32-bit ASN – 32-bit Autonomous System Numbers
32-bit Autonomous System Numbers (ASNs) are an update to the original 16-bit ASN format. 32-bit ASNs (also referred to as ASN32s, four-byte ASNs or four-octet ASNs) represent an expansion of the existing ASN numbering space.
AFRINIC – African Network Information Centre
AFRINIC is the Regional Internet Registry (RIR) serving Africa and some countries located in the Indian Ocean.
The range of IP addresses reserved for a Local Internet Registry (LIR) or Internet Service Provider (ISP) for sub-allocation and assignment to End Users or to the LIR’s own network.
APNIC – Asia Pacific Network Information Centre
APNIC is the Regional Internet Registry (RIR) serving the Asia Pacific region.
ARIN – American Registry for Internet Numbers
ARIN is the Regional Internet Registry (RIR) serving Canada, many Caribbean and North Atlantic islands, and the United States.
ASO – Address Supporting Organization
One of the three supporting organizations called for in the ICANN bylaws. The ASO advises the ICANN Board on policy issues relating to the operation, assignment, and management of Internet addresses. As per the ICANN ASO Memorandum of Understanding (MoU) between ICANN and the five RIRs, the NRO, as the coordinating body for the RIRs, fulfils the role of the ASO. The ASO also plays a role in ICANN’s Empowered Community, acting as the Decisional Participant, the Decisional Participant Representative and the Empowered Community Administration Representative. See also: ASO AC, NRO, NRO EC and NRO NC.
ASO AC Chair
The ASO AC member elected at the beginning of each year by the ASO AC to serve as Chair, as per the election procedure outlined in the ASO AC Operating Procedures section 4.4.
ASO AC IC – Address Supporting Organization Address Council Interview Committee
The ASO AC IC forms part of the ICANN Board Seats 9 or 10 selection process as outlined in the ASO AC Operating Procedures section The ASO AC IC is comprised of one ASO AC member from each geographical region and is responsible for conducting interviews with each of the candidates on the ICANN Board Seat 9 or 10 candidate slate and providing a report on each interview to the ASO AC.
ASO AC QRC – Address Supporting Organization Address Council Quality Review Committee
The ASO AC QRC forms part of the ICANN Board Seats 9 or 10 selection process as outlined in the ASO AC Operating Procedures section 9.4.2. The ASO AC QRC is comprised of one ASO AC member from each geographical region and is responsible for reviewing the submissions received after a call for candidates to fill the ICANN Board Seats 9 and 10 has been launched. The QRC reviews submissions received for completeness and for compliance with the eligibility criteria and conflict of interest requirements before accepting or rejecting them.
ASO AC Vice Chair
Each year, the newly elected ASO AC Chair invites two AC members to be Vice Chairs as outlined in the ASO AC Operating Procedures section 4.4.4. The Chair and the two Vice Chairs must all be from different RIR regions. See also: ASO AC Chair.
ASO MoU – Address Supporting Organization (ASO) Memorandum of Understanding (MoU)
An agreement between ICANN and the Regional Internet Registries (RIRs) for forming and operating the ASO
ASO Procedures for for ICANN Empowered Community Powers
The set of procedures that the Address Supporting Organization (ASO) follows during use of the ICANN Empowered Community Powers. See also: ICANN Empowered Community.
ASO Review
Article 4.4.a of the ICANN Bylaws calls for periodic independent reviews of the performance and operation of each of ICANN’s Supporting Organizations by an entity independent of the organization under review. The first independent review of the ASO took place in 2011, the second in 2017.
ASO Secretariat
An entity that provides secretariat and administrative support to the Address Supporting Organization (ASO) and the ASO AC.
ASN – Autonomous System Number
A unique identifier for an Autonomous System (AS) that is used in the exchange of exterior routing. Managed under the RIR system, ASNs were extended in 2009 from 16 to 32 bits in length. See also: 32-bit ASN
A range of IP addresses that is registered for a specific purpose, either for an End User, Internet Service Provider (ISP) or Local Internet Registry’s (LIR) network infrastructure.
See Internet Number Resource Certification (RPKI).
DNS – Domain Name System
The distributed database of information that translates a domain name to an IP address. The DNS also lists the mail servers accepting email for each domain.
DNSSEC – DNS Security Extensions
technology that provides the Domain Name System (DNS) with data integrity and authentication mechanisms, through the use of cryptographic digital signatures.
End User
An entity receiving IP address assignments exclusively for use in operational networks and not for reassignment to other organizations.
GPDP – Global Policy Development Process
The open and transparent process of proposing, developing and accepting global Internet numbering policy, which ensures that the same policy is accepted and implemented in each of the five Regional Internet Registry (RIR) regions. Global policies govern how Public Technical Identifiers (PTI), the organization charged with performing the IANA functions, issues Internet number resources to the five Regional Internet Registries (RIRs). See also: PDP.
IANA – The Internet Assigned Numbers Authority
The entity responsible for coordinating some of the key elements that keep the Internet running smoothly. IANA allocates and maintains unique codes and numbering systems that are used in the technical standards (protocols) that drive the Internet. See also IANA Functions, IANA Numbering SLA, IANA Oversight Transition, IANA RC and PTI.
IANA Functions
The IANA functions are performed by Public Technical Identifiers (PTI). The IANA functions are:

  • Management of the DNS Root Zone (assignments of ccTLDs and gTLDs) along with other functions such as the .int and .arpa zones.
  • Coordination of the global IP and AS number spaces, such as allocations made to Regional Internet Registries
  • Management of the central repository for protocol name and number registries used in many Internet protocols

See also IANA, IANA Numbering SLA, IANA Oversight Transition, IANA RC and PTI.

IANA Numbering SLA (Service Level Agreement)
The IANA Numbering Service Level Agreement (SLA) is held between the IANA Numbering Services Operator (see IANA and PTI) and the five Regional Internet Registries (RIRs) and came into effect on 29 June 2016. The IANA Numbering SLA was developed by the five RIR communities as part of the IANA Oversight Transition. To ensure transparency, each draft of the proposed SLA and any comments were recorded and made available to the public.
IANA Oversight Transition
The transition of the IANA oversight function from the US Government to the multistakeholder community. In March 2014, the U.S government’s National Telecommunications and Information Administration (NTIA) announced its intention to transition the stewardship (oversight) of the IANA functions to the multistakeholder community, something which had been envisaged since ICANN was established. To facilitate the transition, the various communities within ICANN were asked to produce proposals. The Address Supporting Organization (ASO) convened the five RIRs, which worked together as the Numbers Community, to produce a proposal for the IANA Stewardship Transition Coordination Group (ICG) in response to the Request for Proposal (RFP). On 1 October 2016, the contract to perform the IANA functions that was held between ICANN and the NTIA expired, signalling the final step in the community-led transition process. As a consequence, the Service Level Agreement (SLA) for the IANA Numbering Services came into in effect. Oversight of the IANA functions is now the responsibility of the Names, Numbers and Protocol Parameters communities that rely on its services. In some regions, the IANA Oversight Transition is also known as the IANA Stewardship Transition.  See IANA, ICANN Empowered Community, PTI.
IANA RC – IANA Numbering Services Review Committee
The body that advises and assists the NRO EC in its periodic review of the service level of the IANA Numbering Services provided to the Internet Number Community. The IANA RC is composed of two representatives selected by and from each of the five RIR communities and one staff member from each RIR. The IANA RC publishes the IANA Performance Matrix Summary Report during the first quarter of each year. The report pertains to the numbering services that IANA provided to the Numbers community during the previous year. When the IANA Performance Matrix Summary Report is published, a 30-day comment period begins and the five RIR communities are invited to provide input. At the end of the comment period, the IANA RC reviews and summarizes any input received and compiles its final report.
ICANN – Internet Corporation for Assigned Names and Number
The not-for-profit multistakeholder organization dedicated to keeping the Internet secure, stable and interoperable.
ICANN Board Seats 9 and 10
The two seats on the ICANN Board of Directors that are filled by the Address Supporting Organization (ASO) (see section 9.2.a of the ICANN Bylaws). As per section 9.2.b of the ICANN Bylaws the ASO Address Council (ASO AC) is the entity tasked with selecting these persons. The selection procedure used by the ASO AC is outlined in the ASO AC ICANN Board Selection Procedures.
ICANN Empowered Community
The ICANN Empowered Community is the non-profit association formed under the laws of the State of California consisting of the ASO, the ccNSO, the GNSO, the ALAC and the GAC. The ICANN Empowered Community is the mechanism through which these Supporting Organizations (SOs) and Advisory Committees (ACs) can organize to legally enforce their community powers.
The Empowered Community Administration Representative
The administrative body through which ICANN’s Empowered Community acts. Each of the Decisional Participants of the Empowered Community designates one representative to the Empowered Community Administration. The ASO’s designee on the Empowered Community Administration is the current Chair of the Number Resource Organization (NRO), who also acts as Chair of the ASO. The Chair of the NRO/ASO acts only by consensus of all five members of the NRO Executive Council (NRO EC)
ICANN Empowered Community Decisional Participants
The ICANN organizations (ASO, ccNSO, GNSO, ALAC, and GAC) that comprise the Empowered Community.
Empowered Community Decisional Participant Representative
The ASO’s Empowered Community‘s Decisional Participant Representative is the current Chair of the Number Resource Organization (NRO), who also acts as Chair of the ASO. The Chair of the NRO/ASO acts only by consensus of all five members of the NRO Executive Council (NRO EC).
ICANN Empowered Community Powers
The nine community powers and rules that govern the Empowered Community. They are defined in the ICANN Articles of Incorporation and Bylaws. As an ICANN SO, the Address Supporting Organization (ASO) participates in ICANN’s Empowered Community. The ASO has its own set of procedures for exercising the ICANN Empowered Community Powers.
The ICANN Nominating Committee (NomCom). The NomCom is charged with selecting all ICANN officers except the Director and those seats selected by other Supporting Organizations (SOs) and Advisory Committees (ACs). As an ICANN Supporting Organization (SO), the ASO appoints one person to serve on the ICANN NomCom each year. The ASO AC is charged with appointing the ASO’s ICANN NomCom representative and uses the Procedures to Appoint Members to Various Bodies to do so. The ICANN NomCom selection process is separate from the ICANN Board Seat 9 and 10 selection process.
IETF – Internet Engineering Task Force
A global community of network designers, operators, vendors, and researchers concerned with the evolution of the Internet architecture and the smooth operation of the Internet.
IGF – Internet Governance Forum
A global multistakeholder forum to discuss public policy matters and other issues related to the global deployment of the Internet. The IGF was established based on the outcomes of the World Summit on Information Society (WSIS).
Internet Governance
Internet governance is the development and application by governments, the private sector and civil society, in their respective roles, of shared principles, norms, rules, decision-making procedures and programs that shape the evolution and use of the Internet.
Internet Number Resources
Refers to IPv4 and IPv6 address blocks and Autonomous System (AS) Numbers, which are collectively known as Internet number resources.
Internet Registry
An organization that is responsible for distributing IP address space to its members or customers and for registering those distributions. IRs include: Regional Internet Registries (RIRs), National Internet Registries (NIRs) and Local Internet Registries (LIRs).
IP address – Internet Protocol address
A unique numerical address used to identify a particular piece of hardware connected to the Internet. An IP address serves two principal functions: host or network interface identification and location addressing.
IPv4 – Internet Protocol version 4
A method of identifying IP addresses as 32-bit numbers usually expressed as a “dotted-quad” of four octets. Each octet is expressed as a number between 0 and 255. For example,
IPv4 Exhaustion
The term used to describe the depletion of the pool of available IPv4 address space. The Internet Assigned Numbers Authority’s (IANA) pool of IPv4 address space was deemed exhausted on 3 February 2011 after it delegated its last five /8 address blocks to the five RIRs. See also: IPv6
IPv6 – Internet Protocol version 6
A method of identifying IP numbers as 128-bit numbers in eight 16-bit pieces using hexadecimal values, such as 2001:DB8:8::260:97ff:fe40:efab. IPv6 was introduced in 1999 and has been in use ever since. It greatly expands the amount of IP address space, and allows for 2128, or roughly 340 trillion trillion trillion, unique IP addresses.
ITHI – Internet Technical Health Identifiers
An ICANN initiative to improve the security, stability and resiliency of the Internet’s unique identifier system, by developing metrics to measure the health of this unique identifier system. At the request of ICANN, the Regional Internet Registries (RIRs) are providing input through measurement of the accuracy of its registry data. Accuracy is critical to the reliability of the RIR whois databases, as this data is publicly available.
LACNIC – Latin American and Caribbean Network Information Center
LACNIC is the Internet Addresses Registry for Latin America and Caribbean.
Legacy Resources
A legacy Internet number resource is an IPv4 address or Autonomous System Number (ASN) that was issued by an Internet Registry (InterNIC or its predecessors) prior to the formation of a Regional Internet Registry (RIR) with responsibility for address distribution in the relevant geographic region.
LIR – Local Internet Registry
An Internet Registry (IR) that primarily assigns address space to the users of the network services that it provides. LIRs are generally Internet Service Providers (ISPs) whose customers are primarily end users and possibly other ISPs.
NIR – National Internet Registry
A NIR primarily allocates address space to its members or constituents which are generally LIRs organized at a national level. NIRs mostly exist in the Asia Pacific region.
NRO – Number Resource Organization
The Number Resource Organization (NRO) was established in 2003 as a coordinating body for the world’s five Regional Internet Registries (RIRs). The CEOs of each RIR form the NRO Executive Council (EC). Its main roles are to protect the unallocated number resource pool, to promote and protect the bottom-up policy development process, and to act as a focal point for Internet community input into the RIR system. See also: ASO.  
The CEOs/Directors of the five Regional Internet Registries (RIRs) form the Number Resource Organization Executive Council (NRO EC). The positions of NRO Chair, Vice Chair/Secretary and Treasurer rotate annually. The NRO EC acts by consensus from all five CEOs/Directors.
NRO NC – Number Resource Organization (NRO) Number Council
An elected body of 15 volunteers. As stated in the ICANN ASO MoU, the NRO NC serves as the ASO Address Council (ASO AC). The NRO NC/ASO AC Oversees recommendations on global IP address policy, including the management of policy development activities and appointments to Seats 9 and 10 of the ICANN Board of Directors. Each RIR community selects two people to serve on the NRO NC/ASO AC using its own community-driven processes. Each RIR’s Executive Board also appoints one person from its respective region to serve on the NRO NC/ASO AC. See also: ASO AC, NRO.
PDP – Policy Development Process
The method by which the policies that govern how Internet number resources are distributed by the Regional Internet Registries (RIRs) are developed. Each RIR community develops its own bottom up, open and transparent policy development process (PDP) and anyone can submit a policy proposal. Each RIR facilitates its own PDP. RIRs do not propose, develop, reject or accept policy proposals. See also: GPDP.
PPFT – Policy Proposal Facilitator Team
The PPFT is formed from members of the Address Supporting Organization Address Council (ASO AC).  At the beginning of each term, the ASO AC forms a PPFT consisting of one council member from each of the regions. The PPFT is responsible for monitoring that the correct Global Policy Development (GPDP) procedure has been followed when global policy proposals are proposed by the community (see ASO AC Operating Procedures section 6.3). See also: GPDP.
PTI – Public Technical Identifiers (PTI)
Public Technical Identifiers (PTI) is responsible for the operational aspects of coordinating the Internet’s unique identifiers and maintaining the trust of the community to provide these services in an unbiased, responsible and effective manner. Mainly, PTI is responsible for the operation of the IANA functions: Domain Names, Number Resources and Protocol Parameter Assignments. PTI was incorporated as an affiliate of ICANN in August 2016, and, through contracts and subcontracts with ICANN, began performing the IANA functions in October 2016. From 2002-2016, the IANA functions were performed by ICANN under a contract awarded by the US government’s National Telecommunications and Information Administration (NTIA). See IANA Functions, IANA Oversight Transition.
rDNS – Reverse DNS
A database of information that translates an IP address to a domain or a host name.
Reverse Delegation
See Reverse DNS (rDNS).
RFC – Request for Comment
The IETF’s document series that focuses on concepts, networking, and Internet protocols.
RIPE – Réseaux IP Européens
RIPE is collaborative forum open to all parties interested in wide area IP networks. The objective of RIPE is to ensure the administrative and technical coordination necessary to enable the operation of the Internet within the RIPE NCC service region. Although similar in name, the RIPE NCC and RIPE are separate entities.
The RIPE NCC Regional Internet Registry (RIR) serving countries in Europe, the Middle East, and parts of Central Asia.
RIR – Regional Internet Registry
An organization overseeing the allocation and registration of Internet number resources within a particular region of the world. Resources include IP addresses (IPv4 and IPv6) and Autonomous System Numbers (ASNs). Public Technical Identifiers (PTI) allocates these resources to each RIR. RIRs also maintain public databases of their registration information. There are five RIRs in the world: AFRINIC, APNIC, ARIN, LACNIC, and RIPE NCC. See also: AFRINIC, APNIC, ARIN, LACNIC, RIPE NCC, PTI, IANA.
The root level is the top level of the Domain Name System, a hierarchical tree-like structure that maps domain names to IP addresses. Top-level domains include .com, .org, and country-level names such as .ca and .au.
Root Server
A DNS server pointing to all top-level domains.
Route Origin Authorization (ROA)
A ROA is a digitally signed object that was created using a resource certificate. It provides a means of verifying that an IP address block holder has authorized an AS to originate routes to one or more prefixes within the address block. See also: RPKI.
Routing Registry
A public database of routing policy details, routes, and their aggregates, local topology between Autonomous Systems (AS) and network components, such as routers.
RPKI – Resource Public Key Infrastructure
RPKI is the process of linking a digital “resource certificate” to an Internet number resource using Public Key Infrastructure (PKI) principles. This provides validatable proof that the associated resources are legitimately registered by the signing RIR. Resource certification is based on IETF standards as described in RFC 6481-6493. The primary goal is to make Internet routing more robust and secure.
Schulze Method 
The Schulze Method is the method used by the Address Supporting Organization Address Council (ASO AC)  to count votes during elections, such as the selection of candidates for the ICANN Board Seats 9 and 10. It is a method that selects a single winner using votes that express preferences. The method can also be used to create a sorted list of winners (see ASO AC Operating Procedures section
Transition Mechanisms
Methods of transitioning from IPv4 to IPv6.
A query and response protocol that is widely used for querying databases that store the registered users or assignees of an Internet resource, such as a domain name, an IP address block, or an autonomous system, but is also used for a wider range of other information. The protocol stores and delivers database content in a human-readable format. The RIRs operate WHOIS database.








Last modified on 22/05/2024