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<p class="MsoNormal"><span style="font-size:12.0pt">SLS-SLP colleagues ---<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt">Section 3.2.2.2 of the <i>Encapsulation Packet Protocol</i> Blue Book (CCSDS 133.1-B-3) specifies the content of the SDLP_Channel for the various underlying space data link protocols (SDLPs):<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:12.0pt;font-family:"TimesNewRomanPSMT",serif">“a) for the Virtual Channel Packet (VCP) service of TM (reference [1]), TC (reference [2]),<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:12.0pt;font-family:"TimesNewRomanPSMT",serif">or AOS (reference [3]), SDLP_Channel shall contain the Global Virtual Channel<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:12.0pt;font-family:"TimesNewRomanPSMT",serif">Identifier (GVCID);<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:12.0pt;font-family:"TimesNewRomanPSMT",serif">b) for the MAP Packet (MAPP) service of TC (reference [2]) and USLP (reference [5]),<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"TimesNewRomanPSMT",serif">SDLP_Channel shall contain the Global MAP ID (GMAP ID);<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:12.0pt;font-family:"TimesNewRomanPSMT",serif">c) for the Packet Service of Proximity-1 (reference [4]), SDLP_Channel shall contain the<o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:12.0pt;font-family:"TimesNewRomanPSMT",serif">Transfer Frame Version Number, the Spacecraft Identifier (SCID), the Physical<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"TimesNewRomanPSMT",serif">Channel Identifier (PCID), the Data Field Construction ID (DFC_ID), and the Port ID.”</span><o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-size:12.0pt">Missing from this list is any mention of the
<u>Virtual Channel Packet service of TC</u> (section 3.4 of CCSDS 232.0-B-3. Was this exclusion accidental or intentional – i.e., is Encapsulation over the TC VC Packet service disallowed? I suggest that the issue be resolved unambiguously one way or the other
– that is, either add it to the list of SDLP_Channels that contain GVCIDs or add a note that explicitly rules out in that usage.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt">Thanks.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt">Best regards,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt">John<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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