Enum VoIP registry goes live in UK

Enum, a VoIP registry service that removes a barrier to pure internet-based calling, went live in the UK on Thursday.

The idea behind Enum is to allow businesses to use standard telephone numbers with their VoIP systems and have calls carried solely over the internet, rather than first being routed over the traditional PSTN network. It works by converting phone numbers dialled by callers into domain names. With that, businesses can present their customers with contact numbers in a familiar, standard format.

The service is run in the UK by Nominet, the national registry for .uk addresses. According to the organisation's director of marketing, Phil Kingsland, Enum will help businesses reduce or eliminate the cost of the calls to suppliers and clients by routing all calls between those parties over the internet.

"We imagine users will be businesses that have large networks that they work with," Kingsland told ZDNet UK on Thursday. "Also, those in the customer-services industry who want to reduce the cost of calls coming in to themselves — if they are advertising an Enum number, their calls would go over the internet for free."

Enum works by reversing a normal phone number, putting dots between the digits and adding 'e164.arpa' onto the end — resulting in a domain. In effect, the service unites the PSTN telephone network with the Domain Name System (DNS), resulting in what Nominet claims is a "quick, stable and cheap link between telecommunications systems and the internet".

Kingsland said a feature of Enum was its ability to have various VoIP providers' networks interoperate. "It enables those islands of VoIP to connect," he said. "If you're using a VoIP system in a company, and you want to connect to another company that has a different system, then this technology enables those calls to be routed appropriately across the internet."

Nominet won the contract to administer the service in late 2007. At that time, the organisation's IT director told ZDNet UK Enum would go live in the spring of 2008.

Asked why Enum's introduction was delayed by a year, Kingsland said it had taken that time to ensure Nominet's registry systems were "capable of running the appropriate registry".

Those companies who are interested in turning their telephone numbers into Enum numbers can do so through one of the registrars listed on Nominet's website. There are currently only three such registrars listed, but Kingsland said he anticipated around 100 registrars to join Nominet's Enum scheme.