ATIS 0300071-2001 Recommended Plan for Expanding the Capacity of the North American Numbering Plan (NANP).pdf

1、 ATIS-0300071 RECOMMENDED PLAN FOR EXPANDING THE CAPACITY OF THE NORTH AMERICAN NUMBERING PLAN (NANP) December 13, 2001 Copyright 2001 by the Alliance for Telecommunications Industry Solutions, Inc. All rights reserved. The INC Recommended Plan for Expanding the Capacity of the NANP dated December 1

2、3, 2001 (former document number INC 02-0107-029) is copyrighted, published and distributed by ATIS on behalf of the Industry Numbering Committee (INC). Except as expressly permitted, no part of this publication may be reproduced or distributed in any form, including electronic media or otherwise, wi

3、thout the prior express written permission of ATIS. Participants in the INC and other parties are hereby authorized to reproduce this document and distribute it within their own business organizations for business purposes, provided that this notice continues to appear in the reproduced documentatio

4、n. Resale is prohibited. For ordering information, please contact: ATIS 1200 G Street N.W., Suite 500 Washington, DC 20005 (202) 628-6380 incatis.org A complete listing of INC Documents is available on the ATIS Web Site at: http:/www.atis.org/inc/docs/.asp ATIS is the leading technical planning and

5、standards development organization committed to the rapid development of global, market-driven standards for the information, entertainment and communications industry. More than 250 companies actively formulate standards in ATIS 18 Committees, covering issues including: IPTV, Service Oriented Netwo

6、rks, Energy Efficiency, IP-Based and Wireless Technologies, Quality of Service, and Billing and Operational Support. In addition, numerous Incubators, Focus and Exploratory Groups address emerging industry priorities including “Green”, IP Downloadable Security, Next Generation Carrier Interconnect,

7、IPv6 and Convergence. ATIS is the North American Organizational Partner for the 3rd Generation Partnership Project (3GPP), a member and major U.S. contributor to the International Telecommunication Union (ITU) Radio and Telecommunications Sectors, and a member of the Inter-American Telecommunication

8、 Commission (CITEL). For more information please visit . - The Industry Numbering Committee (INC) provides an open forum to address and resolve industry-wide issues associated with planning, administration, allocation, assignment and use of North American Numbering Plan (NANP) numbering resources wi

9、thin the NANP area. This document is maintained under the direction of ATIS and the INC. Suggestions for improvement of this document are welcome. They should be sent to the Alliance for Telecommunications Industry Solutions, INC Staff, 1200 G Street NW, Suite 500, Washington, DC 20005. All changes

10、to this document shall be made through the INC issue resolution process and adopted by the INC as set forth in the ATIS Operating Procedures. - Notice of Disclaimer ii) portability with pooling will at a minimum cover the top one hundred MSAs in the U.S.; iii) portability and pooling are restricted

11、to a rate center; iv) portability will apply to all geographic numbers used in a wireline/wireless environment; v) location portability may eventually need to be supported throughout any given portability pooling area and will not be restricted to rate centers; and vi) While service provider portabi

12、lity refers to the ability of end users to retain the same telephone number as they change from one service provider to another, service portability refers to the ability of users of telecommunications services to retain existing telecommunications numbers without impairment of quality, 7reliability

13、, or convenience when switching from one telecommunications service to another service (i.e. POTS to ISDN) provided by the same telecommunications carrier. r) The N restriction (i.e., 2 through 9) will be removed from the existing D digit in the Central Office (CO) code field coincident with the imp

14、lementation of the NANP expansion plan. s) The conditions defined in the INC Uniform Dialing Plan4will be implemented before the NANP expansion plan is implemented. 4See INC Uniform Dialing Plan, INC 97-0131-017, www.atis.org/atis/clc/inc/incdocs.htm 83.0 Selection Process/Considerations The NANP Ex

15、pansion Workshop dedicated a number of meetings to evaluating options for NANP expansion. The objective of the meetings was to identify the best candidates by comparing their relative ability to meet specific assessment criteria with the expectation of recommending a specific expansion plan to the i

16、ndustry. This resulted in fewer viable options at each stage in the selection process. Details and the rationale regarding the elimination of plans are documented in the NANP Expansion Reference Document. Initially, each option was evaluated against the assumptions and constraints (see Annex B and C

17、). The next phase was an evaluation using the assessment criteria described below. When a given option failed to meet this evaluation, the rationale for elimination was documented. For example, if a proposed alternative used symbols and digits rather than just the digits 0-9, the plan did not meet t

18、he basic assumptions and constraints and was subsequently rejected. In addition, each option was evaluated against assessment criteria relating to such items as: increased usable capacity in numbers; basic human factors; consistency with international standards, etc. When a given option failed to me

19、et this evaluation, the rationale for elimination was documented. For example, plans that added capacity to an irrelevant portion of the number (i.e. in the station/line number field) were rejected. As indicated in row one of Table 1 below, some of the options were eliminated based on the fact that

20、they conflicted with the Assumptions and Constraints that INC had established. The results of the evaluations are captured in meeting notes and correspondence and recorded in either Annex B or C of the Reference Document. Row two of the table shows that other options satisfied the Assumptions and Co

21、nstraints, but failed to meet critical Assessment Criteria. The justification for these decisions is documented in Annex B and C of the Reference Document. Row three indicates options that were eliminated using a matrix approach. During this evaluation, INC ranked each option under each category of

22、Assessment Criteria on a comparative basis that resulted in the elimination of a number of options. The rationale for the elimination of these is documented in Annex F of the Reference Document. Row four indicates options that were subjected to a second phase of numerical matrix evaluation that were

23、 eliminated based on their relative inability to satisfy the Assessment Criteria, and they are documented in Annex C of the Reference Document. Row five references the Pro/Con analysis that led INC to five potential options documented in the Interim NANP Expansion Report dated December 10, 1999. 9Af

24、ter the issuance of the Interim NANP Expansion Report the remaining five options were evaluated (see row six of the table), which were later reduced to two potential alternatives. This phase of the evaluation was based on a more detailed analysis of transition issues, most notably “zero plus” dialin

25、g conflicts. The details of this evaluation are documented in Annex B of the Reference Document. At this point, INC had two plans left to consider. One of the plans added one digit to the NPA code (called plan 1A) and the other added two digits to the existing NANP (one digit to the NPA and the othe

26、r digit to the CO code, referred to as 1B). At the same time INC received a suggestion from the FCC regarding the concept of only adding one additional digit to the central office code. INC then decided to accommodate all these options into one recommendation that supported the addition of one or tw

27、o additional digits to the NPA or CO code fields. This resulted in the present plan being recommended. Table 1: High Level View of the Selection Process Type Documentation Source Evaluation Basis: Additional Documentation 1. Reject upon Summary Evaluation Annex B and C in Reference Document Conflict

28、 with Assumptions and Constraints Meeting Notes and Correspondence 2. Further Evaluate and then Reject Annex B and C in Reference Document Passed Assumptions and Constraints but Failed Assessment Criteria 3. Phase I Annex F in Reference Document Passed Assessment Criteria and Matrix Phase I Captured

29、 in Matrix 4. Phase II Annex C in Reference Document Passed Matrix Phase II and Pros it will simply provide more NPAs to relieve those nearing exhaust. Expanding the CO code field by adding a digit in front of it will achieve an eleven-digit NANP, but will require mandatory and universal eleven-digi

30、t dialing. However, the latter approach will provide sufficient CO codes (7000 per NPA instead of todays 800) to reduce and, in most cases, possibly eliminate the need for NPA relief. While a major benefit of Method 3 in comparison to Method 2 is the elimination of future NPA splits/overlays in the

31、first phase of NANP expansion, its implementation will only effectively work if a significant number of unassigned NPAs are still available in the industry pool. In order to ensure that adequate NPAs will be available for future industry needs, Method 3 will have to be started in a timeframe that is

32、 much earlier than that needed for Methods 1 or 2. The earlier starting timeframe required for Method 3 runs counter to one of the primary goals of the industry: to delay any NANP Expansion plan as long as possible in order to avoid the cost and service impacts associated with this major undertaking

33、. The cost impacts associated with the necessary network changes and the impacts on the entire NANP end user community associated with this Method 3 will be no less than the impacts associated with any other NANP expansion plan. To proceed with Method 3, policy-makers, the industry, and the public m

34、ust prepare for expansion well in advance of the point at which all available NPAs had been assigned. 21Method 1 combines the benefits of adding resources to each NPA, deferring the need for NPA relief, adding additional NPAs, as well as allowing NANP expansion to be deferred as long as possible. Me

35、thod 1 also minimizes the number of expansion conversions the public and industry would have to endure. 4.5.1 Comparison Summary The following table provides a comparison of the three NANP Expansion methods. Table 2: Comparison Table of Transition Methods NPA(X) (X)NXX XXXX Features Method 1 (Both N

36、PA this is referred to as releasing the D digit. Releasing the D digit will require clearing all uses of the 0 and 1 in the D digit position (e.g., to support internal routing, identification and billing functions, etc.). The network must be able to accurately and ubiquitously deal with numbers dial

37、ed when the central office code begins with a 0 or 1 NANP format (e.g., NPA XXX XXXX) before any of these numbers are assigned to subscribers. It is recognized that the current use is extensive and therefore steps must be taken to eliminate it prior to the rollout of NANP expansion to ensure success

38、ful and on-time implementation of NANP expansion. The FCC stated in its Second Report and Order: “We therefore direct carriers to begin identifying and eliminating specialized uses of zero or one as the D Digit in anticipation of the eventual expansion of the D Digit.”10An evolution scenario for exp

39、ansion is depicted below in Table 3. 10FCC 00-429, Paragraph 106. 235.1.1 Timeline Table 3 provides a timeline for NANP expansion. This timeline, which will be applicable to phase one of any of the three transition methods described in this report, is based on a starting point identified as Year X.

40、Section 5.2, which describes how the trigger is determined for each expansion method, will set the Year X starting point. If a multi-phase transition is chosen, then the second phase would start over at step one. The overall timeframe for NANP expansion starting from starting from Year X will be ten

41、 years with various milestones defined throughout this ten-year period. Table 3: NANP Expansion Plan Timeline STEP ACTIVITY/MILESTONE DATE/TIMING 1 NANP expansion trigger reached Year X 2 Recommend NANP cut-over relief date Year X 3 Regulatory approval of NANP cut-over date Year X 4 Notify industry,

42、 media, and public Year X 5 Commence expansion implementation Year X - Commence clearing of D-digit - Commence implementation of ten-digit dialing 6 D-digit cleared Year X + 5 7 Ten-digit dialing in place Year X + 5 8 Commence expansion deployment in network Year X + 6 9 NANP cut-over Year X + 9 - C

43、ommence permissive dialing 10 Commence assigning expanded format Year X + 9 numbers 11 Terminate permissive dialing Year X + 10 12 Additional NANP resources available for Year X + 10 assignment 245.1.2 Transition Interval INC recommends an implementation interval for expansion of one year. This tran

44、sition interval is effectively the permissive dialing period during which callers would be able to complete calls by dialing either the current NANP format or the expanded NANP format. This period would provide sufficient time for worldwide notice that the dialing plan for the NANP would be changing

45、 and also permit a concentrated and focused public education program to capture the publics attention for such a major change in telecommunications. This interval would provide time for a concerted effort to identify and resolve the inevitable problems associated within the introduction of new desig

46、n. A longer transition period would run the risk of weakening public awareness and preparedness. In addition, the ability of switching equipment around the world to enable two dialing protocols for NANP numbers for a term much longer than a year is likely to be problematic. INC supports the same tra

47、nsition interval of one year for all expansion methods. Nevertheless, the transition interval may also be impacted by human factors that INC has not studied. Consequently, the length of this interval constitutes another policy issue that NANP nation decision makers should address. 5.2 Triggers NANP

48、Transition Methods 1 and 2 initially expand the NPA field, whereas NANP Transition Method 3 initially expands the NANP by increasing the CO code field. Based on the different approaches utilized by each method, different triggers will need to be defined that will determine the unique starting timeframe for each method. In addition, Methods 2 and 3 describe approaches increasing the NANP in two phases. After the first phase is implemented there will need to be another decision point or trigger tha