Telephone numbers, actually session addressing, is one of the major issues, problems, or opportunities in telecom, depending on your point of view. Along with so-called Net Neutrality, it is one of the critical battles being waged in the quest for a competitive communications market. It is a major concern to many telecom strategists because it partitions session-addressing universes: the traditional telecom universe (10-digit (E.164) numbers), SIP addressing, the Skype universe (your Skype ID), the Google universe (your G-Mail account), and so on (Yahoo!, AOL, MSN, etc.).
There is an emerging international standard, ENUM, that is modeled on the Internet’s Domain Naming System (DNS). ENUM maps 10-digit telephone numbers to Internet address resources via an ENUM server.
In the US, you must be a legal “telephone company” to get a block of telephone numbers to assign to subscribers, Skype, Google, and AOL chose to develop their own schemes to identify a user. So, except for Google, which uses a protocol, XMPP, that supports addressing-server federation, each of these services is an addressing island, reducing the value of each network compared with its value to the user if all addresses can be reached, regardless of network. Currently, each of these network developers jealously guards their control of addressing on their network.
Ten-digit telephone numbers that are within the North American numbering plan are administered by NeuStar, Inc, the North American Numbering Plan Administrator (NANPA). Assignments are made based on the central office designated by the carrier, which is hopelessly antiquated for the Internet age. The carriers have an interest is keeping this system in place for as long as possible since it allows them to exert some degree of market control (they own the numbers). (Actually, with number portability, you own the number, but it can only be transferred between telcos.)
Not only is this system exclusive, it is country-specific, and, it is specifically designed to support the legacy model of the country-specific telecom monopoly. The ITU, an agency of the UN, administers the country codes. However, Skype, for example, wasn’t and isn’t interested in national borders. Except in a few countries, the Internet is a global platform, and Skype needed a global session-addressing scheme. It had one sitting on the shelf from the company’s Kazaa origins, and it used it.
However, there is an emerging international standard, ENUM, that is modeled on the Internet’s Domain Naming System (DNS). ENUM maps 10-digit telephone numbers to Internet address resources via an ENUM server. The ENUM server provides the requesting client (for example, a SIP proxy) with the stored information, such as the subscriber’s VoIP SIP address, fax address, e-mail address, or other resources, such as secondary addresses, to services to which the number’s owner has subscribed. The network operated by Telecom Austria (which uses Commetrex’ BladeWare), has had ENUM in commercial operation since December 2004.
Although ENUM, especially carrier-owned private ENUM, still pays its respects to the established order, the extensible nature of the information (Internet resources) provided by ENUM servers can effectively decouple the location of value-adding services from the provision of transport. So don’t expect carriers to warmly embrace ENUM, as it makes service invocation seamless.
There’s been plenty of discussion lately in the US about how to foster innovation. All the US Congress needs to do to insure that market forces in telecom will continue to support innovation is to ensure an open, national ENUM system similar to the one in Austria.
If you want to know more about what Commetrex is doing to “Make FoIP Work,” give us a call.