DSTI/ICCP/TISP(2004)2/FINAL 

TOP LEVEL DOMAIN MARKET STRUCTURE 

ICANN 

The Internet Corporation for Assigned Names and Numbers (ICANN) is an internationally organized, 

non profit corporation that has responsibility for Internet Protocol (IP) address space allocation, protocol 

identifier assignment, gTLD and ccTLD name system management, and root server system management 

functions.

5

 These services were originally performed under United States Government contract by the 

Internet Assigned Numbers Authority (IANA) and other entities. ICANN now performs the IANA 

functions under Transition Agreements and Implementation Agreements.

6

 ICANN was created through a 

Memorandum of Understanding (MoU) between the United States Department of Commerce and ICANN 

to transition management of the Domain Name System (DNS) from the United States government to 

private sector Internet stakeholders. The United States Government effects such privatisation by entering 

into agreement with and seeking international support for a not for profit corporation formed by private 

sector Internet stakeholders to administer DNS policy.

7

Following reforms introduced by ICANN, the gTLD market can be broadly characterised along the 

following lines. Registries perform back office functions and provide services to Registrars. Registrars, in 

turn, provide services to users. Many ccTLDs are also structured along these lines while others have direct 

sales, from the registry to users, without the use of registrars. There are also important distinctions between 

sponsored and unsponsored TLDs as well as those domains that compete in the same space and those that 

serve more limited communities. Before looking at the market shares for TLDs it is necessary to briefly 

summarise the position of various players in the registry and registrar segments of the market. 

Registries 

The responsibility for operating each TLD (including maintaining a registry of the domain names 

within the TLD) is delegated by ICANN to a particular organization. These organisations are referred to as 

 registry operators  or  sponsors . Currently, the gTLDs of 

.aero

, 

.biz

, 

.com

, 

.coop

,  

.info

, 

.museum

, 

.name

, 

.net

, 

.org

 and 

.pro

 are in use, and the corresponding registries are under contract 

with ICANN (

Table 3

). Separate arrangements apply to 

.edu

, 

.mil

, 

.gov

, under United States Government 

responsibility, and 

.int 

which is directly under ICANN's responsibility.

8

 10