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<p class="MsoNormal"><span lang="EN-GB" style="mso-fareast-language:EN-US">Hi,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="mso-fareast-language:EN-US">I’m tempted to agree. I’ve seen limited utility in IP->BP encap, as (other than some unidirectional UDP-based applications), the assumptions made in IP networks (especially TCP) do not
scale well to DTN environments. The two largest issues I see are:<o:p></o:p></span></p>
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<li class="MsoListParagraph" style="margin-left:0cm;mso-list:l0 level1 lfo2"><span lang="EN-GB" style="mso-fareast-language:EN-US">The assumption that relatively low-latency and bidirectional communication is available.<o:p></o:p></span></li><li class="MsoListParagraph" style="margin-left:0cm;mso-list:l0 level1 lfo2"><span lang="EN-GB" style="mso-fareast-language:EN-US">The layering of stream and message-based semantics.<o:p></o:p></span></li></ol>
<p class="MsoNormal"><span lang="EN-GB" style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="mso-fareast-language:EN-US">Almost every TCP-ish application which I’ve seen run over BP winds up with exceptionally low performance, unless some sort of PEP is integrated, which adds complexity, failure points,
and fragility. <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="mso-fareast-language:EN-US">+1 for the notion of a standard API though, with the additional caveat that we should standardize nomenclature across implementations. We could likely reuse about 80% of the BSD/POSIX
interface for BP, with the notable exception of connect.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="mso-fareast-language:EN-US">Thanks,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="mso-fareast-language:EN-US">Jeremy<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span lang="EN-US">From:</span></b><span lang="EN-US"> SIS-DTN <sis-dtn-bounces@mailman.ccsds.org>
<b>On Behalf Of </b>Vint Cerf via SIS-DTN<br>
<b>Sent:</b> Freitag, 8. März 2024 12:31<br>
<b>To:</b> de Cola, Tomaso <Tomaso.deCola@dlr.de><br>
<b>Cc:</b> sis-dtn@mailman.ccsds.org<br>
<b>Subject:</b> Re: [Sis-dtn] IP networking within DTN-based protocol architectures<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">The more I think about this, the less I like trying to manage off-Earth IP networks remotely. I think I would much rather see native applications running over BP. In any case we need to develop standard APIs for BP, such as the Sockets
interface for Linux/Unix/Posix. <o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">We do need to figure out how IP-based and BP-based applications interwork. What do Domain Names mean in the BP context for example. <o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">v<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">On Fri, Mar 8, 2024 at 4:24 AM Tomaso de Cola via SIS-DTN <<a href="mailto:sis-dtn@mailman.ccsds.org">sis-dtn@mailman.ccsds.org</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Dear All,<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="EN-US">as mentioned yesterday during our DTN weekly, during the past Fall meeting a presentation was given by University of Nanjing with the support of Chinese agency
about IP-networking within DTN-based protocol stacks, especially for planetary network segments (i.e. what is often referred to as IP-islands).
</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="EN-US">The link to that presentation is as follows:</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="EN-US"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="EN-US"><a href="https://cwe.ccsds.org/sis/docs/SIS-DTN/Meeting%20Materials/2023/Fall%202023%20SIS-DTN/Possible%20BOF%20Discussion.pptx?d=w44d31f0b3be649e4bf24ec4ae50479a1" target="_blank">https://cwe.ccsds.org/sis/docs/SIS-DTN/Meeting%20Materials/2023/Fall%202023%20SIS-DTN/Possible%20BOF%20Discussion.pptx?d=w44d31f0b3be649e4bf24ec4ae50479a1</a></span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="EN-US"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="EN-US">The proposal made there was for a BOF (i.e. towards a WG formation), which I see however too premature. On the contrary, I’d be more in favour for a SIG (Special
Interest Group), happening outside the DTN WG.</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="EN-US"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="EN-US">As discussed yesterday, key points to clarify/agree are:</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="EN-US"> </span><o:p></o:p></p>
<ol start="1" type="1">
<li class="m128766250028595583msolistparagraph" style="mso-list:l1 level1 lfo1"><span lang="EN-US">Is the proposal sound and meaningful to be addressed?</span><o:p></o:p></li><li class="m128766250028595583msolistparagraph" style="mso-list:l1 level1 lfo1"><span lang="EN-US">Is appropriate for the SIS area or should be better addressed at architectural level in SEA (maybe it can be even a cross-area initiative)?</span><o:p></o:p></li><li class="m128766250028595583msolistparagraph" style="mso-list:l1 level1 lfo1"><span lang="EN-US">In the case of SIS, is there significant support to start this? In other words, which agencies have interest in contributing to this activity?</span><o:p></o:p></li></ol>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="EN-US"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="EN-US">Thank you for sharing comments/objections/suggestions.</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="EN-US"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="EN-US">Have a nice weekend,</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="EN-US"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="EN-US">Tomaso</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span lang="EN-US"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:dimgray">————————————————————————</span><span style="font-size:12.0pt;font-family:"Times New Roman",serif">
</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><b><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:dimgray">Deutsches Zentrum für Luft- und Raumfahrt</span></b><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:dimgray">
(DLR)</span><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#1F497D">
<br>
</span><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:dimgray">German Aerospace Center</span><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#1F497D">
<br>
</span><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:dimgray">Institute of Communications and Navigation | Satellite Networks | Oberpfaffenhofen | 82234 Wessling | Germany</span><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#1F497D">
</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><b><span lang="IT" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:dimgray">Tomaso de Cola, Ph.D.</span></b><span lang="IT" style="color:#1F497D"> |
</span><b><span lang="IT" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:dimgray">Integrated Satellite Systems (INS) Team Leader<br>
</span></b><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:dimgray">Telefon
<a href="tel:+49%208153%20282156" target="_blank">+49 8153 28-2156</a> | Telefax
<a href="tel:+49%208153%20282844" target="_blank">+49 8153 28-2844</a> |</span><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#1F497D">
</span><span lang="EN-US" style="color:#1F497D"><a href="mailto:sandro.scalise@dlr.de" target="_blank"><span lang="DE" style="font-size:10.0pt;font-family:"Arial",sans-serif">tomaso.decola@dlr.de</span></a></span><span style="color:#1F497D">
<br>
</span><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#1F497D"><a href="http://www.dlr.de/kn/institut/abteilungen/san" target="_blank"><span lang="DE">http://www.dlr.de/kn/institut/abteilungen/san</span></a></span><span lang="EN-US" style="color:#1F497D">
</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
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<p class="MsoNormal">_______________________________________________<br>
SIS-DTN mailing list<br>
<a href="mailto:SIS-DTN@mailman.ccsds.org" target="_blank">SIS-DTN@mailman.ccsds.org</a><br>
<a href="https://mailman.ccsds.org/cgi-bin/mailman/listinfo/sis-dtn" target="_blank">https://mailman.ccsds.org/cgi-bin/mailman/listinfo/sis-dtn</a><o:p></o:p></p>
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<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><span class="gmailsignatureprefix">-- </span><o:p></o:p></p>
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<p class="MsoNormal">Please send any postal/overnight deliveries to:<o:p></o:p></p>
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<p class="MsoNormal">Vint Cerf<o:p></o:p></p>
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<p class="MsoNormal">Google, LLC<o:p></o:p></p>
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<p class="MsoNormal">1900 Reston Metro Plaza, 16th Floor<o:p></o:p></p>
</div>
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<p class="MsoNormal">Reston, VA 20190<o:p></o:p></p>
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<div>
<p class="MsoNormal">+1 (571) 213 1346<o:p></o:p></p>
</div>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">until further notice<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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