Progress achieved towards implementing electronic numbering "ENUM"

Geneva, 1 October 2001 — The International Telecommunication Union (ITU) has achieved further progress in advancing work to enable the commercial implementation of an Internet telephone number mapping protocol, better known as ENUM. Study Group 2 of ITU’s Telecommunication Standardization Sector is currently hammering out the principles and procedures for the administration of ENUM as well as the framework that will set out the role of ITU. Under the proposed ENUM protocol and subject to national authorities and end-user approval, it will be possible to use a single number to access many types of terminal(s) and services — phone, fax, e-mail, pager, mobilephones, SIP telephony address, a website or any other resources that can be described by an Internet addressing scheme — at home, at work or while roaming.

"The work plan agreed by Study Group 2 responds to requests from industry and Internet standardization groups, while satisfying government regulatory concerns", said Roy Blane, Chairman of Study Group 2. "We now have an agreed path forward that will allow, when the work is completed, an orderly and secure way for many new services to be provided, for example the ability to call a voice-enabled IP terminal from a conventional telephone. This is a clear example of convergence, and the ITU is playing a major role in making it possible. At the same time it is a clear demonstration of the ITU’s commitment to promote at the international level the adoption of a broader approach to the issues of telecommunications in the global information economy, in line with the ITU Constitution".

Developed in cooperation with the Internet Engineering Task Force (IETF), ENUM proposes to make available seamless access among the fast growing number of communication devices that use different types of networks (circuit-switched and packet switched including IP) and different numbers and addresses by mapping a single number to these addresses through the Internet Domain Name System (DNS). For example, the number +41 22 123 4567 would become 7.6.5.4.3.2.1.2.2.1.4.E164.TLD, where the number is written backward with the E164.TLD at the end. The "E164.TLD" stands for an Internet top level domain, which has yet to be formally approved by ITU-T. The "E164" stands for the ITU-T Recommendation E.164, which defines the international public telecommunications numbering plan. When using ENUM, users will need to only enter telephone numbers: the reversing of digits and conversion into the DNS will be performed by software.

Two key applications that ENUM will make possible for the first time is the ability to call a PC from the public-switched telecommunication network (PSTN) and to easily determine what type of terminal is associated with the number. Some analysts predict that this will permit the introduction of new innovative applications where a call to a telephone number can invoke Internet type services. For example, calling an ENUM-enabled telephone number from a 3rd generation multimedia handset could start a location-based mobile web service — avoiding entering Internet-type addresses on numeric keypads. Another possible application of ENUM is the support of dynamic routing of certain types of calls, say those from a friends or "buddy" list to a higher priority device such as a mobile or a pager. The potential of ENUM is driven by the integration of different addressing systems used in the PSTN and Internet worlds, for those who wish to avail themselves of this option.

The ENUM protocol was first defined by the IETF, who then requested that ITU perform certain administrative functions related to the actual implementation of the protocol. ITU and IETF experts have been working together to define the exact details of these administrative tasks, which have, in certain cases, regulatory implications given that the protocol spans both the public international telecommunication and Internet realms, which are often subject to different regulatory regimes. In keeping with the need to allow for a voluntary implementation of the scheme and while recognizing that ENUM services are primarily national issues, rapid progress in the work at the international level is considered important to creating a stable environment in which investment can be made in the worldwide deployment of ENUM.

A first draft of the Recommendation detailing the role of ITU in the administration of ENUM is now being circulated to all ITU-T Members for comments. The text proposes to define the boundaries between the administrative and operational aspects of ENUM at both the national and international levels, excluding the technical operation of the DNS, which is outside the scope of the Recommendation. The text is expected to be reviewed at the next meeting of an expert group of Study Group 2 in February 2002 and to reach sufficient stability in May 2002 for potential approval in November 2002 under the traditional approval process (TAP).

TAP is the formal approval process applicable for Recommendations having policy or regulatory implications. Under this procedure, a consultation of the Member States takes place to determine whether a Study Group is assigned the authority to give the draft Recommendation final approval ("decision") at its next meeting. The text becomes effective at the time of final approval if the approval procedure is unopposed.

The International Telecommunication Union (ITU) is a global organization where the public and private sectors cooperate for the development of telecommunications and the harmonization of national telecommunications policies. Study Group 2 of the ITU Telecommunication Standardization Sector (ITU-T), where work on ENUM is being carried out, is the Lead Study Group on Service definition, Numbering, Routing and Global Mobility and is responsible for the operational aspects of service provision, networks and performance. More information on the ENUM protocol, and the issues related to it, can be found at www.itu.int/osg/spu/infocom/enum/.

The Internet Society — a professional membership society with more than 150 organizational and 6,000 individual members in over 100 countries — is home for the groups responsible for Internet infrastructure standards, including the Internet Engineering Task Force (IETF) and the Internet Architecture Board (IAB). The Internet Engineering Task Force is an international community of network designers, operators, vendors, and researchers concerned with the evolution of the Internet architecture and the smooth operation of the Internet. The definition of the ENUM protocol, as proposed by the IETF can be found at www.ietf.org/rfc/rfc2916.txt

For further information, contact:

About ITU