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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple style='word-wrap:break-word'><div class=WordSection1><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.<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Aptos",serif'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-family:"Aptos",serif'>Scott<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Aptos",serif'><o:p> </o:p></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 <sis-dtn-bounces@mailman.ccsds.org> <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> vint@google.com; 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></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span lang=EN-GB>Hi,<o:p></o:p></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:<o:p></o:p></span></p><ol style='margin-top:0in' start=1 type=A><li class=MsoListParagraph style='margin-left:0in;mso-list:l0 level1 lfo3'><span lang=EN-GB>The assumption that relatively low-latency and bidirectional communication is available.<o:p></o:p></span></li><li class=MsoListParagraph style='margin-left:0in;mso-list:l0 level1 lfo3'><span lang=EN-GB>The layering of stream and message-based semantics.<o:p></o:p></span></li></ol><p class=MsoNormal><span lang=EN-GB><o:p> </o:p></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. <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB><o:p> </o:p></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.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-GB>Thanks,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB>Jeremy<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB><o:p> </o:p></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">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">Tomaso.deCola@dlr.de</a>><br><b>Cc:</b> <a href="mailto:sis-dtn@mailman.ccsds.org">sis-dtn@mailman.ccsds.org</a><br><b>Subject:</b> Re: [Sis-dtn] IP networking within DTN-based protocol architectures<o:p></o:p></p></div><p class=MsoNormal><span lang=DE><o:p> </o:p></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. <o:p></o:p></span></p><div><p class=MsoNormal><span lang=DE><o:p> </o:p></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. <o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=DE><o:p> </o:p></span></p></div><div><p class=MsoNormal><span lang=DE>v<o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=DE><o:p> </o:p></span></p></div></div><p class=MsoNormal><span lang=DE><o:p> </o:p></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">sis-dtn@mailman.ccsds.org</a>> wrote:<o:p></o:p></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 style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=DE>Dear All,<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=DE> <o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>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><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>The link to that presentation is as follows:<span lang=DE><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <span lang=DE><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><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 lang=DE><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <span lang=DE><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>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><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <span lang=DE><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>As discussed yesterday, key points to clarify/agree are:<span lang=DE><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <span lang=DE><o:p></o:p></span></p><ol start=1 type=1><li class=m128766250028595583msolistparagraph style='mso-list:l1 level1 lfo6'>Is the proposal sound and meaningful to be addressed?<span lang=DE><o:p></o:p></span></li><li class=m128766250028595583msolistparagraph style='mso-list:l1 level1 lfo6'>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><o:p></o:p></span></li><li class=m128766250028595583msolistparagraph style='mso-list:l1 level1 lfo6'>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><o:p></o:p></span></li></ol><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <span lang=DE><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Thank you for sharing comments/objections/suggestions.<span lang=DE><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <span lang=DE><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Have a nice weekend,<span lang=DE><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <span lang=DE><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Tomaso<span lang=DE><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <span lang=DE><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><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><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><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><o:p></o:p></span></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 lang=DE 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 lang=DE style='font-size:10.0pt;font-family:"Arial",sans-serif;color:#1F497D'> </span><span 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 lang=DE style='color:#1F497D'> <br></span><span 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 style='color:#1F497D'> </span><span lang=DE><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=DE> <o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=DE> <o:p></o:p></span></p></div></div><p class=MsoNormal><span lang=DE>_______________________________________________<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></span></p></div></blockquote></div><p class=MsoNormal><span lang=DE><br clear=all><o:p></o:p></span></p><div><p class=MsoNormal><span lang=DE><o:p> </o:p></span></p></div><p class=MsoNormal><span class=gmailsignatureprefix><span lang=DE>-- </span></span><span lang=DE><o:p></o:p></span></p><div><div><div><p class=MsoNormal><span lang=DE>Please send any postal/overnight deliveries to:<o:p></o:p></span></p></div><div><div><p class=MsoNormal><span lang=DE>Vint Cerf<o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=DE>Google, LLC<o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=DE>1900 Reston Metro Plaza, 16th Floor<o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=DE>Reston, VA 20190<o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=DE>+1 (571) 213 1346<o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=DE><o:p> </o:p></span></p></div></div><div><p class=MsoNormal><span lang=DE><o:p> </o:p></span></p></div><div><p class=MsoNormal><span lang=DE>until further notice<o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=DE><o:p> </o:p></span></p></div><div><p class=MsoNormal><span lang=DE><o:p> </o:p></span></p></div><div><p class=MsoNormal><span lang=DE><o:p> </o:p></span></p></div></div></div></div></body></html>