Registrars, registries, registrants…
When registering a domain name*), we can choose from a lot of registrars. Simply put, registrars are the middlemen who interact with registries on behalf of registrants. Got that?
Well, the terminology is a bit confusing, so let’s start with some definitions [Abley, 2003].
- “registrant” - the organization or person responsible for a domain;
- “registrars” - the middlemen who interact with registries on behalf of registrants;
- “registry” - the organization which maintains the register and publishes the zone;
- “register” - the data that is maintained by the registry.
For a comprehensive listing of all ICANN-Accredited Registrars, see this overview from ICANN.
The domain registration process
Because there are so many registrars, guidelines and policies are important. In a presentation from Joe Abley (ISC) you will see in detail what’s exactly going on after you hit that submit button and order your favorite domain name.
In his presentation, Joe talks about EPP: the Extensible Provisioning Protocol. This is one of the technical protocols that Registrars will use during the registration of domain names.
EPP defined: EPP is an application layer client-server protocol for the provisioning and management of objects stored in a shared central repository. Specified in XML, the protocol defines generic object management operations and an extensible framework that maps protocol operations to objects.
The original motivation for this protocol was to provide a standard Internet domain name registration protocol for use between domain name registrars and domain name registries. This protocol provides a means of interaction between a registrar’s applications and registry applications. It is expected that this protocol will have additional uses beyond domain name registration.
Current status of EPP (March 2004)
A complete set of EPP documents from the Provisioning Registry Protocol Working Group has now made it to RFC. These RFCs describe the EPP protocol in technical detail. EPP meets and exceeds the requirements for a generic registry registrar protocol as described in RFC 3375: Generic Registry-Registrar Protocol Requirements (Sep 2002).
- RFC 3730: Extensible Provisioning Protocol (EPP)
- RFC 3731: Extensible Provisioning Protocol (EPP) Domain Name Mapping
- RFC 3732: Extensible Provisioning Protocol (EPP) Host Mapping
- RFC 3733: Extensible Provisioning Protocol (EPP) Contact Mapping
- RFC 3734: Extensible Provisioning Protocol (EPP) Transport Over TCP
- RFC 3735: Guidelines for Extending the Extensible Provisioning Protocol (EPP)
In case you’d like to know more about this topic, you will find these resources helpful as well:
*) This article describes the process for registering some of the major generic toplevel domains (gTLD), such as .com, .net, and .org. Terminology and procedures mentioned in the documents are not necessarily the same for ccTLD domain names. And in fact, not even for all gTLDs. Thanks for this remark, Chris!