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<div class="elementToProof" style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
Dear friends,</div>
<div class="elementToProof" style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
I am pleased to inform all people interested in LTP development and testing that at Unibo we have developed a simple but effective tool to filter LTP segments, called LTPDrop. The code is released under GPLv3 and can be downloaded from:</div>
<div class="elementToProof"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"><a href="https://gitlab.com/unibo-dtn/ltpdrop">https://gitlab.com/unibo-dtn/ltpdrop</a></span></div>
<div class="elementToProof"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">The main branch contains the latest version.</span></div>
<p class="elementToProof" style="margin-top: 0px; margin-bottom: 0px;"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"><br>
</span></p>
<div class="elementToProof" style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
>From the Git Lab description:</div>
<p class="elementToProof" style="margin-top: 0px; margin-bottom: 0px;"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">LTPDrop is a command line Python program
designed to filter LTP segments belonging to session started by one LTP engine; it enables to filter/log specific LTP segment types. LTPDrop can be used to:</span></p>
<ol start="1" style="direction: ltr; list-style-type: decimal;" data-sourcepos="4:1-7:0" data-listchain="__List_Chain_1026">
<li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">Deterministically drop the first instances of specific LTP segment types</span></li><li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">Randomly drop LTP segments with a given probability</span></li><li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">Log LTP sessions</span></li></ol>
<p style="direction: ltr;" class="elementToProof"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">The current version of this program is compatible with
<a href="https://datatracker.ietf.org/doc/rfc5326/" target="_blank" id="OWAce5be6fa-0803-05f4-0697-eb84451d5d56" class="OWAAutoLink" rel="nofollow noreferrer noopener" style="margin-top: 0px; margin-bottom: 0px;" data-sourcepos="8:56-8:112" data-loopstyle="linkonly">
LTP RFC-5326</a> and <a href="https://doi.org/10.1109/TAES.2022.3176847" target="_blank" id="OWA43ae298b-d33f-dfe6-afd0-f7f12187564a" class="OWAAutoLink" rel="nofollow noreferrer noopener" style="margin-top: 0px; margin-bottom: 0px;" data-sourcepos="8:118-8:176" data-loopstyle="linkonly">
Multicolor LTP</a>. </span></p>
<p style="direction: ltr;" class="elementToProof"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"><br>
</span></p>
<p style="direction: ltr;" class="elementToProof"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">A few notes.</span></p>
<p style="direction: ltr;" class="elementToProof"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">Use 1 is intended to check the ability of the LTP implementation
under test to correctly respond to the loss of specific segments, thus reproducing uncommon situations, such as the loss of the first CP, or the loss of the first RA, or the loss of the first N RS, etc.</span></p>
<p style="direction: ltr;" class="elementToProof"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"><br>
</span></p>
<p style="direction: ltr;" class="elementToProof"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">Use 2 has been thought in alternative to use 1, when the user
just need to inject random losses; however, it can be used in parallel too; in the latter case random losses are applied before deterministic losses.</span></p>
<p style="direction: ltr;" class="elementToProof"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"><br>
</span></p>
<p style="direction: ltr;" class="elementToProof"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">Use 3 allows the user to log in a .csv file the LTP traffic (as
a sort of specialized "tcpdump"). In the file there will be one line for each segment seen in input, with many fields, including a timestamp and the LTP type. By importing the .csv file it is easy to extract information about a session (the session duration,
if there were retransmissions, etc..).</span></p>
<p style="direction: ltr;" class="elementToProof"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">.csv Logs refer to input traffic, i.e. before losses are applied.</span></p>
<p style="direction: ltr;" class="elementToProof"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"><br>
</span></p>
<p style="direction: ltr;" class="elementToProof"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">Concerning the support of Muticolor LTP, this means that LTPDrop
recognizes as experimental "Orange" segments the 4 LTP types left free by RFC 5326. In other words, LTPDrop can selectively drop them on request, as all other segments, and these segments are classified as Orange segments in logs. On standard LTP traffic
this types should never appear, thus the extension is transparent to standard LTP traffic.</span></p>
<p style="direction: ltr;" class="elementToProof"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"><br>
</span></p>
<p style="direction: ltr;" class="elementToProof"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">The program has been written by Martino Manaresi as a part of
his undergraduate thesis in computer science engineering. Let me add that it is his own idea, after noting that it was difficult to recreate "corner cases" in compatibility tests between ION and ESA-BP implementations of LTP. I just supervised the project.</span></p>
<p style="direction: ltr;" class="elementToProof"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"><br>
</span></p>
<p style="direction: ltr;" class="elementToProof"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">Martino and I look forward to receiving your comments and suggestions,
as well as possible bug indications.</span></p>
<p style="direction: ltr;" class="elementToProof"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"><br>
</span></p>
<p style="direction: ltr;" class="elementToProof"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">Yours,</span></p>
<p style="direction: ltr;" class="elementToProof"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"> Carlo</span></p>
<p style="direction: ltr;" class="elementToProof"><span style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);"><br>
</span></p>
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</span></p>
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</span></p>
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