
Suite 550
Washington, D.C. 20005
United States
Phone: +1-202-533-2800
Fax: +1-202-533-2975
Email: mark.foster@neustar.com
Tom McGarry
NeuStar, Inc.
1120 Vermont Avenue, NW,
Suite 550
Washington, D.C. 20005
United States
Phone: +1-202-533-2810
Fax: +1-202-533-2975
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Number Portability in the GSTN: An Overview February 9, 2001
James Yu
NeuStar, Inc.
1120 Vermont Avenue, NW,
Suite 550
Washington, D.C. 20005
United States
Phone: +1-202-533-2814
Fax: +1-202-533-2975
Email: james.yu@neustar.com
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