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<div class="moz-cite-prefix">On 3/11/19 2:17 PM, JORDI PALET
MARTINEZ via AfrIPv6-Discuss wrote:<br>
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<p class="MsoNormal"><span
style="font-size:12.0pt;mso-fareast-language:EN-US"
lang="EN-US">Responding below, in-line, and numbered the
cases.<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:12.0pt;mso-fareast-language:EN-US"
lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span
style="font-size:12.0pt;mso-fareast-language:EN-US"
lang="EN-US">I think I’m right, but happy to
discuss/clarify!<o:p></o:p></span></p>
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<p class="MsoNormal"><span
style="font-size:10.5pt;color:black" lang="EN-US"><br>
Regards,<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span
style="font-size:10.5pt;color:black;mso-fareast-language:EN-US"
lang="EN-US">Jordi<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span
style="font-size:10.5pt;color:black;mso-fareast-language:EN-US"
lang="EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span
style="font-size:12.0pt;mso-fareast-language:EN-US"
lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span
style="font-size:12.0pt;mso-fareast-language:EN-US"
lang="EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal" style="margin-left:35.4pt"><b><span
style="font-size:12.0pt;color:black">De: </span></b><span
style="font-size:12.0pt;color:black">Lee Howard
<a class="moz-txt-link-rfc2396E" href="mailto:lee.howard@retevia.net"><lee.howard@retevia.net></a><br>
<b>Responder a: </b>IPv6 in Africa Discussions
<a class="moz-txt-link-rfc2396E" href="mailto:afripv6-discuss@afrinic.net"><afripv6-discuss@afrinic.net></a><br>
<b>Fecha: </b>lunes, 11 de marzo de 2019, 19:03<br>
<b>Para: </b><a class="moz-txt-link-rfc2396E" href="mailto:afripv6-discuss@afrinic.net"><afripv6-discuss@afrinic.net></a><br>
<b>Asunto: </b>Re: [AfrIPv6-Discuss] AfrIPv6-Discuss
Digest, Vol 149, Issue 1<o:p></o:p></span></p>
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<p class="MsoNormal" style="margin-left:35.4pt"><o:p> </o:p></p>
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<ol start="1" type="1">
<li style="margin-left:17.4pt;mso-list:l0 level1 lfo1"><span
lang="EN-US">If it is an IPv6 flow, it does not use the
CLAT function in the handset. </span>It might use a NAT64
function at the provider edge.<o:p></o:p></li>
</ol>
<p><span style="font-size:12.0pt" lang="EN-US">Let’s say if the
source app is IPv6, using DNS64, it will be an IPv6-only
flow in the operator network and the NAT64 will be used only
if the destination is IPv4-only.</span></p>
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</blockquote>
Yes, the phone will use IPv6, because the name server will only
return a AAAA; the app will never see an IPv4 DNS response.<br>
<blockquote type="cite"
cite="mid:3F6BD401-2C3E-49C2-8E9E-0ACB604A0E2D@consulintel.es">
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<p><span style="font-size:12.0pt" lang="EN-US"><o:p></o:p></span></p>
<ol start="2" type="1">
<li style="margin-left:17.4pt;mso-list:l0 level1 lfo1"><span
lang="EN-US">If it is an IPv4 flow, the handset translates
from IPv4 to IPv6 (the CLAT function). </span>My guess -
and it's only speculation - is that the handset takes a few
milliseconds to do this for each packet. The flow might also
use a NAT64 function at the provider edge.<o:p></o:p></li>
</ol>
<p><span style="font-size:12.0pt" lang="EN-US">If the source app
is IPv4-only, the CLAT will do stateless NAT46 (how this is
done may depend on the implementation). If it is done “full
stateless” I guess is much faster than a NAT44 then a NAT46.</span></p>
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</blockquote>
<p>When would a handset do NAT44? <br>
</p>
<p>In a native dual-stack network, or native IPv4-only network, the
handset never translates. In a 464xlat network, the handset
translates to IPv6 if the app uses IPv4 literals or expects IPv4.
In Apple handsets, this doesn't happen because all apps are
required to support IPv6 (with NAT64).<br>
</p>
<blockquote type="cite"
cite="mid:3F6BD401-2C3E-49C2-8E9E-0ACB604A0E2D@consulintel.es">
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<p><span style="font-size:12.0pt" lang="EN-US"> In this case, it
will always use NAT64, unless we work on this (case for
IPv4-only SmartTVs):<o:p></o:p></span></p>
<p><span style="font-size:12.0pt" lang="EN-US"><a
href="https://datatracker.ietf.org/doc/draft-palet-v6ops-464xlat-opt-cdn-caches/?include_text=1"
moz-do-not-send="true">https://datatracker.ietf.org/doc/draft-palet-v6ops-464xlat-opt-cdn-caches/?include_text=1</a><o:p></o:p></span></p>
<p><span style="font-size:12.0pt" lang="EN-US">If we work on
solving this issue, the NAT64 doesn’t need to be used! And
is not too complex, I think … EAMT already exist for that.</span></p>
</div>
</blockquote>
<p>We should discuss that on v6ops. My initial reaction is that I'm
tired of new transition technologies. Let it go, IPv4 will never
be as good as native connectivity.</p>
<p>I also don't like the fact that rich CDNs already have
preferential placement inside carriers' networks; if they want
better connectivity, they should run IPv6, not expect the ISP to
do translation for them.</p>
<p>Pushing more work onto the handset is the wrong direction. Work
needs to be done on devices with big CPUs and connected power
supplies.<br>
</p>
<p> </p>
<blockquote type="cite"
cite="mid:3F6BD401-2C3E-49C2-8E9E-0ACB604A0E2D@consulintel.es">
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<p><span style="font-size:12.0pt" lang="EN-US"><o:p></o:p></span></p>
<ol start="3" type="1">
<li style="margin-left:17.4pt;mso-list:l0 level1 lfo1"><span
lang="EN-US">If it was an IPv4-only network or dual-stack
network, there's no CLAT, only NAT at the provider edge.<o:p></o:p></span></li>
</ol>
<p><span style="font-size:12.0pt" lang="EN-US">Depends on the
deployment model. It may be only NAT at the CPE, or NAT at
the CPE and CGN, so we have NAT444 …</span></p>
</div>
</blockquote>
Yes, you're right, I was thinking about mobile networks.<br>
<blockquote type="cite"
cite="mid:3F6BD401-2C3E-49C2-8E9E-0ACB604A0E2D@consulintel.es">
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<p><span style="font-size:12.0pt" lang="EN-US"><o:p></o:p></span></p>
<p><span style="font-size:12.0pt" lang="EN-US">But in this case
(3), if the destination is an IPv6-only datacenter (Facebook
is a simple example), you have also NAT446 at the datacenter
… (it may be just NAT46). There are different ways to do
SIIT-DC or other equivalent solutions.</span></p>
</div>
</blockquote>
<p>Yes, also agreed. A residential network with NAT44 on the home
router, CGN44 in the ISP, going to NAT46 at Facebook is NAT4446. <br>
</p>
<p>Lee</p>
<br>
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