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Building Towards a Comprehensive Registry Failover Plan

Executive Summary

The 2006-2007 ICANN Operating Plan ( describes the series of projects and deliverables based on the ICANN Strategic Plan ( According to the Operating Plan, ICANN is to “establish a comprehensive plan to be followed in the event of financial, technical or business failure of a registry operator, including full compliance with data escrow requirements and recovery testing” (see Section 1.1.2).

This report is being prepared as part of the registry failover project to provide guidance to ICANN and the Internet community in the event of a registry failure. This is not intended to be a policy document. The registry failover project poses a complex set of issues that involve ICANN’s mission in both ensuring DNS stability and promoting competition. Following the 29th ICANN International Public Meeting in San Juan, Puerto Rico, ICANN will synthesize a best practices document describing registry failover mechanisms. These mechanisms will also provide guidance or be incorporated into ICANN’s new gTLD process potentially as a best practices contractual requirement.

ICANN has conducted a review of the critical functions of a registry, examined transition of a registry from one operator to another, and examined potential failure scenarios. This report finds that the identification of critical functions, along with establishment of best practices by registries will assist ICANN in the event that a registry failure occurs. ICANN has identified a number of scenarios that require further examination and discussion before a registry failover plan can be adopted. This report provides the elements of the registry failover plan and initial recommendations based on current registry practices. These elements include best efforts at geographic diversity of name servers, the creation and testing of registry contingency plans, the establishment of a clear communications plan and identification of a failure as a temporary or long-term condition.

Next Steps

In order to provide guidance to the development of the comprehensive registry failover plan, ICANN is seeking input from all interested stakeholders on the issues described in this report. The scenarios described in this report are intended to serve as examples that will help inform and guide failover plan development. This report will also be discussed in a public forum session during the 29th ICANN International Public Meeting in San Juan, Puerto Rico (details to be announced when the meeting agenda is posted). Comments on this report may be submitted to through 28 June 2007 23:59 UTC and may be viewed at In addition, the report will also be posted on the ICANN blog to provide an additional venue for comments and discussion on this topic.

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Internationalized Domain Name ,IDN,"IDNs are domain names that include characters used in the local representation of languages that are not written with the twenty-six letters of the basic Latin alphabet ""a-z"". An IDN can contain Latin letters with diacritical marks, as required by many European languages, or may consist of characters from non-Latin scripts such as Arabic or Chinese. Many languages also use other types of digits than the European ""0-9"". The basic Latin alphabet together with the European-Arabic digits are, for the purpose of domain names, termed ""ASCII characters"" (ASCII = American Standard Code for Information Interchange). These are also included in the broader range of ""Unicode characters"" that provides the basis for IDNs. The ""hostname rule"" requires that all domain names of the type under consideration here are stored in the DNS using only the ASCII characters listed above, with the one further addition of the hyphen ""-"". The Unicode form of an IDN therefore requires special encoding before it is entered into the DNS. The following terminology is used when distinguishing between these forms: A domain name consists of a series of ""labels"" (separated by ""dots""). The ASCII form of an IDN label is termed an ""A-label"". All operations defined in the DNS protocol use A-labels exclusively. The Unicode form, which a user expects to be displayed, is termed a ""U-label"". The difference may be illustrated with the Hindi word for ""test"" — परीका — appearing here as a U-label would (in the Devanagari script). A special form of ""ASCII compatible encoding"" (abbreviated ACE) is applied to this to produce the corresponding A-label: xn--11b5bs1di. A domain name that only includes ASCII letters, digits, and hyphens is termed an ""LDH label"". Although the definitions of A-labels and LDH-labels overlap, a name consisting exclusively of LDH labels, such as"""" is not an IDN."