Clay Shirky's Writings About the Internet
Economics and Culture, Media and Community, Open Source

The Domain Name System is Coming Apart at the Seams

The Domain Name System is coming apart at the seams. DNS, the protocol
which maps IP addresses like to domain names like, is showing its age after almost 20 years. It has
proved unable to adapt to dynamic internet addresses, to the number of
new services being offered, and particularly to the needs of end
users, who are increasingly using their PCs to serve files, host
software, and even search for extra-terrestrial intelligence. As these
PCs become a vital part of the internet infrastructure, they need real
addresses just as surely as does. This is something the DNS
system can't offer them, but the competitors to DNS can.

The original DNS system was invented, back in the early 80s, for a
distinctly machine-centric world. Internet-connected computers were
rare, occupying a few well-understood niches in academic and
government labs. This was a world of permanence: any given computer
would always have one and only one IP address, and any given IP
address would have one and only one domain name. Neat and tidy and

Then along came 1994, the Year of the Web, when the demand for
connecting PCs directly to the internet grew so quickly that the IP
namespace -- the total number of addresses -- was too small to meet
the demand. In response, the ISPs began doling out temporary IP
addresses on an as-needed basis, which kept PCs out of the domain name
system: no permanent IP, no domain name. This wasn't a problem in the
mid-90s -- PCs were so bad, and modem connections so intermittant,
that no one really thought of giving PCs their own domain names.

Over the last 5 years, though, cheap PC hardware has gotten quite
good, operating systems have gotten distinctively less flaky, and
connectivity via LAN, DSL and cable have given us acceptable
connections. Against the background of these remarkable improvements,
the DNS system got no better at all -- anyone with a PC was still a
second-class citizen with no address, and it was Napster, ICQ, and
their cousins, not the managers of the DNS system, who stepped into
this breech.

These companies, realizing that interesting services could be run off
of PCs if only they had real addresses, simply ignored DNS and
replaced the machine-centric model with a protocol-centric
one. Protocol-centric addressing creates a parallel namespace for each
piece of software, and the mapping of ICQ or Napster usernames to
temporary IP addresses is not handled by the net's DNS servers but by
privately owned servers dedicated to each protocol -- the ICQ server
matches ICQ names to the users' current IP address, and so on. As a
side-effect of handling dynamic IP addresses, these protocols are also
able to handle internet address changes in real time, while current
DNS system can take several days to fully log a change.

In Napster's case, protocol-centric addressing merely turns Napster
into customized ftp for music files. The real action is in software
like ICQ, which not only uses protocol-centric addressing schemes, but
where the address points to a person, not a machine. When I log into
ICQ, I'm me, no matter what machine I'm at, and no matter what IP
address is presently assigned to that machine. This completely
decouples what humans care about -- can I find my friends and talk
with them online -- with how the machines go about it -- route message
A to IP address X. 

This is analgous to the change in telephony brought about by mobile
phones. In the same way a phone number is no longer tied to a
particular location but is now mapped to the physical location of the
phone's owner, an ICQ address is mapped to me, not to a machine, no
matter where I am.

This does not mean that the DNS system is going away, any more than
landlines went away with the invention of mobile telephony.  It does
mean that DNS is no longer the only game in town. The rush is now on,
with instant messaging protocols, single sign-on and wallet
applications, and the explosion in peer-to-peer businesses, to create
and manage protocol-centric addresses, because these are essentially
privately owned, centrally managed, instantly updated alternatives to

This also does not mean that this change is entirely to the
good. While it is always refreshing to see people innovate their way
around a bottleneck, sometimes bottlenecks are valuable. While ICQ and
Napster came to their addressing schemes honestly, any number of
people have noticed how valuable it is to own a namespace, and many
business plans making the rounds are just me-too copies of Napster or
ICQ, which will make an already growing list of kinds of addresses --
phone, fax, email, url, ICQ, ... -- explode into meaninglessness. 

Protocol-centric namespaces will also force the browser into lesser
importance, as users return to the days they namaged multiple pieces
of internet software, or it will mean that addresses like
icq://12345678 or napster://green_day_fan will have to be added to the
browsers repetoire of recognized URLs. Expect the rise of
'meta-address' servers as well, which offer to manage a user's
addresses for all of these competing protocols, and even to translate
from one kind of address to another. (These meta-address servers will,
of course, need their own addressses as well.)

Its not clear what is going to happen to internet addressing, but it
is clear that its going to get a lot more complicated before it gets
simpler. Fortunately, both the underlying IP addressing system and the
design of URLs can handle this explosion of new protocols and
addresses, but that familiar DNS bit in the middle (which
really put the dot in dot com) will never recover the central
position it has occupied in the last 2 decades, and that means that a
critical piece of internet infrastructure is now up for grabs.


Thanks to Dan Gilmor of the San Jose Mercury News for pointing out to
me the important relationship between peer-to-peer networking and DNS.

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Economics and Culture, Media and Community, Open Source