ENUM Heads for Primetime

After some months in the wilderness, ENUM (electronic number mapping), the protocol that maps telephone numbers to IP addresses, is once again a hot topic as VOIP providers look for ways to charge customers for new services and keep their calls off the PSTN.

ENUM, or e164.arpa, uses a lookup system for routing that’s similar to the domain name system (DNS) for Web addresses. It can allocate a single number that can then be used for multiple IP services, such as VOIP, email, instant messaging, and so on.

Then, if you enter a phone number into your cellphone or PDA, the ENUM software delivers information about all the possible ways to contact the owner of that number (call, email, instant message, and so on). The user would then choose one of those connections and be charged appropriately.