HTW –
Domain Name Service (DNS) is the critical global directory structure
that drives billions of requests for information on the Internet,
connecting a plain-language address with a unique 32-bit TCP/IP
address. It developed step-by-step from the early ARPAnet systems and
by 1998 was the center of hot debate over control of the Internet.
When the ARPAnet Network Information Center (NIC) was set up at
Stanford Research Institute in 1967 the network didn't need a global
directory. However, as it grew it required lookup tables that were
simply housed in a text file, HOSTS.TXT.
The Domain Name System originally conceived in 1981 was intended to
scale better than a single text file. As funny as it might seem
today, the COMSAT engineer who developed the initial DNS wanted it to
scale to deal with "thousands of hosts." By 1983, the Information
Sciences Institute (ISI) at USC was involved in developing host name
lookups and worked on authority and delegation issues to ease the
burden that the domain name database could place on servers.
The work by the late Jon Postel and Joyce Reynolds became RFC 920,
which in March, 1985 registered the first dot-coms. It also called
for creating the following top-level domains:
* .com, .net, .org, .edu, .gov, .mil, .arpa
* two-letter country top-level domains such as .au, .ca, .uk
In 1991, the U.S. Defense Information Systems Agency sub-contracted
the management of non-military network addresses to Government Systems
Inc. (GSI) and its sub-contractor, Network Solutions, Inc. And by
1994, with the introduction of standards for the World Wide Web and
the first browsers, control of the DNS services had become important –
and a source of revenue for Network Solutions. Which made it
controversial for the next five years.
For more information on the early history of DNS, you can read:
Web Hosting Magazine
"Alphabet Soup: The History of DNS (June, 2001)
http://www.whmag.com/content/0601/dns/
WHAT IS DNS?
The Domain Name System is a database structure that allows computers
to connect plain-language Internet addresses with TCP/IP addresses.
It's decentralized to provide speed and redundancy, which is necessary
when there are hundreds of millions of computers making billions of
requests per day.
By delegating authority, the database can be split among the different
top-level domains. This way, for example, a single company can be
responsible for tracking all .com addresses. And sub-domains can also
be created, giving the webmaster at Microsoft Corp. responsibility for
tracking everything under: microsoft.com
It's an excellent scheme, allowing even more sub-domains and
registration, so that a different server or office might have
responsibility within Microsoft for mail.microsoft.com or an office in
Hong Kong using a domain name like hk.microsoft.com
The top-level domains are registered with a single entity. For .com
domains, Network Solutions still has that responsibility. Twice each
day, domain name servers update the current list of known root name
servers. It looks something like the list published on this page:
How Stuff Works
"How Domain Servers Work" (undated)
http://www.howstuffworks.com/dns5.htm
The architecture specifies that each root server have several backup
servers, so that names can be distributed even if part of the network
is down. It also provides for caching of the names, which is one
reason that changes in Internet addresses sometimes cause problems for
a web page.
The domain servers take care of the full range of Internet functions,
not just World Wide Web addresses. E-mail (POP and SMTP), FTP and
other servers are all identified by TCP/IP address.
HOW IS MY QUERY HANDLED?
When a computer makes a query, say to find answers.google.com, it's
seeking the TCP/IP address. Google would have registered the
google.com domain with a registrar; it will be associated with a
TCP/IP address in the Whois database (www.whois.com).
The ISP's name server may recognize the correct IP address – or it may
request it from another name server. It can also do two other things:
refer you to a name server that's closer to what you're seeking, which
you often see when a particular page in missing or misnamed. Or it
can return an error message.
Finding the sub-domain for answers.google.com will be handled by
Google's name server.
ICANN AND CURRENT MANAGEMENT
As mentioned in the introduction, Network Solutions' management of all
DNS registration functions created controversy because of its
monopoly. Attempts to open up the registration led to the creation of
3 regional bodies in 1997 to manage DNS:
ARIN: American Registry for Internet Numbers
APNIC: Asia-Pacific Network Information Center
RIPE NCC: Reseau IP Europeans
Still the issue remained so thorny that the U.S. Congress stepped in
to investigate. Ultimately the Department of Commerce established
ICANN (Internet Corporation for Assigned Names and Numbers), a
non-profit company. It also provided about $1 million to get it
started in early 2000.
This The White Paper, "Management of Internet Names and Addresses,"
(June 5, 1998) on the United States Department of Commerce, National
Telecommunications and Information Administration website does an
excellent job of summarizing issues at ICANN's formation:
http://www.ntia.doc.gov/ntiahome/domainname/6_5_98dns.htm
ICANN is structured to reach consensus among its various supporting
organization, profiled here in its organization chart (undated):
http://www.icann.org/general/icann-org-chart_frame.htm
But its sponsors are different from its "supporting" organizations.
In November, 2000 the ICANN board authorized seven new top-level
domains: .aero, .biz, .coop, .info, .museum, .name and .pro. Each of
these new domains has "sponsors" which are responsible for creating
policies on registration and use of domain names. For more
information see:
ICANN
New TLDs (Top-level domains) – Sept. 14, 2002
http://www.icann.org/tlds/
CHANGES
The DNS is maturing as ICANN takes over functions previously handled
by Network Solutions (now VeriSign). The most-recent change is the
long-planned handover of database management for .org top-level
registrations, which takes effect at the first of 2003:
ICANN
" .org Agreement Signed; Transition Plans Announced" (Dec. 3, 2002)
http://www.icann.org/announcements/announcement-03dec02.htm
As a public agency responsible for a variety of information interests,
ICANN does a fairly good job of keeping issues out front on its home
page, www.icann.org
Another excellent resource for background on ICANN and DNS issues is
Harvard University's Berkman Center for Internet & Society
"Briefing Book 2000" (Sept. 12, 2000)
http://cyber.law.harvard.edu/icann/pressingissues2000/briefingbook/
Google search strategy:
DNS + history
DNS + function + ICANN + architecture
It's easy to get lost in the terminology and acronyms of these
Internet issues. If you have any questions please don't hesitate to
ask before rating this question.
Best regards,
Omnivorous-GA |
