Would you like one number for your mobile, landline, fax, net address...

America is lending its support to an international proposal to map telephone numbers to internet addresses.

In a recent internal letter, the George Bush's Commerce Department recommended that the US participate in an emerging electronic numbering system, known as ENUM, that will allow people to use one identifier for many different purposes, including mobile phones, email, instant messaging and faxes. ENUM is designed to accelerate the convergence of the telephone network and the internet and is expected to offer a huge boost to online telephony services.

"The United States should seize this opportunity and take steps to participate in e164.arpa, consistent with the highest standards of security, competition, and privacy," wrote assistant secretary Nancy Victory in the letter to the State Department. The domain that will be used with ENUM addresses ends with e164.arpa.

Victory said the US should formally participate in the ENUM process and push for its implementation, consistent with a set of principles that include supporting competition, minimising regulation, promoting interoperability and preserving privacy.

"Domestic implementation of ENUM must be done in a manner that maximizes the privacy and security of user data entered in the ENUM DNS domain," Victory wrote. "For example, ENUM providers should develop systems to ensure the authentication and authorisation of users who enter and update their personal information."

When ENUM domains become active, users will be identified by their telephone number including the country code. What that means is a phone number such as +46-8-9761234 would be mapped to the 4.3.2.1.6.7.9.8.6.4.e164.arpa internet address in a process that is expected to become automated and transparent to the user.

ENUM grew out of the Internet Engineering Task Force's Telephone Number Mapping working group, which drafted the RFC 2916 proposed standard in September 2000.

So far, 13 countries that are members of the International Telecommunication Union have signed on to the e164.arpa proposal and plan trials. The group is coordinating international efforts.