Re: .COM Clusters are Not RSCs

[Keith Moore <moore at cs.utk.edu>]

> > Another risk is that people will start a 'land grab' on TLDs similar
> > to what's happened with subdomains of .COM.  Any rules for allocating
> > new TLDs that are based solely on competition, whether they be
> > "first-come-first-served" or "my lawyers are bigger than your lawyers"
> > or even "we have nukes, you don't" robs the net community of any hope
> > of reasonable organization of TLD space.
> 
> Easily dealt with.  You can have "N" TLDs (where "N" is some small number,
> say, three or four) until you demonstrate through a public audit process
> that you have at least "X" registrants per TLD in use on average.

That addresses only one of several concerns.  It presumes that someone
has the right to "own" a particular gTLD, if he can sign up some
number of users.  I disagree with that presumption.

> > Another risk is that the number of TLDs will grow so large that TLD
> > queries are no longer likely to be in cache.  This has implications
> > for response time and reliability of DNS, as well as bandwidth usage.
> 
> That's a bald-faced lie.  COM/NET/ORG are on the roots right now.  Forcing 
> NSI to remove them to their own machines, and replacing them with 15,000 
> TLDs (1% of the current load they carry) is the best possible single
> performance improvement we could make in the DNS system.

Read my statement again.  (Hint: I wasn't talking about the load on
DNS servers.)

Right now, everyone has the NS RR for COM in his DNS cache.  Any query
for X.COM only has to go to one server, and only takes one round-trip.
If there were 15,000 gTLDs, chances are that a large number of their
NS RRs would not be cached.  A query for X.Y would thus require
additional round-trips.  Each round trip consumes more network
bandwidth, increases the delay seen by the user, and increases the
opportunity for failure.  

Think about the probability of any particular DNS server failing to
respond (this is a few percent in my experience), multiplied by the
number of different DNS servers that have to be consulted.  Think
about the additional delay seen by the user each time a DNS client has
to time out and fail over to a different server.

This gets even worse if you think in terms of multiple roots because
the logical way for a DNS server to handle an unknown TLD is for it to
search *all* of the roots in some order until it finds an NS RR for
that TLD.  

Now, there are a number of other strategies for distributing DNS gTLD
NS RRs which might alleviate these concerns.  I think these are
interesting and worth exploring.

But it would still be necessary to address other concerns about
pollution of DNS name space that have nothing to do with DNS
performance or reliability.

Bottom line: the technical problems with DNS and large numbers of TLDs
can be solved, though perhaps not without changes to widely deployed
software.  The real problems are in establishing reasonable rules for
creation of new TLDs and in seeing that those rules are adhered to.
These are not technical problems; they're political problems.

The political problems are proving very difficult to solve, largely
because of greedy people who insist on trying to carve out a portion
of TLD space for themselves, at the expense of the net community.  
I have nothing but contempt for those people.

Keith