ATIS 0300073-2003 Report on NANP D Digit Release Final Document.pdf

1、 ATIS-0300073 REPORT ON NANP D DIGIT RELEASE January 24, 2003 Copyright 2003by the Alliance for Telecommunications Industry Solutions, Inc. All rights reserved. The Report on NANP D Digit Release dated January 24, 2003 (former document number INC 03-0110-31) is copyrighted, published and distributed

2、 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, without the prior express written permission of ATIS. Participants in the INC and other part

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4、, 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 standards development organization committed to the rapid development of global, market-dr

5、iven 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 Networks, Energy Efficiency, IP-Based and Wireless Technologies, Quality of Service, and Billin

6、g and Operational Support. In addition, numerous Incubators, Focus and Exploratory Groups address emerging industry priorities including “Green”, IP Downloadable Security, Next Generation Carrier Interconnect, IPv6 and Convergence. ATIS is the North American Organizational Partner for the 3rd Genera

7、tion 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 Commission (CITEL). For more information please visit . - The Industry Numbering Committe

8、e (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 within the NANP area. This document is maintained under the direction of ATIS and the INC. S

9、uggestions 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 to this document shall be made through the INC issue resolution process and adopted by the

10、 INC as set forth in the ATIS Operating Procedures. - Notice of Disclaimer the values of 0 and 1 may not be assigned in this position. This restriction allows the assignment of 80% of the CO codes in all NPAs. D digit release is the effort required to redefine the CO portion of the NANP to allow the

11、 use of 0 or 1 in the D digit position. If the D digit restriction is eliminated, it could result in the availability of up to 200 additional CO codes for each NPA. Service Providers (SPs) have always needed additional codes in the NANP format to perform other functions. None of these additional cod

12、es are dialable by telephone users. Since the values 000-199 are not part of the assignable NANP numbers for either of the first two codes, these values can be used for the additional functions, (e.g., Inward Operator Codes, Industry Test Codes, Emergency Services Indicator Digit, etc.). SPs have de

13、fined requirements for switching and billing systems to detect when these values appear unexpectedly. The industry has used these D-digit codes for both inter SP purposes as well as intra SP applications. Within this report these uses will be categorized. An indication will also be given if their co

14、ntinued use would cause a conflict to the industry even if the numbers are not dialed over the PSTN. An underlying assumption in INCs work on the expansion of the NANP has been the release of the D digit coincident with NANP expansion. This is necessary to effect a transition in which both the exist

15、ing and the expanded numbers can be dialed by using the historic D digit as a trigger. Release of the D digit would permit any digit value from 0-9 to be used in that position. The objective of this report is to identify and investigate the technical impacts of D digit release. The FCC discussed the

16、 release of the D digit in the “Second Report and Order, Order on Reconsideration in CC Docket No. 96-98 and CC Docket No. 99-200, and Second Further Notice of Proposed Rulemaking in CC Docket No. 99-200”, FCC 00-429 released December 29, 2000. The FCC directed carriers to begin identifying and elim

17、inating specialized uses of 0 and 1 as the D digit in anticipation of the eventual release of the D digit. 2.0 Identified Industry Uses of D Digit In order to identify the impacts of D digit release, it is necessary to have a clear understanding of the myriad ways in which NANP formatted numbers wit

18、h 0 or 1 as the D-digit are used in telecommunication networks. It is useful to distinguish between intra- and inter-service provider applications. This distinction is important because, if and when the D digit is released, it will be up to individual carriers to determine how to replace D digit res

19、ources being used for intra-service provider applications. The industry must agree on how to replace D digit resources in inter-service provider applications. Within inter-service provider applications, it is also necessary to distinguish uses that are network related from those that are operator su

20、pport system related. 2.1 Network Applications Examples of current network applications of 0/1XX Central Office codes include: 2.1.1. Test Codes Seven-digit Test Numbers Seven-digit test numbers that begin with the CO codes 167, 181, 182, 183, 195, 198, 199, represent an intra-service provider appli

21、cation using the D digit. Any number can be used for test purposes so there should be ample opportunity to migrate off of these specific codes in the future. Should these codes be maintained as is they will represent a conflict with assigned numbers once the D digit is released. 10X Test Line Codes

22、Three digit addresses of the form “10X” are in widespread use sending calls to standard test lines. The codes 100, 102, 105, 108 and 109 are currently the most widely used. These 10X codes are used alone as the address in either MF or SS7 trunk signaling, and are not normally, but may in some cases,

23、 be combined with an NPA code. 10X codes are normally used only when the destination switch is a tandem, and are not usually sent to local offices. In areas where D digit release would be used, a restriction prohibiting the use of 7-digit numbers would be needed for trunk groups that expect the 10X

24、test codes. This use represents an inter-service provider application of the D digit since the testing can be conducted between two switches one being a tandem switch. Since this testing can be done on a ten digit basis, it may be best to then assign some of these numbers for test purposes within th

25、e 100, 102,105, 108 and 109 codes. This would allow all the rest of the numbers to be assigned for normal purposes. Carriers receiving CO code or thousands block assignments containing numbers reserved for testing would need to make these numbers unavailable for assignment to end users. 2.1.2. Billi

26、ng Numbers Marine Identification Numbers CO Codes in the 0/1XX format are used as billing numbers for marine originated traffic (ship to shore). These are called Marine Identification Numbers. This use represents an inter-service provider application. If an alternative is not adopted before D digit

27、release continued use of these codes could potentially represent an ambiguity for billing systems since there will also be assigned numbers with identical CO codes on billing tapes and call detail records. INWATS and OUTWATS CO Codes in the 0/1XX format are used as billing numbers for both INWATS an

28、d OUTWATS lines. These numbers are usually in the format of 00X-XXXX for INWATS and 01X-XXXX for OUTWATS. This use represents an intra-service provider application. If an alternative is not adopted before D digit release continued use of these codes could potentially represent an ambiguity for billi

29、ng systems since there will also be assigned numbers with identical CO codes on billing tapes and call detail records. Special Billing Numbers CO Codes in the 0/1XX format are used as special billing numbers for PBX/Centrex. These special billing numbers are recorded in switch Automatic Message Acco

30、unting (AMA) records and receive special treatment in downstream systems. In the case of OUTWATS they also control certain aspects of call processing that determine whether a given call can be placed. These numbers may be signaled between switches but are not passed between networks. These uses of t

31、he D digit represent a set of intra-service provider applications. If an alternative is not adopted before D digit release, continued use of these codes could potentially represent an ambiguity for billing systems since there will also be assigned numbers with identical CO codes on billing tapes and

32、 call detail records. 2.1.3 Pseudo Numbers Pseudo numbers in the format 0XX-XXXX are sometimes assigned to Automatic Call Distributor (ACD) groups to conserve “real“ numbers. These numbers are always associated with a “real“ lead number and are never directly dialed by subscribers. These numbers are

33、 used within a given switch. If the switch software does not differentiate this application from actual dialed numbers, then this intra-service provider application may represent an ambiguity to the switch software and these pseudo numbers may not be identified in a different manner than actual assi

34、gned numbers that will have the same digits. Given this situation, the continued use these pseudo numbers cannot be supported. 2.1.4 Feature Group D 0ZZ and 1NX Codes 0ZZ1and 1NX codes appear in the first stage of MF signaling for FGD inter-exchange calls. Many Operator Services trunk groups, as wel

35、l as E9-1-1 systems, still use MF signaling. Historically, the 0 and 1 were chosen as leading digits to avoid conflict with the 2-9 leading digits of both 7-digit and 10-digit telephone numbers. In areas where D digit release would be used, a restriction prohibiting the use of 7-digit numbers would

36、be needed for MF FGD signaling. This is likely to be a significant issue only in LATAs that are single-NPA, since trunks would normally be arranged for 10-digit addresses in multi-NPA LATAs. These codes are used for both intra- and inter-service provider applications. 2.1.5 Caribbean Codes 0/1XX Cen

37、tral Office codes are used in the Caribbean for a variety of purposes including, USA direct dialing, international inbound 800, and some operator services. If these intra- or inter-service provider applications create a situation where assigned CO codes using the released D digit create conflicts, t

38、hen other codes will be required that are not conflicting. 10ZZ codes, used for trunk group selection in MF signaling, are drawn from spare Toll Center Codes, see Telcordia Technologies GR-690-CORE, Exchange Access Interconnection FSD, Section 3.1.1.2.1 Issue 2, October 1996. 2.1.6 Emergency Service

39、s Some wireless Emergency Services Routing Digits and Emergency Services Routing Keys (ESRD/ESRK)2make use of numbers with a 0/1 D digit since the intent has been to avoid use of normal assignable NANP resources for this purpose. There may also be instances where 0/1 D digit numbers are used for rou

40、ting to a Public Safety Answering Point (PSAP) in order to have a non-dialable number so as to protect the PSAP from mis-dialed or maliciously placed calls. These applications are intra-service provider and will need to be changed. There are a number of alternatives that are already used in wireless

41、 networks that can replace this approach. 2.1.7 Virtual Private Network (VPN) Routing The Modification of Final Judgement (MFJ) allows telephone companies to offer Central Office Based telephone systems for end users. These systems are pseudo-PBXs. Part of this service routes simulated private netwo

42、rk traffic over the PSTN. In order to distinguish the private network traffic from the normal PSTN traffic, these systems use routing digits in the format of the Codes 000-199. These codes get routed across networks and complete in customer facilities by distinguishing the routing codes differently

43、from normal 7 or 10 digit PSTN routing. These VPN facilities are accessed by dialing an access code which takes the end-user directly to the service provider carrier providing the VPN service. The VPN traffic is then mixed with PSTN traffic and crosses the service provider network. At the terminatin

44、g end, the switching system interprets the routing digits to complete to another end-user as if the call was switched by a private network. This is an intra-service provider application and will need to be assessed within each service provider network to determine if there is a conflict between VPN

45、routing codes and NANP CO codes having the D digit released. 2.2 Operator Support System Applications Examples of current operator support system applications of 0/1XX Central Office codes include: 2.2.1 Operator Services Inward Routing The LERG shows over 1,000 telephone locations assigned in Area

46、Codes 886 and 889 as not being dialable by any customer. These locations can only be reached via telephone company operators. Calls are completed operator-to-operator using Inward Routing. Operators route calls to one another for functions such as inward Busy Line Verification (BLV), hard to reach n

47、umbers, non-dialable numbers, etc. The dialing pattern is NPA-TTC-OSDC, 2See Telcordia GR - 145 - CORE, Compatibility Information for Interconnection of a Wireless Services Provider and a Local Exchange Carrier Network, Issue 2, May 1998. where NPA is the area code (Number Plan Area), TTC is the Ter

48、minating Toll Center, and OSDC is the Operator Special Dialed Code. OSDCs are 3- to 5-digits in length. The inward calls are routed on an NPA-TTC basis when calls are placed between operator systems. An operator might not have to dial the NPA if the operator was going inward to an operator system wi

49、thin its home NPA. Toll Center Codes, having the format 0/1XX, are preceded by the NPA, and are listed in the Telcordia3LERG4. The LERG Routing Guide shows the total number of active NPA-Access Tandem Code (ATC) combinations in service. Of those codes, it indicates how many fall into the 0XX and 1XX categories and their respective values. It a