Before I respond more fully to Roberto, I wanted to mention that DNS is
used for many things beyond simply looking up IP addresses.
For example, in Internet telephony (H.323), one of the ways of expressing
the callee is using what looks like an e-mail address. The part of the
callee name after the "@" is used in a DNS query to obtain a TXT record
which, in turn, references a "gatekeeper" for the callee's H.323 zone.
That is just one of several ways in which DNS is being used for things
well beyond mapping of names to IP addresses.
We have to be aware of these uses of DNS and not wear blinders about DNS
like WIPO did.
I also want to mention that in these days of web caches and other forms of
proxy devices, DNS queries are often captured and manipulated in order to
re-aim a client to a more convenient server for a particular service. In
those situations, which are becoming, increasingly common, DNS is being
used as sort of a yellow pages service lookup rather than a white pages
address lookup.
--karl--
