Most folks tend to think of the DNS as a way to map ASCII host names to IP addresses, perhaps www.nominum.com to 10.0.01 or some such.
In the case of ENUM and NAPTR, all we are doing is saying that "domain names can carry phone numbers, so why not let them". NAPTR is a DNS data type, so we aren't replacing DNS with NAPTR, that would make no sense. In fact the whole ENUM scheme is built out of classical DNS technology, and NAPTR is really just the latest data type to be added to the DNS (there's 40 or so). NAPTR is also just an extension of SRV, which was an extension of MX, which are DNS data types that Active Directory uses to start itself and the Internet uses to route each piece of mail.
RFID tags, UPC codes, International characters in email addresses and host names, and a variety of other identifiers could all go into DNS, and folks have occasionally proposed doing just that. It's really just a question of figuring out how to use the DNS — it's ready to carry arbitrary identifiers. And by the way, this isn't a new idea, see RFC 1101 for proof, although even earlier I designed the DNS in the early 1980s to allow it to be so, but it seemed too far fetched to document for a while.
But don't think that I'm claiming to have solved the whole problem. What I certainly didn't anticipate was the political, legal, and commercial fight that would come with it. These squabbles behind ENUM and RFID use of DNS are really the problem, not the technology, although there may be ways to help with more technology. I was in Geneva for a WSIS meeting of CTOs, and was surprised that the various organizations (ITU, ICANN, ISOC) haven't figured out that they need each other to make this technology work, rather than asserting ownership.
While it is inevitable that the DNS gets replaced, I think there could be far more usage and opportunity if the political aspects were addressed coherently, and if the technology types just let experimentation happen, rather than trying to make rules about how the DNS is used.
By Paul Mockapetris, Chief Scientist and Chairman
|Cybersquatting||Policy & Regulation|
|DNS Security||Registry Services|
|IP Addressing||White Space|
Minds + Machines