Domain Name Basics

Extensible Provisioning Protocol (EPP)a short introduction for newcomers

HistoryThe Extensible Provisioning Protocol (EPP) is a flexible protocol designed for allocating

objects, such as domain name registrations and transfers, within domain name

registries and to provide a robust protocol to communicate between registries and

registrars.

Prior to its introduction, registries had no uniform approach, and many different

proprietary interfaces existed.

11/2000 – the first protocol drafts were published by Scott Hollenbeck.

03/2004 – proposed standard documents (RFCs 3730 - 3734) were published.

05/2007 – draft standard documents (RFCs 4930 - 4934) were published.

08/2009 – IETF granted EPP the status of full standard.

2 | Tobias Sattler, CIO www.united-domains.de

Technology EPP is based on XML – a structured, text-based format and defined in the related

RFCs 3735, 3915, 5730-5734 and 5910.

The underlying network transport is not fixed, although the only currently specified

method is over TCP.

3 | Tobias Sattler, CIO www.united-domains.de

Source: https://www.isoc.org/dotorg/bid/images/xml02.gif - Effective 08/2016

Flow chart This simplified flow chart explains a domain name registration.

4 | Tobias Sattler, CIO www.united-domains.de

Registrant Registrar

looks up andorders a domain

Registry

Checks and controls orderand sends an EPP request

Checks request, updating database,sends EPP confirmationsends confirmation

Status Codes EPP domain status codes, also called domain name status codes, indicate the status

of a domain name registration.

Following the RFCs, there are 23 standardized EPP status codes.

These status codes may be set by a domain name registry: addPeriod, autoRenewPeriod, inactive, ok, pendingCreate, pendingDelete, pendingRenew,

pendingRestore, pendingTransfer, pendingUpdate, redemptionPeriod, renewPeriod,

serverDeleteProhibited, serverHold, serverRenewProhibited, serverTransferProhibited,

serverUpdateProhibited and transferPeriod

These status codes may be set by a domain name registrar: clientDeleteProhibited, clientHold, clientRenewProhibited, clientTransferProhibited,

clientUpdateProhibited

For further information about EPP status codes please see https://icann.org/epp

5 | Tobias Sattler, CIO www.united-domains.de

Extensions EPP is adjustable with extensions to allow registries to adjust it for their need, such

as providing the birthdate, ID number, commercial register number and/or

attachments of the registrant and/or additional contacts.

The IANA lists a number of EPP extensions on their website, but there are a lot more

extensions in use.

(See also http://www.iana.org/assignments/epp-extensions/epp-extensions.xhtml)

One of the most recent used extensions is the new ’Registry Fee Extension for EPP’

by Gavin Brown and Jothan Frakes which allows to set multiple price points for

domain names.

(See also: https://tools.ietf.org/html/draft-ietf-regext-epp-fees-00)

6 | Tobias Sattler, CIO www.united-domains.de

Adoption EPP has been adopted by a number of domain name registries, such as

.ac, .aero, .asia, .at, .be, .biz, .ca, .cat, .ch, .cn, .co, .com, .eu, .fm, .im, .in, .info, .io, .la, .me, .mobi, .mx,

.name, .net, .nl, .nz, .org, .ru, .se, .tel, .travel, .tv, .uk, .us, .za and many more.

The protocol is a must for new gTLDs, such as .berlin, .bayern, .car, .club, .guru, .link, .lol, .online, .rocks, .shop, .vip, .web, .xyz and many more.

For various reasons, there are still some ccTLD registries not supporting EPP, hence

still using proprietary interfaces, such as .ad, .am, .ba, .bg, .cy, .de, .hu, .ie, .md, .mt, .sk, .tk and many more.

7 | Tobias Sattler, CIO www.united-domains.de

Challenges A lot of registries are building their own EPP system instead of buying a solution

and in many cases they are reinventing the wheel.

Some ccTLD domain name registries are not supporting EPP, which makes it very

inconvenient for registrars to work with them.

A couple of registries are relying on EPP extensions and some of them are using

extensions very extensively. Hence implementation and maintaining efforts are

growing. Furthermore the registrant’s user experience isn’t optimal due to the

additional data that needs to be collected during the registration process.

8 | Tobias Sattler, CIO www.united-domains.de

Future From a domain name registrar perspective united-domains is encouraging domain

name registries to support EPP without any extension and over TCP. If any

extension is really inevitable, please check if another registry is already using a

similar one in order to avoid duplicates.

We would also hope that some EPP extensions would be consolidated and

submitted as a RFC instead of proprietary ones. That would help the whole domain

name industry.

9 | Tobias Sattler, CIO www.united-domains.de

Thank you!

Please get in touch if you have any further questions:

https://tobiassattler.com

tobiassattler

10 | Tobias Sattler, CIO www.united-domains.de