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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>Marc, FWIW, I agree about deprecating LTP security and I am likewise skeptical that adding more timers is a good idea; that sounds like a way to work around a design element that hasn’t been thought through completely.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Scott<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></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>Sanchez Net, Marc (US 332H) via SIS-DTN<br><b>Sent:</b> Tuesday, May 16, 2023 7:05 PM<br><b>To:</b> Dr. Keith L Scott via SIS-DTN <sis-dtn@mailman.ccsds.org><br><b>Cc:</b> Torgerson, J. Leigh (US 332C) <jordan.l.torgerson@jpl.nasa.gov><br><b>Subject:</b> [Sis-dtn] New version of LTP Corrigendum<o:p></o:p></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal><span style='color:black'>All,<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='color:black'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='color:black'>Please find attached a new version of the LTP corrigendum with some modifications including:<o:p></o:p></span></p></div><div><ul type=disc><li class=MsoNormal style='color:black;mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;mso-list:l0 level1 lfo1'>Comparison between LTP and "the new protocol" has been reduced. This in part motivated by the fact that we have demonstrated ~4 Gbps rates with ION's LTP implementation, which is more than sufficient for deep space links (e.g., even in future trunk lines between Earth and Mars, data rates of 4 Gbps are never exceeded).<o:p></o:p></li><li class=MsoNormal style='color:black;mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;mso-list:l0 level1 lfo1'>I have added two possible additions to the technical corrigendum based on work done by Brian and people at GRC. They are all optional (MAY) statements and I believe can be implemented without additional managed parameters (and timers).<o:p></o:p></li><li class=MsoNormal style='color:black;mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;mso-list:l0 level1 lfo1'>Brian has commented on two additional issues (see <a href="https://github.com/nasa/HDTN/issues/22" title="https://github.com/nasa/HDTN/issues/22">here</a> and <a href="https://github.com/nasa/HDTN/issues/24" title="https://github.com/nasa/HDTN/issues/24">here</a>), but those seem to require additional timers that would need to be managed, so I am unconvinced it is worth the extra complexity. Brian, please correct me if I am wrong.<o:p></o:p></li></ul><div><p class=MsoNormal><span style='color:black'>Finally, I think the note at the beginning of Section 3.9 of the current CCSDS LTP spec should be modified to explicitly state that LTP security should not be used and, instead, implementers should rely on security mechanisms provided by other parts of the CCSDS protocol stack, be it SDLS or BPSec. Thoughts on this point? <o:p></o:p></span></p></div><div><p class=MsoNormal><span style='color:black'><o:p> </o:p></span></p></div><div><div><div style='margin-top:12.0pt;margin-bottom:12.0pt;min-width: 424px' id="LPBorder_GTaHR0cHM6Ly9naXRodWIuY29tL25hc2EvSERUTi9pc3N1ZXMvMjQ."><table class=MsoNormalTable border=1 cellpadding=0 width="100%" style='width:100.0%;border:solid #C8C8C8 1.0pt'><tr><td valign=top style='border:none;padding:9.0pt 27.0pt 9.0pt 9.0pt'><div style='margin-right:9.0pt;overflow:hidden' id=LPImageContainer765850><p class=MsoNormal><a href="https://github.com/nasa/HDTN/issues/24" target="_blank"><span style='text-decoration:none'><img border=0 width=240 height=120 style='width:2.5in;height:1.25in' id="_x0000_i1026" src="https://opengraph.githubassets.com/20650d8341084e048ce0b347834a0c8d441c40acab81b1ef4c075e8770078d33/nasa/HDTN/issues/24"></span></a><o:p></o:p></p></div></td><td width="100%" valign=top style='width:100.0%;border:none;padding:9.0pt 27.0pt 9.0pt 9.0pt'><div style='margin-right:6.0pt;margin-bottom:9.0pt' id=LPTitle765850><p class=MsoNormal><span style='font-size:16.0pt;font-family:"Segoe UI Light",sans-serif'><a href="https://github.com/nasa/HDTN/issues/24" target="_blank"><span style='text-decoration:none'>Defer data retransmission with out-of-order report segments · Issue #24 · nasa/HDTN</span></a><o:p></o:p></span></p></div><div style='margin-right:6.0pt;margin-bottom:9.0pt;max-height: 100px;overflow:hidden' id=LPDescription765850><p class=MsoNormal><span style='font-size:10.5pt;font-family:"Segoe UI",sans-serif;color:#666666'>When the network is causing out-of-order segment reception it is possible that one or more synchronous reception reports are received either out-of-order or within a short time window, possibly fol...<o:p></o:p></span></p></div><div id=LPMetadata765850><p class=MsoNormal><span style='font-size:10.5pt;font-family:"Segoe UI",sans-serif;color:#A6A6A6'>github.com<o:p></o:p></span></p></div></td></tr></table></div></div><table class=MsoNormalTable border=1 cellpadding=0 width="100%" style='width:100.0%;border:solid #C8C8C8 1.0pt'><tr><td valign=top style='border:none;padding:9.0pt 27.0pt 9.0pt 9.0pt'><div style='margin-right:9.0pt;overflow:hidden' id=LPImageContainer694819><p class=MsoNormal><a href="https://github.com/nasa/HDTN/issues/22" target="_blank"><span style='text-decoration:none'><img border=0 width=240 height=120 style='width:2.5in;height:1.25in' id="_x0000_i1025" src="https://opengraph.githubassets.com/557790465f865a493213b66289d08ffd17c4b98d48ae91ec6ef62866fa1ceac9/nasa/HDTN/issues/22"></span></a><o:p></o:p></p></div></td><td width="100%" valign=top style='width:100.0%;border:none;padding:9.0pt 27.0pt 9.0pt 9.0pt'><div style='margin-right:6.0pt;margin-bottom:9.0pt' id=LPTitle694819><p class=MsoNormal><span style='font-size:16.0pt;font-family:"Segoe UI Light",sans-serif'><a href="https://github.com/nasa/HDTN/issues/22" target="_blank"><span style='text-decoration:none'>Defer synchronous reception report with out-of-order data segments · Issue #22 · nasa/HDTN</span></a><o:p></o:p></span></p></div><div style='margin-right:6.0pt;margin-bottom:9.0pt;max-height: 100px;overflow:hidden' id=LPDescription694819><p class=MsoNormal><span style='font-size:10.5pt;font-family:"Segoe UI",sans-serif;color:#666666'>When red part data is segmented and delivered to the receiving engine out-of-order, the checkpoint(s) and EORP can be received before the earlier-in-block data segments. If a synchronous report is ...<o:p></o:p></span></p></div><div id=LPMetadata694819><p class=MsoNormal><span style='font-size:10.5pt;font-family:"Segoe UI",sans-serif;color:#A6A6A6'>github.com<o:p></o:p></span></p></div></td></tr></table></div><div><p class=MsoNormal><span style='color:black'><o:p> </o:p></span></p></div></div><div><div><p class=MsoNormal><span style='color:black'>Thanks,<o:p></o:p></span></p></div><div id=Signature><div><p class=MsoNormal>-----------------------------------------------------------------------------------------------------------------------<o:p></o:p></p><p class=MsoNormal>Marc Sanchez Net (332H)<o:p></o:p></p><p class=MsoNormal><span style='font-size:10.0pt;color:gray'>Telecommunications Engineer</span><o:p></o:p></p><p class=MsoNormal style='background:white'><span style='font-size:10.0pt;color:gray'>Jet Propulsion Laboratory</span><o:p></o:p></p><p class=MsoNormal style='background:white'><span style='font-size:10.0pt;color:gray'>Cell:</span><span style='font-size:10.0pt;font-family:"Arial",sans-serif;color:#222222'> </span><span style='font-size:10.0pt;font-family:"Arial",sans-serif;color:black'><a href="mailto:(617)%20953-7977">(617) 953-7977</a></span><span style='font-size:10.0pt;font-family:"Arial",sans-serif;color:#0070C0'> </span><span style='font-size:10.0pt;color:gray'>|</span><span style='font-size:10.0pt;font-family:"Arial",sans-serif;color:#0070C0'> </span><span style='font-size:10.0pt;color:gray'>Email:</span><span style='font-size:10.0pt;font-family:"Arial",sans-serif;color:#222222'> </span><span style='color:black'><a href="mailto:marc.sanchez.net@jpl.nasa.gov"><span style='font-size:10.0pt;font-family:"Arial",sans-serif'>marc.sanchez.net@jpl.nasa.gov</span></a></span><o:p></o:p></p><p class=MsoNormal>-----------------------------------------------------------------------------------------------------------------------<o:p></o:p></p><p class=MsoNormal> <o:p></o:p></p></div></div></div></div></body></html>