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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Cheol,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>I agree with what Felix has mentioned and I will strongly encourage to use the IANA allocated port number where possible and let your network stack or OS deal with multiplexing TCP connections. Having all (or as many as possible) hosts listening on standard ports will avoid the need to customize each new node/host.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>And this is not something DTN- or BP-specific, using standard port numbers generally will help with middleboxes and tools like Wireshark or scapy to need less configuration from the default.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><div style='border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt'><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>From:</span></b><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'> chkoo@kari.re.kr <chkoo@kari.re.kr> <br><b>Sent:</b> Thursday, September 7, 2023 7:10 AM<br><b>To:</b> Felix Flentge <Felix.Flentge@esa.int><br><b>Cc:</b> Sipos, Brian J. <Brian.Sipos@jhuapl.edu>; Gao, Jay L (JPL-332C)[JPL Empl <jay.l.gao@jpl.nasa.gov>; sburleig.sb@gmail.com; Torgerson, J. Leigh (US 332C) <jordan.l.torgerson@jpl.nasa.gov>; Keith Scott <keithlscott@gmail.com>; Wilmot, Jonathan J. (GSFC-580. <jonathan.j.wilmot@nasa.gov>; Carlo Caini <carlo.caini@unibo.it>; sis-dtn@mailman.ccsds.org<br><b>Subject:</b> [EXT] RE: Is there a standardized way to implement/configure TCP convergence layer for Bundle transaction?<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><div id=APLWarningText><table class=MsoNormalTable border=0 cellspacing=0 cellpadding=0 align=left><tr><td width="100%" style='width:100.0%;background:#E0E0E0;padding:0in 0in 0in 0in'><p class=MsoNormal style='mso-element:frame;mso-element-frame-hspace:1.8pt;mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:column;mso-height-rule:exactly'><b><span style='color:red'>APL external email warning: </span></b><span style='color:black'>Verify sender chkoo@kari.re.kr before clicking links or attachments</span><o:p></o:p></p></td></tr></table><p> <o:p></o:p></p></div></div><p><span style='font-size:10.0pt;font-family:"Gulim",serif'>RFC 9174! I just quick reviewed the document and found that 4556 is the allocated TCP port number and information that I need (Thanks to</span><span style='font-size:10.0pt'> </span><span style='font-size:9.0pt;font-family:"Gulim",serif;color:#333333'>Sipos Brian J.)</span><span style='font-size:10.0pt;font-family:"Gulim",serif'><o:p></o:p></span></p><p><span style='font-size:10.0pt;font-family:"Gulim",serif'><o:p> </o:p></span></p><p><span style='font-size:10.0pt;font-family:"Gulim",serif'>Cheol<o:p></o:p></span></p><div style='margin-left:9.6pt;margin-top:22.5pt'><p class=MsoNormal><b><span style='font-size:9.0pt;font-family:Dotum;color:#0066CC'>--------- 원본 메일 ---------<o:p></o:p></span></b></p></div><blockquote style='border:none;border-left:solid windowtext 1.5pt;padding:0in 0in 0in 12.0pt;margin-left:9.6pt;margin-top:5.0pt;margin-right:0in;margin-bottom:5.0pt'><div><p class=MsoNormal><b><span style='font-size:9.0pt;font-family:"Malgun Gothic",sans-serif'>보낸사람</span></b><span style='font-size:9.0pt;font-family:"Arial",sans-serif'> : Felix Flentge <Felix.Flentge@esa.int><br></span><b><span style='font-size:9.0pt;font-family:"Malgun Gothic",sans-serif'>받는사람</span></b><span style='font-size:9.0pt;font-family:"Arial",sans-serif'> : "chkoo@kari.re.kr" <chkoo@kari.re.kr>, "Sipos Brian J." <Brian.Sipos@jhuapl.edu><br></span><b><span style='font-size:9.0pt;font-family:"Malgun Gothic",sans-serif'>참조</span></b><span style='font-size:9.0pt;font-family:"Arial",sans-serif'> : "Gao, Jay L (JPL-332C)[JPL Empl" <jay.l.gao@jpl.nasa.gov>, "sburleig.sb@gmail.com" <sburleig.sb@gmail.com>, "Torgerson, J. Leigh (US 332C)" <jordan.l.torgerson@jpl.nasa.gov>, Keith Scott <keithlscott@gmail.com>, "Wilmot, Jonathan J. (GSFC-580." <jonathan.j.wilmot@nasa.gov>, Carlo Caini <carlo.caini@unibo.it>, "sis-dtn@mailman.ccsds.org" <sis-dtn@mailman.ccsds.org><br></span><b><span style='font-size:9.0pt;font-family:"Malgun Gothic",sans-serif'>받은날짜</span></b><span style='font-size:9.0pt;font-family:"Arial",sans-serif'> : 2023-09-07 (</span><span style='font-size:9.0pt;font-family:"Malgun Gothic",sans-serif'>목</span><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>) 19:05:36<br></span><b><span style='font-size:9.0pt;font-family:"Malgun Gothic",sans-serif'>제목</span></b><span style='font-size:9.0pt;font-family:"Arial",sans-serif'> : RE: RE: Is there a standardized way to implement/configure TCP convergence layer for Bundle transaction?<o:p></o:p></span></p><div style='margin-top:3.75pt'><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>Hi,<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'> <o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>It seems that we are mixing standardisation, conventions and implementations.<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'> <o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>From the standardisation perspective, I don’t see any interoperability issue (I just did a quick review RfC 9174). If there are, these should be addressed in IETF.<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'> <o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>The use of specific UDP ports for LTP according to engine id is nothing more then a convention for specific implementations. Running LTP over UDP can use any port you agree. (Anyway, I would typically suggest to use TCPCL for terrestrial communication).<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'> <o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>I think the real underlying question is how to know to connect to a specific node (which CL to use, which parameters, …). Currently, we specify this in ICDs. In the future we may use discovery mechanisms (I think there is on-going work), network management, registries (some people proposed the SANA sites & apertures) or something else to get such information.<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'> <o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>Regards,<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>Felix<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'> <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 style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><b><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>From:</span></b><span style='font-size:9.0pt;font-family:"Arial",sans-serif'> chkoo@kari.re.kr <chkoo@kari.re.kr> <br><b>Sent:</b> Wednesday, September 6, 2023 11:32 PM<br><b>To:</b> Sipos Brian J. <Brian.Sipos@jhuapl.edu><br><b>Cc:</b> Gao, Jay L (JPL-332C)[JPL Empl <jay.l.gao@jpl.nasa.gov>; Felix Flentge <Felix.Flentge@esa.int>; sburleig.sb@gmail.com; Torgerson, J. Leigh (US 332C) <jordan.l.torgerson@jpl.nasa.gov>; Keith Scott <keithlscott@gmail.com>; Wilmot, Jonathan J. (GSFC-580. <jonathan.j.wilmot@nasa.gov>; Carlo Caini <carlo.caini@unibo.it>; sis-dtn@mailman.ccsds.org<br><b>Subject:</b> RE: RE: Is there a standardized way to implement/configure TCP convergence layer for Bundle transaction?<o:p></o:p></span></p></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'> <o:p></o:p></span></p><p style='margin-left:.5in'><span style='font-size:10.0pt;font-family:"Gulim",serif'>Hi, Brian S.</span><span style='font-size:9.0pt;font-family:"Arial",sans-serif'><o:p></o:p></span></p><p style='margin-left:.5in'><span style='font-size:10.0pt;font-family:"Arial",sans-serif'> </span><span style='font-size:9.0pt;font-family:"Arial",sans-serif'><o:p></o:p></span></p><p style='margin-left:.5in'><span style='font-size:10.0pt;font-family:"Gulim",serif'>Yes, either way has benefits, and there are no technical issues. Absolutely, there is no need to argue about which one is more correct.</span><span style='font-size:9.0pt;font-family:"Arial",sans-serif'><o:p></o:p></span></p><p style='margin-left:.5in'><span style='font-size:10.0pt;font-family:"Arial",sans-serif'> </span><span style='font-size:9.0pt;font-family:"Arial",sans-serif'><o:p></o:p></span></p><p style='margin-left:.5in'><span style='font-size:10.0pt;font-family:"Gulim",serif'>Interfacing to another neighbor node through LTPCL over UDP is quite straightforward since it only needs to transmit all the LTP segmentation data to *113 UDP port (1113, 2113, 3113, and so on, according to the LTP node number).</span><span style='font-size:9.0pt;font-family:"Arial",sans-serif'><o:p></o:p></span></p><p style='margin-left:.5in'><span style='font-size:10.0pt;font-family:"Arial",sans-serif'> </span><span style='font-size:9.0pt;font-family:"Arial",sans-serif'><o:p></o:p></span></p><p style='margin-left:.5in'><span style='font-size:10.0pt;font-family:"Gulim",serif'>Of course, LTPCL over UDP can be used with multiplexing. It is technically fine. However, it does affect the configuration parameters' effort, so every node must know the contact information for how the opposite side allocates the reception port in the range of 1 to 65535.</span><span style='font-size:9.0pt;font-family:"Arial",sans-serif'><o:p></o:p></span></p><p style='margin-left:.5in'><span style='font-size:10.0pt;font-family:"Arial",sans-serif'> </span><span style='font-size:9.0pt;font-family:"Arial",sans-serif'><o:p></o:p></span></p><p style='margin-left:.5in'><span style='font-size:10.0pt;font-family:"Gulim",serif'>I think TCPCL has the same issue. Do we want to allocate a port number for this, e.g., xxx019 for dedicated use? Or do we want to reserve preferred port numbers from agencies, such as 1 to 1000 for NASA, 1000 to 2000 for ESA, 2000 to 3000 for KARI, and so on?</span><span style='font-size:9.0pt;font-family:"Arial",sans-serif'><o:p></o:p></span></p><p style='margin-left:.5in'><span style='font-size:10.0pt;font-family:"Arial",sans-serif'> </span><span style='font-size:9.0pt;font-family:"Arial",sans-serif'><o:p></o:p></span></p><p style='margin-left:.5in'><span style='font-size:10.0pt;font-family:"Gulim",serif'>Cheol</span><span style='font-size:9.0pt;font-family:"Arial",sans-serif'><o:p></o:p></span></p><div style='margin-left:9.6pt;margin-top:22.5pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><b><span style='font-size:9.0pt;font-family:Dotum;color:#0066CC'>--------- 원본 메일 ---------</span></b><span style='font-size:9.0pt;font-family:"Arial",sans-serif'><o:p></o:p></span></p></div><blockquote style='border:none;border-left:solid windowtext 1.5pt;padding:0in 0in 0in 12.0pt;margin-left:9.6pt;margin-top:5.0pt;margin-right:0in;margin-bottom:5.0pt'><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><b><span style='font-size:9.0pt;font-family:"Malgun Gothic",sans-serif'>보낸사람</span></b><span style='font-size:9.0pt;font-family:"Arial",sans-serif'> : "Sipos, Brian J." <</span><a href="mailto:Brian.Sipos@jhuapl.edu"><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>Brian.Sipos@jhuapl.edu</span></a><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>><br></span><b><span style='font-size:9.0pt;font-family:"Malgun Gothic",sans-serif'>받는사람</span></b><span style='font-size:9.0pt;font-family:"Arial",sans-serif'> : "</span><span style='font-size:9.0pt;font-family:"Malgun Gothic",sans-serif'>구철회</span><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>" <</span><a href="mailto:chkoo@kari.re.kr"><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>chkoo@kari.re.kr</span></a><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>>, "Gao, Jay L (JPL-332C)[JPL Empl" <</span><a href="mailto:jay.l.gao@jpl.nasa.gov"><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>jay.l.gao@jpl.nasa.gov</span></a><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>>, Felix Flentge <</span><a href="mailto:Felix.Flentge@esa.int"><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>Felix.Flentge@esa.int</span></a><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>>, "</span><a href="mailto:sburleig.sb@gmail.com"><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>sburleig.sb@gmail.com</span></a><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>" <</span><a href="mailto:sburleig.sb@gmail.com"><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>sburleig.sb@gmail.com</span></a><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>>, "Torgerson, J. Leigh (US 332C)" <</span><a href="mailto:jordan.l.torgerson@jpl.nasa.gov"><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>jordan.l.torgerson@jpl.nasa.gov</span></a><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>>, Keith Scott <</span><a href="mailto:keithlscott@gmail.com"><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>keithlscott@gmail.com</span></a><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>>, "Wilmot, Jonathan J. (GSFC-580." <</span><a href="mailto:jonathan.j.wilmot@nasa.gov"><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>jonathan.j.wilmot@nasa.gov</span></a><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>>, Carlo Caini <</span><a href="mailto:carlo.caini@unibo.it"><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>carlo.caini@unibo.it</span></a><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>><br></span><b><span style='font-size:9.0pt;font-family:"Malgun Gothic",sans-serif'>받은날짜</span></b><span style='font-size:9.0pt;font-family:"Arial",sans-serif'> : 2023-09-07 (</span><span style='font-size:9.0pt;font-family:"Malgun Gothic",sans-serif'>목</span><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>) 02:51:05<br></span><b><span style='font-size:9.0pt;font-family:"Malgun Gothic",sans-serif'>제목</span></b><span style='font-size:9.0pt;font-family:"Arial",sans-serif'> : RE: Is there a standardized way to implement/configure TCP convergence layer for Bundle transaction?<o:p></o:p></span></p><div style='margin-top:3.75pt'><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif;color:#1F497D'>Cheol,</span><span style='font-size:9.0pt;font-family:"Arial",sans-serif'><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif;color:#1F497D'>While the TCPCL allows many possible strategies, as you point out, I’m not sure that these represent barriers to interoperability. If a passive TCPCL entity chooses to listen on one port or may separate ports, it doesn’t (or shouldn’t) affect the ability of a peer to attempt to establish a TCPCL session. There may be specific policy on a node that refuses connections or terminates sessions based on the peer parameters, but this seems like a policy or configuration alignment issue and not necessarily lack of interoperability (the node can be capable of interoperating but chooses by policy not to do so).</span><span style='font-size:9.0pt;font-family:"Arial",sans-serif'><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif;color:#1F497D'> </span><span style='font-size:9.0pt;font-family:"Arial",sans-serif'><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif;color:#1F497D'>I would be interested to see specific examples or hurdles with TCPCL practice, because if there are special cases that lead to trouble these should at least be captured as errata for RFC 9174 or as updated recommended practice.</span><span style='font-size:9.0pt;font-family:"Arial",sans-serif'><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif;color:#1F497D'> </span><span style='font-size:9.0pt;font-family:"Arial",sans-serif'><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif;color:#1F497D'>LTP on the other hand, because it lacks a strong binding to its segment transport, can cause headaches with middleboxes (for example when using UDP transport can confuse NAT and firewalls because it isn’t guaranteed to use a single 5-tuple “conversation” the way other UDP applications typically do). This also has beneficial side effects related to multi-homing though, so there isn’t really a right or wrong way.</span><span style='font-size:9.0pt;font-family:"Arial",sans-serif'><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif;color:#1F497D'> </span><span style='font-size:9.0pt;font-family:"Arial",sans-serif'><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif;color:#1F497D'>Thanks for any feedback,</span><span style='font-size:9.0pt;font-family:"Arial",sans-serif'><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif;color:#1F497D'>Brian S.</span><span style='font-size:9.0pt;font-family:"Arial",sans-serif'><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif;color:#1F497D'> </span><span style='font-size:9.0pt;font-family:"Arial",sans-serif'><o:p></o:p></span></p><div style='border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt'><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in;text-autospace:ideograph-other'><b><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>From:</span></b><span style='font-size:9.0pt;font-family:"Arial",sans-serif'> SIS-DTN <</span><a href="mailto:sis-dtn-bounces@mailman.ccsds.org"><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>sis-dtn-bounces@mailman.ccsds.org</span></a><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>> <b>On Behalf Of </b>??? via SIS-DTN<br><b>Sent:</b> Wednesday, September 6, 2023 12:29 AM<br><b>To:</b> 'Gao, Jay L (JPL-332C)[JPL Employee]' <</span><a href="mailto:jay.l.gao@jpl.nasa.gov"><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>jay.l.gao@jpl.nasa.gov</span></a><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>>; 'Felix Flentge' <</span><a href="mailto:Felix.Flentge@esa.int"><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>Felix.Flentge@esa.int</span></a><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>>; </span><a href="mailto:sburleig.sb@gmail.com"><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>sburleig.sb@gmail.com</span></a><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>; Torgerson, J. Leigh (US 332C) <</span><a href="mailto:jordan.l.torgerson@jpl.nasa.gov"><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>jordan.l.torgerson@jpl.nasa.gov</span></a><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>>; 'Keith Scott' <</span><a href="mailto:keithlscott@gmail.com"><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>keithlscott@gmail.com</span></a><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>>; 'Wilmot, Jonathan J. (GSFC-580.0)[VANTAGE SYSTEMS INC <</span><a href="mailto:jonathan.j.wilmot@nasa.gov"><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>jonathan.j.wilmot@nasa.gov</span></a><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>>; 'Carlo Caini' <</span><a href="mailto:carlo.caini@unibo.it"><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>carlo.caini@unibo.it</span></a><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>><br><b>Cc:</b> </span><a href="mailto:sis-dtn@mailman.ccsds.org"><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>sis-dtn@mailman.ccsds.org</span></a><span style='font-size:9.0pt;font-family:"Arial",sans-serif'><br><b>Subject:</b> [EXT] [Sis-dtn] Is there a standardized way to implement/configure TCP convergence layer for Bundle transaction?<o:p></o:p></span></p></div></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'> <o:p></o:p></span></p><div><div id=APLWarningText><table class=MsoNormalTable border=0 cellspacing=0 cellpadding=0 align=left width="100%" style='width:100.0%'><tr><td width="100%" style='width:100.0%;background:#E0E0E0;padding:0in 0in 0in 0in'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-autospace:ideograph-other;mso-element:frame;mso-element-frame-hspace:1.8pt;mso-element-wrap:around;mso-element-anchor-vertical:paragraph;mso-element-anchor-horizontal:column;mso-height-rule:exactly'><b><span style='font-family:"Gulim",serif;color:red'>APL external email warning: </span></b><span style='font-family:"Gulim",serif;color:black'>Verify sender </span><a href="mailto:sis-dtn-bounces@mailman.ccsds.org"><span style='font-family:"Gulim",serif'>sis-dtn-bounces@mailman.ccsds.org</span></a><span style='font-family:"Gulim",serif;color:black'> before clicking links or attachments</span><o:p></o:p></p></td></tr></table><p style='margin-left:.5in'><span style='font-size:10.0pt'> </span><span style='font-size:9.0pt;font-family:"Arial",sans-serif'><o:p></o:p></span></p></div></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>Hi Fellows<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'> <o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>Recently, I began to consider that the implementation of the TCP convergence layer, which conveys Bundles reliably, can be source of interoperability issues among various DTN implementations.<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>There is freedom in designing the TCP interface, with options like allocating a single TCP port to a node and multiplexing neighbor input, or allocating multiple TCP ports for each neighbor's transaction input.<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'> <o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>Some implementations perform an interrogation step to obtain multiplexing information from neighboring nodes, such as IPN/DTN address.<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>Some implementations prefer multiple TCP daemons for connecting with neighbors.<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>In either case, DTN software may need to implement a specialized UTA or CLA interface for interfacing with various other DTN software via TCP convergence layer.<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'> <o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>Is there a standardized way to do it? Or do we want to discuss about a standardized way here?<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'> <o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>On the contrary, LTP, as a Convergence Layer, is a straightforward mechanism and a point-to-point protocol that simplifies Bundle input multiplexing, resulting in fewer interoperability issues, in my opinion. LTPCL is useful at the ground-space link, however TCPCL can be more suitable choice for terrestrial link. So, I think, TCPCL needs more attention for future DTN usage.<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'> <o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>Best,<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>Cheol<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'> <o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'> <o:p></o:p></span></p></div></div></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif'> <o:p></o:p></span></p></div></blockquote><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:.5in'><span style='font-size:9.0pt;font-family:"Arial",sans-serif;border:solid windowtext 1.0pt;padding:0in'><img border=0 width=1 height=1 style='width:.0083in;height:.0083in' id="Picture_x0020_3" src="cid:image002.jpg@01D9E176.38DABC70" alt="Image removed by sender."></span><span style='font-size:9.0pt;font-family:"Arial",sans-serif'><o:p></o:p></span></p></div><p class=MsoNormal><span style='font-size:9.0pt;font-family:"Arial",sans-serif'>This message is intended only for the recipient(s) named above. It may contain proprietary information and/or protected content. Any unauthorised disclosure, use, retention or dissemination is prohibited. If you have received this e-mail in error, please notify the sender immediately. ESA applies appropriate organisational measures to protect personal data, in case of data privacy queries, please contact the ESA Data Protection Officer (dpo@esa.int). <o:p></o:p></span></p></div><p class=MsoNormal><span style='font-size:9.0pt;font-family:"Arial",sans-serif'><o:p> </o:p></span></p></div></blockquote><p class=MsoNormal><span style='border:solid windowtext 1.0pt;padding:0in'><img border=0 width=100 height=100 style='width:1.0416in;height:1.0416in' id="Picture_x0020_2" src="cid:~WRD000.jpg" alt="Image removed by sender."></span><o:p></o:p></p></div></div></body></html>