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<p class="MsoNormal"><span lang="EN-GB">Directed Unreliable/Reliable Protocol, DURP?<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
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<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> Wednesday, May 17, 2023 4:35 PM<br>
<b>To:</b> marc.sanchez.net@jpl.nasa.gov; sis-dtn@mailman.ccsds.org<br>
<b>Cc:</b> jordan.l.torgerson@jpl.nasa.gov<br>
<b>Subject:</b> Re: [Sis-dtn] New version of LTP Corrigendum<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span lang="EN-GB">:D :D Oh god, the naming things party begins. We definitely need to have a name discussion at some point, but after my vacation
</span><span lang="EN-GB" style="font-family:Wingdings">J</span><span lang="EN-GB"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
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<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>Sanchez Net, Marc (US 332H) via SIS-DTN<br>
<b>Sent:</b> Wednesday, May 17, 2023 4:11 AM<br>
<b>To:</b> Dr. Keith L Scott via SIS-DTN <<a href="mailto:sis-dtn@mailman.ccsds.org">sis-dtn@mailman.ccsds.org</a>><br>
<b>Cc:</b> Torgerson, J. Leigh (US 332C) <<a href="mailto:jordan.l.torgerson@jpl.nasa.gov">jordan.l.torgerson@jpl.nasa.gov</a>><br>
<b>Subject:</b> Re: [Sis-dtn] New version of LTP Corrigendum<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 style="color:black">Apologies for the two-part email. <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="color:black">Leigh proposes that we call "the new protocol" the "Simplified Link Reliability Protocol" (SLRP), which could be simply pronounced "SLRP" or even better "slurp". Just sharing in case people like it.<o:p></o:p></span></p>
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<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>
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<p class="MsoNormal"><b><span style="color:black">From:</span></b><span style="color:black"> Sanchez Net, Marc (US 332H)<br>
<b>Sent:</b> Tuesday, May 16, 2023 7:05 PM<br>
<b>To:</b> Dr. Keith L Scott via SIS-DTN <<a href="mailto:sis-dtn@mailman.ccsds.org">sis-dtn@mailman.ccsds.org</a>><br>
<b>Cc:</b> Torgerson, J. Leigh (US 332C) <<a href="mailto:jordan.l.torgerson@jpl.nasa.gov">jordan.l.torgerson@jpl.nasa.gov</a>>; Gao, Jay L (US 332C) <<a href="mailto:jay.l.gao@jpl.nasa.gov">jay.l.gao@jpl.nasa.gov</a>><br>
<b>Subject:</b> New version of LTP Corrigendum</span> <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 style="color:black">All,<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="color:black"><o:p> </o:p></span></p>
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<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>
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<li class="MsoNormal" style="color:black;mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;mso-list:l1 level1 lfo3">
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:l1 level1 lfo3">
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:l1 level1 lfo3">
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>
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<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>
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<p class="MsoNormal"><span style="color:black"><o:p> </o:p></span></p>
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<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_i1027" src="https://opengraph.githubassets.com/20650d8341084e048ce0b347834a0c8d441c40acab81b1ef4c075e8770078d33/nasa/HDTN/issues/24"></span></a><o:p></o:p></p>
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<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>
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<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>
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<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>
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<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_i1026" src="https://opengraph.githubassets.com/557790465f865a493213b66289d08ffd17c4b98d48ae91ec6ef62866fa1ceac9/nasa/HDTN/issues/22"></span></a><o:p></o:p></p>
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<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>
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<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>
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<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>
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<p class="MsoNormal"><span style="color:black">Thanks,<o:p></o:p></span></p>
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<p class="xmsonormal">-----------------------------------------------------------------------------------------------------------------------<o:p></o:p></p>
<p class="xmsonormal">Marc Sanchez Net (332H)<o:p></o:p></p>
<p class="xmsonormal"><span style="font-size:10.0pt;color:gray">Telecommunications Engineer</span><o:p></o:p></p>
<p class="xmsonormal" style="background:white"><span style="font-size:10.0pt;color:gray">Jet Propulsion Laboratory</span><o:p></o:p></p>
<p class="xmsonormal" 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="xmsonormal">-----------------------------------------------------------------------------------------------------------------------<o:p></o:p></p>
<p class="xmsonormal"> <o:p></o:p></p>
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