ENUM
ENUM (Electronic Numbering) is a protocol developed by the Internet Engineering Task Force (IETF) wherein the the Domain Name System (DNS) might be used to identify available services associated with E.164. ENUM involves the process of creating a domain name from a telephone number and resolving it to an internet address or Uniform Resource Identifier (URI) using the DNS technology and the hosting of ENUM domain names on the E.164 arpa domain.[1]