Development and Basis of A.M. Rutkowski International Telephone Numbering VeriSign Inc Document: 21 Mar 2001 Expires: 21 Oct 2001 Development and Basis of International Telephone Numbering Status of this Memo This document is an Internet-Draft and is NOT offered in accordance with Section 10 of RFC2026, and the author does not provide the IETF with any rights other than to publish as an Internet-Draft. However, see Author's Copyright Statement, below. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. Abstract This document describes the development and basis of International Telephone Numbering as it has been manifested through the activities and formal instruments of the International Consultative Committee for Telephony (CCIF) and forums of the International Telecommunication Union (ITU). The current practices for International Telephony Numbering are currently contained in a more general instrument, the International Public Telecommunication Numbering Plan, ITU-T Recommendation E.164 (05/97). The historical record of this activity makes it clear that the basis for telephone numbering has always been that of autonomous sovereign nations and their international public telephony service providers cooperating among themselves to facilitate the routing of calls between their independent national telephony networks. This historical record and basic instruments clearly contradict the notion of a simple authoritative numbering namespace hierarchy governed under the ITU and applied to all instantiations of telephone numbers, such as ENUM-based identifier services in either designated or competitive DNS zones provided using the RFC2916 protocol. Table of Contents 1. Introduction 2. Scope 3. Regional origins (1945-58) 4. Global development (1960-92) 5. Contemporary ITU numbering developments (1993-) 6. Security Considerations 7. References 8. Acknowledgments 9. Author's Address 10. Author's Copyright Statement 1. Introduction The lack of available reference materials concerning the development and bases of International Telephone Numbering frequently results in orthogonal conceptualizations regarding the use of these numbers in resources manifested on private shared user networks that constitute the Internet. In particular, the notions of root-based hierarchical delegations of authority of namespaces such as exist in DNS do not have an equivalent in the international activities or instruments concerning International Telephone Numbering. This is relevant to the provisioning of ENUM services. 2. Scope This is an informational Internet Draft containing the historical record of instruments pertaining to the development and basis for International Telephony Numbering as it might apply to ENUM or any other Internet-based instantiation of those numbers. 3. Regional Origins (1945-1958) It appears that the idea of developing an international telephone numbering plan arose during the London meeting of the International Consultative Committee for Telephony (CCIF) in October 1945. [1] At the time, the CCIF was substantially focused on European telephony networks, and meeting at the end of World War II to modernize the facilities. It adopted an "urgent" Question for the Sub-Commission on Methods of Rapid Operation, calling for the development of principles for what were known as "rapid telephone operations (manual, semi-automatic or automatic)." [2] This subsequently took the form in 1949 of a several year collaborative effort to develop a plan for the interconnection of networks in Europe and the Mediterranean Basin. [3] When the CCIF met in Florence in 1951, it adopted the initial Recommendation of what subsequently became the International Telephony Numbering Plan. It took the form of a set of principles, combined with the specification of the numbers and letters on a standard rotary telephone dial, which was an important predicate for any international plan to work. [4] It also established what became the basic principle for all subsequent work, that each nation independently maintained for its own network a "national numbering plan," but cooperated in the development and implementation of those plans in such a way as to allow international calls. [5] The work at this time proceeded under the aegis of Working Party 2/2 which dealt with matters of telephone Operating and Tariffs. This work culminated in 1954 with the adoption of a new version of the Recommendation establishing for the first time a Rec. 26bis, Numbering Plan for the International Semi-Automatic Telephone Service, complete with an associated List of International Codes for Routing. [6] Two digit codes were indicated for all the countries in five regions: Western Europe, Northern Europe, Central Europe, Balkans and Oriental Europe, and Countries in the Mediterranean Basin. [7] Interestingly, the CCIR also adopted a related recommendation explicitly eschewing a uniform access code since it "would be of use only to the small number of persons who, when travelling abroad would wish to dial a number (under fully automatic conditions) without the assistance of a local inhabitant of the country." [8] At the Special Assembly of the new integrated International Telegraph and Telephone Consultative Committee (CCITT) in 1958, only relatively minor editorial changes were made to the Recommendation which was renumbered to become Rec. E.29, Directives for the Numbering of Subscribers' Lines and for the Routing of Automatic and Semi-Automatic International Working. [9] At the same time, the codes were retitled Numerical List. [10] It is worth noting the editorial changes in the language to emphasize the scope and purpose of the CCITT, leaving each country otherwise independent in "the preparation of a national numbering scheme for its own network." [11] 4. Global Development (1960-1992) In the late 1950s, developments in switching technology and submarine cable deployment led to an interest in developing a global "numbering scheme." The CCITT IInd Plenary meeting - the first CCIT-CCIF-CCITT meeting outside Europe, at New Delhi in 1960 - was the point of embarkation of these seminal developments. The European and Mediterranean Basin number scheme was not significantly changed at the New Delhi Plenary meeting, but it was issued as both Rec. E.29 and Q.11 to reflect the shared responsibility for its future development to the Telephone Signalling and Switching Study Group XI of CCITT. [12] The Plenary established a Special Study Group B on the World-wide Semi-Automatic and Automatic Telephone Network, to "work out the programme of studies to be carried out by the other study groups whose co-operation it requires." [13] SSG-B served as a means both for tasking the other study groups with certain studies, as well as aggregating the work done. The activity to develop a new international numbering scheme was specified in a new Question 2/XIII. [14] Six significant annexes are attached to this Question from Netherlands, Germany, the Chile Telephony Company, Italy, Australia, and AT&T deal with the most important new development - the evolution of the existing numbering scheme from a regional to a global one. A key feature of the transition involved the use of the first digit of the code to indicate a continent for traffic routing purposes. [15] This primary problem with this approach was that a number of countries in the existing European and Mediterranean Basin countries would necessarily be required to shift their national code to another number. The 1964 CCITT Plenary Assembly adopted a revised Rec. E.29 (and Q.11) entitled Numbering for International Working with a List of Country Codes for International Semi-automatic and Automatic Service. [16] Nine World Numbering Zones were designated: 1 (integrated North American numbering plan); 2 (Africa); 3 & 4 (Europe); 5 (Latin America); 6 (Australia and Pacific); 7 (USSR); 8 (East Asia); 9 (Middle East and West Asia). A combination of two and three digit codes necessarily were required. Only seven European countries were able to retain their old codes. Going forward, the Numbering Plan activity was shared among CCITT Study Groups II, XI, and the World Plan Committee. The country code designators were chosen by national operator participants within the World Plan Committee. The 1968 CCITT Plenary Assembly redesignated the Recommendation to E.161 (retaining the Study Group XI copy as Q.11) and retitled the name to Numbering for International Service. The list of codes was expanded to incorporate changes proposed by the World Plan Committee, Mexico City, 1967. [17] The 1972 CCITT Plenary Assembly kept the E.161 and Q.11 designations, but changed the title to Numbering and Dialling Procedures for International Service. The list of codes was expanded to incorporate changes proposed by the World Plan Committee, Venice, 1971. [18] The 1977 CCITT Plenary Assembly kept the E.161 and Q.11 designations and titles the same. The list of codes was expanded to incorporate changes proposed by the World Plan Committee, Geneva, 1975. [19] The 1980 CCITT Plenary Assembly split the numbering recommendation into two parts - redesignating the numbering plan portion to E.163 (also Q.11bis) and changed the title to Numbering Plan for the International Telephone Service. The dial layout part was placed in E.161 and Q.11. The List was expanded to incorporate the changes proposed by the World Plan Committee, Paris 1980. [20] The 1984 CCITT Plenary Assembly kept the Recommendation designation and title the same, Rec. E.163, Numbering Plan for the International Telephone Service. The list was expanded to incorporate the changed proposed by the World Plan Committee, 1984. [21] The numbering plan also ended its dual existence as a Q.11 Recommendation for signalling. The work on the CCITT's Integrated Services Digital Services (ISDN) network also enjoyed a level of development and visibility that resulted the 1984 Plenary adopting Rec. E.164, Numbering Plan for the ISDN Era. [22] This Recommendation did not include the International Telephone Service at this time. The 1988 CCITT Plenary Assembly kept the Recommendation designation and title the same, Rec. E.163, Numbering Plan for the International Telephone Service. The list was expanded to incorporate the changed proposed by the World Plan Committee, 1988.[23] Rec. E.164, Numbering Plan for the ISDN Era was kept the same. [24] In 1991, CCITT Study Group 2 using a special adoption procedure - believing that ISDN would constitute the unifying global network concept - merged Rec. E.163, Numbering Plan for the International Telephone Service, into E.164, Numbering Plan for the ISDN Era. [25] 5. Contemporary ITU numbering developments (1993-) In 1993, the CCITT became the ITU Telecommunication Standardization Sector (ITU-T) and its Plenary Assemblies became World Telecommunication Standardization Conferences. The first was held at Helsinki, 1-12 March 1993. No changes to the telephone numbering plan were made. During the following years, however, International Telephony numbering began to treated more expansively in ITU Study Group 2. This new perspective - that included for the first time Internet developments - manifested themselves at the World Telecommunication Standardization Conference at Geneva in June 1996 (WTSA-96). [26] Of particular note were the pursuit of questions dealing with GII Numbering Requirements (Q20/2), and Impact of Private Networks on E.164 Resources (Q21/2). [27] Consonant with this new perspective concerning numbering, Rec. E.164 was characterized as "the foundation of numbering plans for the public switched network." [28] WTSC-96 was also notable for the first time describing numbering activities in terms of "international numbering resources." This included included working on a new Rec. E.164.1 dealing with "the rules, criteria, and procedures for the assignment of Recommendation E.164 numbering resource." [29] The numbering activity also proceeded toward a less country-focussed and more flexible operator oriented administrative approach that has allowed for many innovative new international services to be offered. However, the use of the term "resources" for benign administrative reasons, could have unintended consequences in other ITU forums. The term's origins go back to the 1970s New World Economic Order (NWIO) political activities of the Non-Aligned Movement that methodically conceptualized radio spectrum, geostationary-satellite orbit positions, and other technical parameters as "resources" necessary to equitably apportion among all the nations of the world. The apportionment method typically included lengthy formal intergovernmental treaty conferences. [30] In late 1998, the ITU Plenipotentiary Conference (Minneapolis, 1988) also advanced the "resources" movement by adopting Resolution 102 characterizing Internet names and addresses as "global and essential resources." [31] This complemented the previous treatment of radio spectrum and the geostationary-orbit as "limited natural resources." [32] Although the Plenipotentiary Conference designated Internet private names and addresses outside their jurisdiction as "resources," they did not do so for the International Public Telephone numbers. Recommendation E.164 was retitled The International Public Telecommunication Numbering Plan in May 1997. [33] Among other reasons, the title change also reflected in large measure the desire to move to a broader, non-ISDN based, conceptualization of numbering. The 1998 Plenipotentiary Conference also changed the name of the ITU-T's quadrennial plenary forums to World Telecommunication Standardization Assemblies. [34] ITU-T also combined its GII and Internet Protocol-Based Network activities in late 1998 with the creation of an IP Coordination Team. [35] The WTSA-2000 met at Montreal, 27 Sep - 6 Oct 2000. Especially notable was the adoption by ITU-T Study Group 2 of Question 1/2, Project number 11 dealing with Naming, Numbering, and Addressing for Interworking between E.164 and IP Address-Based Networks. [36] 6. Security Considerations Because International Telephone Numbering - the principal part of the ITU-T Rec. E.164 used for implementation of RFC2916 (ENUM) [37] - has emerged from the need to route switched circuit based calls between independent autonomous national public telephony networks, the providers of designated and competitive zone ENUM services [38] will likely need to deploy an array of methods to enhance DNS based telephone number zone trust. This autonomy suggests the usefulness of common trust methods such as digital certificates to enhance flexible open market-driven provisioning of ENUM services. 7. References [1] See Comite Consultatif International Telephonique, La XIIIe Assemblee Pleniere du C.C.I.F, CCIF, Paris 1946. The CCIF was one of the two predecessor organizations that were merged together in 1956 to form the International Telegraph and Telephone Consultative Committee (CCITT), which was renamed ITU-T in 1992. Prior to 1949 the CCIF was an independent standards organization based in Paris, and its materials were only available in French. [2] See id at 187. [3] See Programme General d'Interconnexion en Europe et dans le basin Mediteranneen (1949-1942), CCIF, Paris 1949. [4] See VI-2.2 Recommandations Generales Relatives a la Numerotation des Abonnes et a l'Acheminement des Appels, XVIe Assemblee Pleniere, Firenze, 22-27 Octobre 1951, CCIF, Tome VI du Livre Jaune, at 15 (Signalisation dans le service semi- automatique). [5] Idem. [6] See Recommendation No. 26bis, Numbering plan for the international semi-automatic telephone service, CCIF XVIIth Plenary Assembly, Geneva, 4-12 October 1954, Vol. VI Operating and Tariffs, CCIF Green Book, 1954 at 69. [7] Id. at 72-73. [8] See Recommendation 26ter, Code for access to the international network, id at 73. [9] See Recommendation E.29, Directives for the Numbering of Subscribers' Lines and for the Routing of Automatic and Semi-Automatic International Working, CCITT Special Assembly, Geneva, Sept 1958, CCITT White Book, at 36. [10] Id. at 39. [11] Id. at 36. [12] See Recommendation E.29 (also Recommendation Q.11), Numbering of Subscribers' Lines in Automatic and Semi-automatic International Working, CCITT IInd Plenary Assembly, New Delhi, 8-16 December 1960, Vol. IIbis at 38 (Vol. VI at 26), CCITT Red Book, 1961. [13] Id., Vol. Ibis at 106. [14] Id., Vol. VI at 187. [15] Idem. [16] See Recommendation E.29 (also Recommendation Q.11), Numbering For International Working, CCITT IIIrd Plenary Assembly, Geneva, 25 May - 26 June 1964, Vol. II at 98 (Vol. VI at 25), CCITT Blue Book, 1965-66. [17] See Recommendation E.161 (also Recommendation Q.11), Numbering For International Service, CCITT IVth Plenary Assembly, Mar del Plata, 23 Sep - 25 Oct 1968, Vol. IIa (Vol. VI), CCITT White Book, 1969. [18] See Recommendation E.161 (also Recommendation Q.11), Numbering and Dialling Procedures For International Service, CCITT Fifth Plenary Assembly, Geneva, 4-15 Dec 1972, Vol. II-A at 118 (Vol. VI-1 at 28), CCITT Green Book, 1973. [19] See Recommendation E.161 (also Recommendation Q.11), Numbering and Dialling Procedures For International Service, CCITT Sixth Plenary Assembly, Geneva, 27 September - 8 October 1976, Fasc. II.2 at 38 (Vol. Fasc. at 20), CCITT Orange Book, 1977. [20] See Recommendation E.163 (also Recommendation Q.11bis), Numbering Plan for the International Telephone Service, CCITT VIIth Plenary Assembly, Geneva, 10-21 November 1980, Fasc. II.2 at 82 (Fasc. VI.1 at 75), CCITT Yellow Book, 1981. [21] See Recommendation E.163 (also Recommendation Q.11bis), Numbering Plan for the International Telephone Service, CCITT VIIIth Plenary Assembly, Malaga-Torremolinos, 8-19 October 1984, Fasc. II.2 at 104, (Fasc. VI.1 at 113) CCITT Red Book, 1984. [22] See Recommendation E.164 (also Recommendation I.331), Numbering Plan for the ISDN Era, Id. at 111 (Fasc. III.5 at 102). [23] See Recommendation E.163 (also Recommendation Q.11), Numbering Plan for the International Telephone Service, CCITT IXth Plenary Assembly, Melbourne, 14-25 November 1988, Fasc. II.2 at 128, CCITT Blue Book, 1989 (Fasc. VI.1 at 123). [24] See Recommendation E.164 (also Recommendation I.331), Numbering Plan for the ISDN Era, Id. at 135 (Fasc. III.8 at 66). [25] See Recommendation E.164, Numbering Plan for the ISDN Era, Geneva, 1991. [26] See ITU-T Study Group 2, Report to the WTSC-96: Questions Proposed for Study in 1997-2000, Doc 9-E. http://www.itu.int/itudocr/itu-t/wtsc-96/docs1/009_ww7.doc [27] Idem. [28] Idem. [29] See ITU-T Recommendation E.164.1, Criteria and Procedures for the Reservation, Assignment, and Reclamation of E.164 Country Codes and Associated Identification Codes (ICs) (03/98) [30] G. Codding and A. Rutkowski, The ITU in a Changing World, Horizon House, Norwood MA, 1984. [31] ITU, Final Acts of the Plenipotentiary Conference (Minneapolis, 1988) at 274. [32] ITU Constitution, Art. 44, Id. at 22. [33] See Recommendation E.164, The International Public Telecommunications Numbering Plan, Geneva, 05/97; ITU-T Study Group 2 (Network and service operation) Report to the World Telecommunication Standardization Assembly (WTSA-2000): General, WTSA-2000 Document 1 (April 2000) at Annex 5. http://www.itu.int/itudocr/itu-t/wtsa/docs/001_ww9.doc [34] See Art. 18, ITU Constitution, Id. at 28. [35] See ITU-T Study Group 2 (Network and service operation) Report to the World Telecommunication Standardization Assembly (WTSA-2000): General, WTSA-2000 Document 1 (April 2000) http://www.itu.int/itudocr/itu-t/wtsa/docs/001_ww9.doc [36] See ITU-T Study Group 2 (Network and service operation) Report to the World Telecommunication Standardization Assembly (WTSA-2000): Questions Proposed For Study During The Next Study Period 2001-2004, WTSA-2000 Document 2 (April 2000), Annex (to Question 1/2), at 4. http://www.itu.int/itudocr/itu-t/wtsa/docs/002_ww9.doc [37] P. Faltstrom, E.164 number and DNS, RFC1916, Sep 2000. [38] A. Rutkowski and B. Mordecai, Approaches to ENUM Implementation in the USA, Dept of State ITAC-T Advisory Committee, SG-A AdHoc Meeting on ENUM, McLean VA, 12 Feb 2001 http://www.enumworld.com/resources/roadmap.ppt 8. Acknowledgments The author would like to thank the ITU Library and Archives for their kind assistance in providing access to this material, in particular the head of the Service, Kristine Clara. 9. Author's Address for Comments Anthony M. Rutkowski Vice President for Internet Strategy VeriSign, Inc. 505 Huntmar Park Drive Herndon VA 20170 USA mailto:trutkowski@netsol.com tel: +1 703.742.4905 10. Author's Copyright Statement This compilation is expressly placed in the public domain by the author and is available to anyone for any purpose except their assertion of copyright ownership.