What?
What is ENUM?
ENUM is an internationally approved method for connecting the telephone communications network to the Internet. ENUM is designed to enable you to call someone on different electronic communications devices and software applications by using a single identifier – a telephone number converted into a domain name.
Initial benefits of ENUM
The first main use of ENUM will be to link different VoIP servers so that telephones within businesses that use Voice over Internet Protocol (VoIP) technology to connect users within an internal network can use the same technology to connect users to external customers via the Internet.
At present it is easy to connect from one employee within a company to another in the same company using a VoIP server. That still works if an employee is a home worker who connects over the Internet – the VoIP server recognises the numbers within its system and connects the call as if the home worker were in the office.
However, if someone within Company A wishes to connect to someone in Company B using their VoIP server currently, they need to connect to a telephone network provider who makes the connection to the other company. Obviously this costs money, as the calls are charged for by the telephone company.
The advantage of ENUM is that it will enable Company A’s VoIP server to connect with Company B’s VoIP server via the Internet without having to connect to the telephone network for the call.
This is done by translating the telephone number into a domain name:-
01865 332211 becomes 1.1.2.2.3.3.5.6.8.1.4.4.e164.arpa where ‘44′ is the UK’s international dialling code, ‘e164′ is the name of the telephone numbering system and ‘.arpa’ is the Internet infrastructure equivalent of .uk or .com. A computer can understand and connect to this address in a fraction of a second which makes ENUM a quick, stable and cheap link between the telecommunications system and the Internet.
Future benefits of ENUM
As the technology develops, local control of the information associated with your ENUM domain name will enable calls to be connected to your desk telephone or mobile ‘on the fly’ as you move in and out of the office environment.
For example, you could save all your contact details: fax and phone numbers (work, mobile and home), e-mail and home addresses, voicemail etc. all in one ENUM entry. This address is used to store Name Authority Pointer Records (Naptr), that contain whatever contact details you wish to include, such as mobile telephone number, landline telephone number, fax, web site address and email address. You can then add rules to redirect people to one or other of these contact details depending on who the person is, what time it is and so on. For example calls after 5.30pm could be routed to your mobile, whilst all contacts during office hours could be via e-mail.
Industry and Government working together
The Department of Trade and Industry (DTI) are overseeing the ENUM project in the UK in consultation with industry experts, service providers, future subscribers, users and those with a general interest in electronic communications.
The DTI’s involvement is primarily to ensure the proper handling of ‘rights of use’ of telephone numbers and domain names. Currently the telephone and Internet address systems – the Public Switched Telephone Network (PSTN) and Internet Protocol (IP) networks – are operated in very different ways.
Telephone numbers are allocated by governments in accordance with strict International Telecommunications Union (ITU) recommendations and the Domain Name System via a series of bodies such as the Internet Corporation for Assigned Names and Numbers (ICANN). When these systems are joined there is the potential for considerable confusion, hence the government’s involvement.
Self-regulation
However, the DTI does not want to impose regulation from above, but rather establish some form of management arrangements for the UK part of the proposed ENUM system. Their preferred solution would be a system of self-regulation to ‘avoid the need for legislation and to let the system develop on a commercial basis that allows for open and fair competition whilst protecting the public interest.’
This approach is consistent with current Government policy not to regulate the allocation and use of the Internet identifiers on which ENUM relies. It also accords with the trend in Europe and the UK towards greater liberalisation and self-regulation for electronic communications.
ENUM trials are being conducted in a growing number of countries and whilst it does have many benefits, such as improved Voice over Internet Protocol (VoIP) or using the Internet to make telephone calls, it also raises a number of issues.
The fact that it is being implemented on a country-by-country basis means that many of the decisions that are being taken will be applied from a national rather than an international perspective leaving many areas of policy open to interpretation.
Privacy
There are also a number of potentially far-reaching data protection and privacy implications, which have been cause for concern in some countries, and which the DTI openly acknowledges will need to be addressed.
For instance, a telephone number and therefore an ENUM is a globally unique identification number. Because of the convenience of using a single number to contact another person, ENUM is also of huge potential interest to marketers and spammers and would be a prime target for the data mining of personal contact information, especially given that all numbers would be held in one international public database.
For this reason the ENUM Security and Privacy Task Group was set up to established a framework of Fair Information Practices (FIPs) but these have yet to be tried and tested on a large scale.
Next steps
So where next for ENUM? Nominet has been awarded the contract to run the UK Tier 1 registry to look after and run the ENUM database.
We hope to launch UK ENUM in Summer 2008.
This page was originally written by Nominet: http://www.nominet.org.uk/tech/enum/
