Call me...on DNS
DNS has proven incredibly versatile and scalable in resolving email, web, and application services names to IP addresses across the global Internet for over three decades. And its versatility seems to have no limits as DNS can even be used to map telephone numbers into IP addresses too. The means to perform this mapping function is useful for voice applications, not to mention other generic applications requiring resolution with one or more layers of indirection. The ENUM (E.164 telephone number mapping) service has been defined to support telephone number resolution. ENUM supports the mapping of telephone numbers, in ITU E.164 format, into uniform resource identifiers (URIs). A URI is an Internet identifier consisting of a uniform resource name (URN) and a uniform resource locator (URL). A simple example: for URL http://www.ipamworldwide.com with URN file.txt, the corresponding URI would be http://www.ipamworldwide.com/file.txt. The mapping of E.164 numbers (or other arbitrary domain