The Internet Assigned Numbers Authority
) is the entity that oversees global IP address allocation
, root zone management
for the Domain Name System
(DNS), media types
, and other Internet Protocol
related assignments. It
is operated by the Internet Corporation for Assigned Names and
Numbers, better known as ICANN
the establishment of ICANN for this purpose,
IANA was administered primarily by Jon
Postel at the Information Sciences
Institute at the University of Southern
California, under a contract USC/ISI had with the United States
Department of Defense, until ICANN was created to assume the
responsibility under a United States
Department of Commerce contract.
IANA is broadly responsible for the allocation of globally-unique
names and numbers that are used in Internet protocols that are
published as RFC
These documents describe methods, behaviors, research, or
innovations applicable to the working of the Internet and
Internet-connected systems. IANA also maintains a close liaison
with the Internet
Engineering Task Force
(IETF) and RFC Editorial team in
fulfilling this function.
In the case of the two major Internet namespaces
, namely IP
and domain names
administrative policy and delegation to subordinate administrations
is required because of the multi-layered distributed use of these
IANA delegates local registrations of IP addresses to Regional Internet Registries
(RIRs). Each RIR allocates addresses for a different area of the
world. Collectively the RIRs form part of the Number Resource Organization
formed as a body to represent their collective interests and ensure
that policy statements are coordinated globally.
IANA delegates the allocation of IP
to RIRs in large blocks. The RIRs sub-allocate
smaller blocks in their regions to Internet service providers and
other organizations. Since the introduction of the CIDR
system, IANA typically allocates address space in
the size of '/8' prefix blocks for IPv4
since the deployment of IPv6
, '/12' prefix
blocks from the 2000::/3 block to requesting regional registries as
IANA administers the data in the root
, which form the top of the hierarchical DNS tree.
This task involves liaising with top-level domain
operators, the root
nameserver operators, and ICANN's policy making apparatus.
ICANN also operates the .int
international treaty organizations, the .arpa
zone for Internet infrastructure purposes, including reverse DNS
service, and other critical zones such as root-servers.net.
IANA administers many parameters of IETF
protocols. Examples include the names of Uniform Resource Identifier
(URI) schemes and character
recommended for use on the Internet. This task is
undertaken under the oversight of the Internet Architecture Board
the agreement governing the work is published in RFC 2860.
managed by the Internet
Corporation for Assigned Names and Numbers (ICANN) under
contract to the United States Department of
The Department of Commerce also
provides an ongoing oversight function, whereby it verifies
additions and changes made in the root to ensure IANA complies with
On January 28, 2003 the Department of Commerce, via the Acquisition
and Grants Office of the National Oceanic
and Atmospheric Administration
, issued a notice of intent to
grant ICANN the IANA contract for three more years. It invited
alternative offerors to submit in writing a detailed response on
how they could meet the requirements themselves. Such responses
were to be received no later than 10 days following publication of
the invitation and the decision on whether to open the "tender" to
competition was to remain solely within the discretion of the
In August 2006, the U.S. Department of Commerce extended its IANA
contract with ICANN by an additional five years, subject to annual
Since ICANN is managing a worldwide resource, but being controlled
by U.S. interests, a number of proposals have been brought forward
to decouple the IANA function from ICANN. However, it is widely
believed that it would be impractical to change the current control
structure without risking fracturing the Internet.
History of IANA
established informally as a reference to various technical
functions for the ARPANET, that the Information Sciences
Institute performed for the Defense Advanced
Research Project Agency (DARPA) of the United States
Department of Defense.
The earliest reference to a registry function is probably RFC 322,
published on March 26, 1972, in which Vint
and Jon Postel
"socket registry". This registry was published as RFC 433 in
The first reference to the name "IANA" in the RFC series is in RFC
1060, published in 1990, but the function, and the term, was well
established long before that; RFC 1174 says that "Throughout its
entire history, the Internet system has employed a central Internet
Assigned Numbers Authority (IANA)...", and RFC 1060 lists a long
series of earlier editions of itself, starting with RFC 349.
In 1996 the "DNS Wars" began as the FNAC ordered the NSF to
instruct its contractor, Network Solutions who ran the Internic
project, to begin charging for com/net/org domain names. There was
widespread dissatisfaction with this concentration of power (and
money) in one company and people looked to IANA for a solution.
Postel wrote up a draft on the creation of new top level
USC/ISI would not back Postel in the legal sense and IANA, which
was a part time "task" had no legal personality - it could not sign
contracts - and there was some resentment in the community at
paying IANA large sums of money to add one or two lines to the
legacy root zone. Jon was trying to institutionalize IANA.
Postel was threatened by Ira Magaziner when he split the root zone,
assuming authority for the entire domain name system in an attempt
to repatriate the root to IANA; Jon had plans to add hundreds of
new tlds, a plan he had advocated for a while. This would let him
do it, however it lasted less than a day.
managed the IANA function from
its inception until his death in October 1998. Postel had been
given defacto authority to perform the IANA function, as he had
always done it in his position at the Information Sciences
Institute, under its Department of Defense contract. After his
death, Joyce Reynolds
, who had
worked with him at IANA for many years, managed the transition of
the IANA function to ICANN.
Starting in 1988, IANA was funded by the U.S. government under a
contract between the Defense Advanced
Research Projects Agency
and Information Sciences
(ISI). This contract expired in April 1997, but was
extended to preserve IANA's function.
- On December 24, 1998, USC entered into a transition agreement
with the Internet Corporation for Assigned Names and Numbers
ICANN, transferring the IANA function to
ICANN, effective January 1, 1999, thus making IANA an operating
unit of ICANN.
- On February 8, 2000, the Department of Commerce entered into an
agreement with ICANN to perform the IANA functions.
- In June 1999, at its Oslo meeting, IETF
signed an agreement with ICANN concerning the
tasks that IANA would perform for the IETF; this is published as
- In November 2003, Doug Barton was
appointed IANA manager.
- In 2005, David Conrad
was appointed as IANA manager.