<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><br class=""><div><blockquote type="cite" class=""><div class="">Em 28/09/2015, à(s) 16:58:000, Chris Baker <<a href="mailto:cbaker@dyn.com" class="">cbaker@dyn.com</a>> escreveu:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class=""><div class="">Hello,</div><div class=""><br class=""></div><div class="">I was reading the recent ICANN Releases Phase One Registrant Survey on the Domain Name Landscape and saw mention in the metrics section a "% of DNS Service Availability." I was wondering if there was a definition for this measurement available? Possibly some details about how data is collected where it is collected from? ... etc</div><div class=""><br class=""></div><div class="">Please let me know if you have any questions,</div><div class="">Thank you for your time,</div><div class=""> CBaker</div><div class=""><br class=""></div><div class="">Reference:</div><div class=""><div class="">"% of DNS Service Availability ( Present SLA is 100% )" Category - Trust in</div><div class=""><a href="http://newgtlds.icann.org/en/reviews/cct/iag-metrics-final-recs-26sep14-en.pdf" class="">http://newgtlds.icann.org/en/reviews/cct/iag-metrics-final-recs-26sep14-en.pdf</a></div></div><div class=""><br class=""></div></div>
</div></blockquote></div><br class=""><div class=""><a href="http://newgtlds.icann.org/sites/default/files/agreements/agreement-approved-09jan14-en.htm" class="">http://newgtlds.icann.org/sites/default/files/agreements/agreement-approved-09jan14-en.htm</a></div><div class=""><br class=""></div><div class="">Specification 10</div><div class=""><br class=""></div><div class=""><table class="MsoNormalTable" border="1" cellspacing="0" cellpadding="0" style="font-family: Times; widows: 1; border-collapse: collapse; border: none;"><tbody class=""><tr class=""><td width="50" valign="top" style="width: 0.7in; border-style: none solid solid; border-right-color: black; border-bottom-color: black; border-left-color: black; border-right-width: 1pt; border-bottom-width: 1pt; border-left-width: 1pt; padding: 0in 5.4pt;" class=""><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: 'Times New Roman';" class=""><b class=""><span style="font-size: 12pt; font-family: Cambria;" class="">DNS</span></b></div></td><td width="176" valign="top" style="width: 175.5pt; border-style: none solid solid none; border-bottom-color: black; border-bottom-width: 1pt; border-right-color: black; border-right-width: 1pt; padding: 0in 5.4pt;" class=""><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: 'Times New Roman';" class=""><span style="font-size: 12pt; font-family: Cambria;" class="">DNS service availability</span></div></td><td width="253" valign="top" style="width: 252.9pt; border-style: none solid solid none; border-bottom-color: black; border-bottom-width: 1pt; border-right-color: black; border-right-width: 1pt; padding: 0in 5.4pt;" class=""><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: 'Times New Roman'; text-align: center;" class=""><span style="font-size: 12pt; font-family: Cambria;" class="">0 min downtime = 100% availability</span></div></td></tr><tr class=""><td width="50" valign="top" style="width: 0.7in; border-style: none solid solid; border-right-color: black; border-bottom-color: black; border-left-color: black; border-right-width: 1pt; border-bottom-width: 1pt; border-left-width: 1pt; padding: 0in 5.4pt;" class=""><p class="MsoNormal" style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: 'Times New Roman';"><span style="font-size: 12pt; font-family: Cambria;" class=""> </span></p></td><td width="176" valign="top" style="width: 175.5pt; border-style: none solid solid none; border-bottom-color: black; border-bottom-width: 1pt; border-right-color: black; border-right-width: 1pt; padding: 0in 5.4pt;" class=""><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: 'Times New Roman';" class=""><span style="font-size: 12pt; font-family: Cambria;" class="">DNS name server availability</span></div></td><td width="253" valign="top" style="width: 252.9pt; border-style: none solid solid none; border-bottom-color: black; border-bottom-width: 1pt; border-right-color: black; border-right-width: 1pt; padding: 0in 5.4pt;" class=""><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: 'Times New Roman'; text-align: center;" class=""><span style="font-size: 12pt; font-family: Symbol;" class="">£</span><span style="font-size: 12pt; font-family: Cambria;" class=""> 432 min of downtime (</span><span style="font-size: 12pt; font-family: Symbol;" class="">»</span><span style="font-size: 12pt; font-family: Cambria;" class=""> 99%)</span></div></td></tr><tr class=""><td width="50" valign="top" style="width: 0.7in; border-style: none solid solid; border-right-color: black; border-bottom-color: black; border-left-color: black; border-right-width: 1pt; border-bottom-width: 1pt; border-left-width: 1pt; padding: 0in 5.4pt;" class=""><p class="MsoNormal" style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: 'Times New Roman';"><span style="font-size: 12pt; font-family: Cambria;" class=""> </span></p></td><td width="176" valign="top" style="width: 175.5pt; border-style: none solid solid none; border-bottom-color: black; border-bottom-width: 1pt; border-right-color: black; border-right-width: 1pt; padding: 0in 5.4pt;" class=""><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: 'Times New Roman';" class=""><span style="font-size: 12pt; font-family: Cambria;" class="">TCP DNS resolution RTT</span></div></td><td width="253" valign="top" style="width: 252.9pt; border-style: none solid solid none; border-bottom-color: black; border-bottom-width: 1pt; border-right-color: black; border-right-width: 1pt; padding: 0in 5.4pt;" class=""><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: 'Times New Roman'; text-align: center;" class=""><span style="font-size: 12pt; font-family: Symbol;" class="">£</span><span style="font-size: 12pt; font-family: Cambria;" class=""> 1500 ms, for at least 95% of the queries</span></div></td></tr><tr class=""><td width="50" valign="top" style="width: 0.7in; border-style: none solid solid; border-right-color: black; border-bottom-color: black; border-left-color: black; border-right-width: 1pt; border-bottom-width: 1pt; border-left-width: 1pt; padding: 0in 5.4pt;" class=""><p class="MsoNormal" style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: 'Times New Roman';"><span style="font-size: 12pt; font-family: Cambria;" class=""> </span></p></td><td width="176" valign="top" style="width: 175.5pt; border-style: none solid solid none; border-bottom-color: black; border-bottom-width: 1pt; border-right-color: black; border-right-width: 1pt; padding: 0in 5.4pt;" class=""><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: 'Times New Roman';" class=""><span style="font-size: 12pt; font-family: Cambria;" class="">UDP DNS resolution RTT</span></div></td><td width="253" valign="top" style="width: 252.9pt; border-style: none solid solid none; border-bottom-color: black; border-bottom-width: 1pt; border-right-color: black; border-right-width: 1pt; padding: 0in 5.4pt;" class=""><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: 'Times New Roman'; text-align: center;" class=""><span style="font-size: 12pt; font-family: Symbol;" class="">£</span><span style="font-size: 12pt; font-family: Cambria;" class=""> 500 ms, for at least 95% of the queries</span></div></td></tr><tr class=""><td width="50" valign="top" style="width: 0.7in; border-style: none solid solid; border-right-color: black; border-bottom-color: black; border-left-color: black; border-right-width: 1pt; border-bottom-width: 1pt; border-left-width: 1pt; padding: 0in 5.4pt;" class=""><p class="MsoNormal" style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: 'Times New Roman';"><span style="font-size: 12pt; font-family: Cambria;" class=""> </span></p></td><td width="176" valign="top" style="width: 175.5pt; border-style: none solid solid none; border-bottom-color: black; border-bottom-width: 1pt; border-right-color: black; border-right-width: 1pt; padding: 0in 5.4pt;" class=""><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: 'Times New Roman';" class=""><span style="font-size: 12pt; font-family: Cambria;" class="">DNS update time</span></div></td><td width="253" valign="top" style="width: 252.9pt; border-style: none solid solid none; border-bottom-color: black; border-bottom-width: 1pt; border-right-color: black; border-right-width: 1pt; padding: 0in 5.4pt;" class=""><div style="margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: 'Times New Roman'; text-align: center;" class=""><span style="font-size: 12pt; font-family: Symbol;" class="">£</span><span style="font-size: 12pt; font-family: Cambria;" class=""> 60 min, for at least 95% of the probes</span></div></td></tr></tbody></table><div class=""><br class=""></div></div><div class=""><p class="Spec1L2" style="margin: 0in 0in 12pt 0.5in; text-indent: -0.5in; font-size: 11pt; font-family: 'Times New Roman'; widows: 1;"><span style="font-size: 12pt; font-family: Cambria;" class="">3.<span style="font-size: 7pt; font-family: 'Times New Roman';" class=""> </span></span><b class=""><u class=""><span style="font-size: 12pt; font-family: Cambria;" class="">DNS</span></u></b></p><p class="Spec1L3" style="margin: 0in 0in 12pt 1in; text-indent: -0.5in; font-size: 11pt; font-family: 'Times New Roman'; widows: 1;"><a name="_DV_M418" class=""></a><span style="font-size: 12pt; font-family: Cambria;" class="">3.1.<span style="font-size: 7pt; font-family: 'Times New Roman';" class=""> </span></span><b class=""><span style="font-size: 12pt; font-family: Cambria;" class="">DNS service availability</span></b><span style="font-size: 12pt; font-family: Cambria;" class="">. Refers to the ability of the group of listed-as-authoritative name servers of a particular domain name (e.g., a TLD), to answer DNS queries from DNS probes. For the service to be considered available at a particular moment, at least, two of the delegated name servers registered in the DNS must have successful results from “<b class="">DNS tests</b>” to each of their public-DNS registered “<b class="">IP addresses</b>” to which the name server resolves. If 51% or more of the DNS testing probes see the service as unavailable during a given time, the DNS service will be considered unavailable.</span></p><p class="Spec1L3" style="margin: 0in 0in 12pt 1in; text-indent: -0.5in; font-size: 11pt; font-family: 'Times New Roman'; widows: 1;"><a name="_DV_M419" class=""></a><span style="font-size: 12pt; font-family: Cambria;" class="">3.2.<span style="font-size: 7pt; font-family: 'Times New Roman';" class=""> </span></span><b class=""><span style="font-size: 12pt; font-family: Cambria;" class="">DNS name server availability</span></b><span style="font-size: 12pt; font-family: Cambria;" class="">. Refers to the ability of a public-DNS registered “<b class="">IP address</b>” of a particular name server listed as authoritative for a domain name, to answer DNS queries from an Internet user. All the public DNS-registered “<b class="">IP address</b>” of all name servers of the domain name being monitored shall be tested individually. If 51% or more of the DNS testing probes get undefined/unanswered results from “<b class="">DNS tests</b>” to a name server “<b class="">IP address</b>” during a given time, the name server “<b class="">IP address</b>” will be considered unavailable.</span></p><p class="Spec1L3" style="margin: 0in 0in 12pt 1in; text-indent: -0.5in; font-size: 11pt; font-family: 'Times New Roman'; widows: 1;"><a name="_DV_M420" class=""></a><span style="font-size: 12pt; font-family: Cambria;" class="">3.3.<span style="font-size: 7pt; font-family: 'Times New Roman';" class=""> </span></span><b class=""><span style="font-size: 12pt; font-family: Cambria;" class="">UDP DNS resolution RTT</span></b><span style="font-size: 12pt; font-family: Cambria;" class="">. Refers to the <b class="">RTT</b> of the sequence of two packets, the UDP DNS query and the corresponding UDP DNS response. If the <b class="">RTT</b> is 5 times greater than the time specified in the relevant<b class="">SLR</b>, the <b class="">RTT</b> will be considered undefined.</span></p><p class="Spec1L3" style="margin: 0in 0in 12pt 1in; text-indent: -0.5in; font-size: 11pt; font-family: 'Times New Roman'; widows: 1;"><a name="_DV_M421" class=""></a><span style="font-size: 12pt; font-family: Cambria;" class="">3.4.<span style="font-size: 7pt; font-family: 'Times New Roman';" class=""> </span></span><b class=""><span style="font-size: 12pt; font-family: Cambria;" class="">TCP DNS resolution RTT</span></b><span style="font-size: 12pt; font-family: Cambria;" class="">. Refers to the <b class="">RTT</b> of the sequence of packets from the start of the TCP connection to its end, including the reception of the DNS response for only one DNS query. If the <b class="">RTT</b> is 5 times greater than the time specified in the relevant <b class="">SLR</b>, the <b class="">RTT</b> will be considered undefined.</span></p><p class="Spec1L3" style="margin: 0in 0in 12pt 1in; text-indent: -0.5in; font-size: 11pt; font-family: 'Times New Roman'; widows: 1;"><a name="_DV_M422" class=""></a><span style="font-size: 12pt; font-family: Cambria;" class="">3.5.<span style="font-size: 7pt; font-family: 'Times New Roman';" class=""> </span></span><b class=""><span style="font-size: 12pt; font-family: Cambria;" class="">DNS resolution RTT</span></b><span style="font-size: 12pt; font-family: Cambria;" class="">. Refers to either “<b class="">UDP DNS resolution RTT</b>” or “<b class="">TCP DNS resolution RTT</b>”.</span></p><p class="Spec1L3" style="margin: 0in 0in 12pt 1in; text-indent: -0.5in; font-size: 11pt; font-family: 'Times New Roman'; widows: 1;"><a name="_DV_M423" class=""></a><span style="font-size: 12pt; font-family: Cambria;" class="">3.6.<span style="font-size: 7pt; font-family: 'Times New Roman';" class=""> </span></span><b class=""><span style="font-size: 12pt; font-family: Cambria;" class="">DNS update time</span></b><span style="font-size: 12pt; font-family: Cambria;" class="">. Refers to the time measured from the reception of an EPP confirmation to a transform command on a domain name, until the name servers of the parent domain name answer “<b class="">DNS queries</b>” with data consistent with the change made. This only applies for changes to DNS information.</span></p><p class="Spec1L3" style="margin: 0in 0in 12pt 1in; text-indent: -0.5in; font-size: 11pt; font-family: 'Times New Roman'; widows: 1;"><a name="_DV_M424" class=""></a><span style="font-size: 12pt; font-family: Cambria;" class="">3.7.<span style="font-size: 7pt; font-family: 'Times New Roman';" class=""> </span></span><b class=""><span style="font-size: 12pt; font-family: Cambria;" class="">DNS test</span></b><span style="font-size: 12pt; font-family: Cambria;" class="">. Means one non-recursive DNS query sent to a particular “<b class="">IP address</b>” (via UDP or TCP). If DNSSEC is offered in the queried DNS zone, for a query to be considered answered, the signatures must be positively verified against a corresponding DS record published in the parent zone or, if the parent is not signed, against a statically configured Trust Anchor. The answer to the query must contain the corresponding information from the Registry System, otherwise the query will be considered unanswered. A query with a “<b class="">DNS resolution RTT</b>” 5 times higher than the corresponding SLR, will be considered unanswered. The possible results to a DNS test are: a number in milliseconds corresponding to the “<b class="">DNS resolution RTT</b>” or, undefined/unanswered.</span></p><p class="Spec1L3" style="margin: 0in 0in 12pt 1in; text-indent: -0.5in; font-size: 11pt; font-family: 'Times New Roman'; widows: 1;"><a name="_DV_M425" class=""></a><span style="font-size: 12pt; font-family: Cambria;" class="">3.8.<span style="font-size: 7pt; font-family: 'Times New Roman';" class=""> </span></span><b class=""><span style="font-size: 12pt; font-family: Cambria;" class="">Measuring DNS parameters</span></b><span style="font-size: 12pt; font-family: Cambria;" class="">. Every minute, every DNS probe will make an UDP or TCP “<b class="">DNS test</b>” to each of the public-DNS registered “<b class="">IP addresses</b>” of the name servers of the domain name being monitored. If a “<b class="">DNS test</b>” result is undefined/unanswered, the tested IP will be considered unavailable from that probe until it is time to make a new test.</span></p><p class="Spec1L3" style="margin: 0in 0in 12pt 1in; text-indent: -0.5in; font-size: 11pt; font-family: 'Times New Roman'; widows: 1;"><a name="_DV_M426" class=""></a><span style="font-size: 12pt; font-family: Cambria;" class="">3.9.<span style="font-size: 7pt; font-family: 'Times New Roman';" class=""> </span></span><b class=""><span style="font-size: 12pt; font-family: Cambria;" class="">Collating the results from DNS probes</span></b><span style="font-size: 12pt; font-family: Cambria;" class="">. The minimum number of active testing probes to consider a measurement valid is 20 at any given measurement period, otherwise the measurements will be discarded and will be considered inconclusive; during this situation no fault will be flagged against the SLRs.</span></p><p class="Spec1L3" style="margin: 0in 0in 12pt 1in; text-indent: -0.5in; font-size: 11pt; font-family: 'Times New Roman'; widows: 1;"><a name="_DV_M427" class=""></a><span style="font-size: 12pt; font-family: Cambria;" class="">3.10.<span style="font-size: 7pt; font-family: 'Times New Roman';" class=""> </span></span><b class=""><span style="font-size: 12pt; font-family: Cambria;" class="">Distribution of UDP and TCP queries</span></b><span style="font-size: 12pt; font-family: Cambria;" class="">. DNS probes will send UDP or TCP “<b class="">DNS test</b>” approximating the distribution of these queries.</span></p><p class="Spec1L3" style="margin: 0in 0in 12pt 1in; text-indent: -0.5in; font-size: 11pt; font-family: 'Times New Roman'; widows: 1;"><a name="_DV_M428" class=""></a><span style="font-size: 12pt; font-family: Cambria;" class="">3.11.<span style="font-size: 7pt; font-family: 'Times New Roman';" class=""> </span></span><b class=""><span style="font-size: 12pt; font-family: Cambria;" class="">Placement of DNS probes</span></b><span style="font-size: 12pt; font-family: Cambria;" class="">. Probes for measuring DNS parameters shall be placed as near as possible to the DNS resolvers on the networks with the most users across the different geographic regions; care shall be taken not to deploy probes behind high propagation-delay links, such as satellite links.</span></p></div><div class=""><span style="font-size: 12pt; font-family: Cambria;" class=""><br class=""></span></div><div class=""><span style="font-size: 12pt; font-family: Cambria;" class=""><br class=""></span></div><div class=""><span style="font-size: 12pt; font-family: Cambria;" class=""><br class=""></span></div></body></html>