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<p class="MsoNormal"><span style="font-size:11.0pt;mso-fareast-language:EN-US">Hi All,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-fareast-language:EN-US">Concerning the point on the retransmission cycle limit, this is first appearing on RFC 5326 at the end of section 6.2.2 (beginning of page 34) and copied here below for your convenience:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<pre>There may be other implementation-specific limits that may cause an<o:p></o:p></pre>
<pre> LTP implementation to initiate session-cancellation procedures. One<o:p></o:p></pre>
<pre> such limit is the maximum number of retransmission-cycles seen. A<o:p></o:p></pre>
<pre> retransmission cycle at the LTP Sender comprises the two related<o:p></o:p></pre>
<pre> events: the transmission of all outstanding CP segments from the<o:p></o:p></pre>
<pre> sender, and the reception of all RS segments issued from the receiver<o:p></o:p></pre>
<pre> in response to those CP segments. A similar definition would apply<o:p></o:p></pre>
<pre> at the LTP Receiver but relate to the reception of the CP segments<o:p></o:p></pre>
<pre> and transmission of all RS segments in response. Note that the<o:p></o:p></pre>
<pre> retransmitted CP and RS segments remain part of their original<o:p></o:p></pre>
<pre> retransmission-cycle. Also, a single CP segment may cause multiple<o:p></o:p></pre>
<pre> RS segments to be generated if a reception report would not fit in a<o:p></o:p></pre>
<pre> single data link-MTU-sized RS segment; all RS segments that are part<o:p></o:p></pre>
<pre> of a reception report belong to the same retransmission cycle to<o:p></o:p></pre>
<pre> which the CP segment belongs. In the presence of severe channel<o:p></o:p></pre>
<pre> error conditions, many retransmission cycles may elapse before red-<o:p></o:p></pre>
<pre> part transmission is deemed successful; an implementation may<o:p></o:p></pre>
<pre> therefore impose a retransmission-cycle limit to shield itself from a<o:p></o:p></pre>
<pre> resource-crunch situation. If an LTP sender notices the<o:p></o:p></pre>
<pre> retransmission-cycle limit being exceeded, it SHOULD initiate the<o:p></o:p></pre>
<pre> Cancel Session procedure (<a href="https://tools.ietf.org/html/rfc5326#section-6.19">Section 6.19</a>), queuing a CS segment with<o:p></o:p></pre>
<pre> reason-code RXMTCYCEXC and sending a transmission-session<o:p></o:p></pre>
<pre> cancellation notice (<a href="https://tools.ietf.org/html/rfc5326#section-7.5">Section 7.5</a>) to the client service.<o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<pre><a id="OWAAM6EFC5AB5B5B344C39719CFF5416A2B7D" href="mailto:Felix.Flentge@esa.int"><span style="font-family:"Courier New";text-decoration:none">@Felix.Flentge@esa.int</span></a>: which aspects did you want to make normative?<o:p></o:p></pre>
<pre><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US">Best Regards,<o:p></o:p></span></pre>
<pre><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US"><o:p> </o:p></span></pre>
<pre><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US">Tomaso<o:p></o:p></span></pre>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span lang="EN-US" style="font-size:11.0pt">From:</span></b><span lang="EN-US" style="font-size:11.0pt"> SIS-DTN <sis-dtn-bounces@mailman.ccsds.org>
<b>On Behalf Of </b>Dr. Keith L Scott<br>
<b>Sent:</b> Mittwoch, 24. Februar 2021 17:52<br>
<b>To:</b> sis-dtn@mailman.ccsds.org<br>
<b>Subject:</b> [Sis-dtn] Telecon Notes 20210224<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="p1"><b><span lang="EN-US">SIS-DTN Telecon</span></b><span lang="EN-US"><o:p></o:p></span></p>
<p class="p2"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="p1"><b><span lang="EN-US">LTP</span></b><span lang="EN-US"><o:p></o:p></span></p>
<p class="p3"><span lang="EN-US">Took some notes in the SharePoint List here:<o:p></o:p></span></p>
<p class="p3"><span lang="EN-US"><a href="https://cwe.ccsds.org/fm/wiki/Lists/SISDTN%20LTP%20Update%202021/AllItems.aspx">https://cwe.ccsds.org/fm/wiki/Lists/SISDTN%20LTP%20Update%202021/AllItems.aspx</a>
<o:p></o:p></span></p>
<p class="p1"><b><span lang="EN-US">What testing / experimentation to drive out issues?</span></b><span lang="EN-US"><o:p></o:p></span></p>
<p class="p4"><span lang="EN-US">• LTP Extension Header vs. small Green Blocks to signal adaptive coding and modulation.<o:p></o:p></span></p>
<p class="p4"><span lang="EN-US">• ESA looking to use LTP for optical; no experimentation expected for 8-12 months<o:p></o:p></span></p>
<p class="p1"><b><span lang="EN-US">ReTx cycle limit & Discretionary Checkpoints</span></b><span lang="EN-US"><o:p></o:p></span></p>
<p class="p3"><span lang="EN-US">People to come up with draft clarifying language and we’ll review.<span class="apple-converted-space">
</span>Consult the RFC5326 text to see if we want to ‘normativeize’ it. Keith to collect text from RFC5326 to provide context.<o:p></o:p></span></p>
<p class="p1"><b><span lang="EN-US">BPv7</span></b><span lang="EN-US"><o:p></o:p></span></p>
<p class="p3"><span lang="EN-US">Keith to build a list of items like the LTP list for discussion at next meeting.<o:p></o:p></span></p>
<p class="p1"><b><span lang="EN-US">BPSec</span></b><span lang="EN-US"><o:p></o:p></span></p>
<p class="p3"><span lang="EN-US">In Security WG processing; we need to notify them of status of BPSec doc in IETF.<o:p></o:p></span></p>
<p class="p2"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="p3"><span lang="EN-US">People need to review current draft and we’ll work any proposed changes to the SEA-SEC WG ASAP:<o:p></o:p></span></p>
<p class="p3"><span lang="EN-US"><a href="https://tools.ietf.org/html/draft-ietf-dtn-bpsec-27">https://tools.ietf.org/html/draft-ietf-dtn-bpsec-27</a>
<o:p></o:p></span></p>
<p class="p2"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="p3"><span lang="EN-US">Default security context from IETF is probably not what we want in CCSDS; we might need to define our own set.<o:p></o:p></span></p>
<p class="p2"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="p3"><span lang="EN-US">ESA to start an activity on security.<o:p></o:p></span></p>
<p class="p1"><b><span lang="EN-US">NM Books</span></b><span lang="EN-US"><o:p></o:p></span></p>
<p class="p3"><span lang="EN-US">Links to I-Ds<o:p></o:p></span></p>
<p class="p3"><span lang="EN-US">NM books going through IETF, about to become WG documents, changes as a result of reviews may be coming over the next 8-12 months.<o:p></o:p></span></p>
<p class="p2"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="p3"><span lang="EN-US">ICPA Need Dates for NM updated to <b>2028</b>, we can prioritize the other efforts above these.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:14.0pt"><o:p> </o:p></span></p>
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