What is ENUM?
ENUM is the way to map telephone numbers as specified in the ITU E.164 standard into the DNS
IETF created the ENUM standard – RFC 2916[bis]
e164.arpa initially delegated to the RIPE NCC, the RIPE NCC operates the domain on behalf of the IAB
Liaison statement between IAB and ITU-T on how delegations are made under e164.arpa