<div dir="auto">Yes generally speaking</div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Sat, Mar 9, 2024, 10:43  <<a href="mailto:sburleig.sb@gmail.com">sburleig.sb@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div lang="EN-US" link="blue" vlink="purple" style="word-wrap:break-word"><div class="m_-2940071027920571956WordSection1"><p class="MsoNormal"><span style="font-family:"Aptos",serif">I think we get closer to BSD/POSIX if we use UDP as a model.  The attenuated UDP notion of connect() would work for BP, I think.<u></u><u></u></span></p><p class="MsoNormal"><span style="font-family:"Aptos",serif"><u></u> <u></u></span></p><p class="MsoNormal"><span style="font-family:"Aptos",serif">Scott<u></u><u></u></span></p><p class="MsoNormal"><span style="font-family:"Aptos",serif"><u></u> <u></u></span></p><div><div style="border:none;border-top:solid #e1e1e1 1.0pt;padding:3.0pt 0in 0in 0in"><p class="MsoNormal"><b>From:</b> SIS-DTN <<a href="mailto:sis-dtn-bounces@mailman.ccsds.org" target="_blank" rel="noreferrer">sis-dtn-bounces@mailman.ccsds.org</a>> <b>On Behalf Of </b>Jeremy Mayer via SIS-DTN<br><b>Sent:</b> Saturday, March 9, 2024 12:35 AM<br><b>To:</b> <a href="mailto:vint@google.com" target="_blank" rel="noreferrer">vint@google.com</a>; <a href="mailto:Tomaso.deCola@dlr.de" target="_blank" rel="noreferrer">Tomaso.deCola@dlr.de</a><br><b>Cc:</b> <a href="mailto:sis-dtn@mailman.ccsds.org" target="_blank" rel="noreferrer">sis-dtn@mailman.ccsds.org</a><br><b>Subject:</b> Re: [Sis-dtn] IP networking within DTN-based protocol architectures<u></u><u></u></p></div></div><p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal"><span lang="EN-GB">Hi,<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-GB">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:<u></u><u></u></span></p><ol style="margin-top:0in" start="1" type="A"><li class="m_-2940071027920571956MsoListParagraph" style="margin-left:0in"><span lang="EN-GB">The assumption that relatively low-latency and bidirectional communication is available.<u></u><u></u></span></li><li class="m_-2940071027920571956MsoListParagraph" style="margin-left:0in"><span lang="EN-GB">The layering of stream and message-based semantics.<u></u><u></u></span></li></ol><p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p><p class="MsoNormal"><span lang="EN-GB">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. <u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p><p class="MsoNormal"><span lang="EN-GB">+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.<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p><p class="MsoNormal"><span lang="EN-GB">Thanks,<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-GB">Jeremy<u></u><u></u></span></p><p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p><div style="border:none;border-top:solid #e1e1e1 1.0pt;padding:3.0pt 0in 0in 0in"><p class="MsoNormal"><b>From:</b> SIS-DTN <<a href="mailto:sis-dtn-bounces@mailman.ccsds.org" target="_blank" rel="noreferrer">sis-dtn-bounces@mailman.ccsds.org</a>> <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 <<a href="mailto:Tomaso.deCola@dlr.de" target="_blank" rel="noreferrer">Tomaso.deCola@dlr.de</a>><br><b>Cc:</b> <a href="mailto:sis-dtn@mailman.ccsds.org" target="_blank" rel="noreferrer">sis-dtn@mailman.ccsds.org</a><br><b>Subject:</b> Re: [Sis-dtn] IP networking within DTN-based protocol architectures<u></u><u></u></p></div><p class="MsoNormal"><span lang="DE"><u></u> <u></u></span></p><div><p class="MsoNormal"><span lang="DE">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. <u></u><u></u></span></p><div><p class="MsoNormal"><span lang="DE"><u></u> <u></u></span></p></div><div><p class="MsoNormal"><span lang="DE">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. <u></u><u></u></span></p></div><div><p class="MsoNormal"><span lang="DE"><u></u> <u></u></span></p></div><div><p class="MsoNormal"><span lang="DE">v<u></u><u></u></span></p></div><div><p class="MsoNormal"><span lang="DE"><u></u> <u></u></span></p></div></div><p class="MsoNormal"><span lang="DE"><u></u> <u></u></span></p><div><div><p class="MsoNormal"><span lang="DE">On Fri, Mar 8, 2024 at 4:24 AM Tomaso de Cola via SIS-DTN <<a href="mailto:sis-dtn@mailman.ccsds.org" target="_blank" rel="noreferrer">sis-dtn@mailman.ccsds.org</a>> wrote:<u></u><u></u></span></p></div><blockquote style="border:none;border-left:solid #cccccc 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-top:5.0pt;margin-right:0in;margin-bottom:5.0pt"><div><div><div><p class="MsoNormal"><span lang="DE">Dear All,<u></u><u></u></span></p><p class="MsoNormal"><span lang="DE"> <u></u><u></u></span></p><p class="MsoNormal">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 lang="DE"><u></u><u></u></span></p><p class="MsoNormal">The link to that presentation is as follows:<span lang="DE"><u></u><u></u></span></p><p class="MsoNormal"> <span lang="DE"><u></u><u></u></span></p><p class="MsoNormal"><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" rel="noreferrer">https://cwe.ccsds.org/sis/docs/SIS-DTN/Meeting%20Materials/2023/Fall%202023%20SIS-DTN/Possible%20BOF%20Discussion.pptx?d=w44d31f0b3be649e4bf24ec4ae50479a1</a><span lang="DE"><u></u><u></u></span></p><p class="MsoNormal"> <span lang="DE"><u></u><u></u></span></p><p class="MsoNormal">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 lang="DE"><u></u><u></u></span></p><p class="MsoNormal"> <span lang="DE"><u></u><u></u></span></p><p class="MsoNormal">As discussed yesterday, key points to clarify/agree are:<span lang="DE"><u></u><u></u></span></p><p class="MsoNormal"> <span lang="DE"><u></u><u></u></span></p><ol start="1" type="1"><li class="m_-2940071027920571956m128766250028595583msolistparagraph">Is the proposal sound and meaningful to be addressed?<span lang="DE"><u></u><u></u></span></li><li class="m_-2940071027920571956m128766250028595583msolistparagraph">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 lang="DE"><u></u><u></u></span></li><li class="m_-2940071027920571956m128766250028595583msolistparagraph">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 lang="DE"><u></u><u></u></span></li></ol><p class="MsoNormal"> <span lang="DE"><u></u><u></u></span></p><p class="MsoNormal">Thank you for sharing comments/objections/suggestions.<span lang="DE"><u></u><u></u></span></p><p class="MsoNormal"> <span lang="DE"><u></u><u></u></span></p><p class="MsoNormal">Have a nice weekend,<span lang="DE"><u></u><u></u></span></p><p class="MsoNormal"> <span lang="DE"><u></u><u></u></span></p><p class="MsoNormal">Tomaso<span lang="DE"><u></u><u></u></span></p><p class="MsoNormal"> <span lang="DE"><u></u><u></u></span></p><p class="MsoNormal"><span lang="DE" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:dimgray">————————————————————————</span><span lang="DE" style="font-size:12.0pt;font-family:"Times New Roman",serif"> </span><span lang="DE"><u></u><u></u></span></p><p class="MsoNormal"><b><span lang="DE" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:dimgray">Deutsches Zentrum für Luft- und Raumfahrt</span></b><span lang="DE" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:dimgray"> (DLR)</span><span lang="DE" style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#1f497d"> <br></span><span lang="DE" style="font-size:10.0pt;font-family:"Arial",sans-serif;color:dimgray">German Aerospace Center</span><span lang="DE" style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#1f497d"> <br></span><span lang="DE" 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 lang="DE" style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#1f497d"> </span><span lang="DE"><u></u><u></u></span></p><p class="MsoNormal"><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) 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