<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"><base href="x-msg://1852/"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div>Hi Mohammad,</div><div><br></div><div>I found several inconsistencies in drop tracing (in forwarding strategy and l2-rate-tracer).</div><div>In particular, l2-rate-tracer was recording only "rates" which are calculated using exponential smoothing averaging, this could be one reason for large discrepancies (in case you compared absolute numbers of drops versus rates).</div><div><br></div><div>Another inconsistency is related to what was traced in ndn::ForwardingStrategy. As of the latest commit, I have changed the logic to the following:</div><div><br></div><div>- every time forwarding strategy picks a face to forward (no matter of the actual status of sending out of a particular face), this even is traced as OutInterest or OutData.</div><div><br></div><div>- if status of the send was negative, this will be reported in a separate trace via DropInterest and DropData.</div><div><br></div><div>These DropInterest and DropData are now outputted in ndn::L3RateTracer and ndn::L3AggregateTracer.</div><div><br></div><div>Can you check the updated code?</div><div><br></div><div>---</div><div>Alex</div><div><br></div><br><div><div>On Mar 18, 2013, at 8:56 AM, Hovaidi Ardestani Mohammad <<a href="mailto:mohammad.hovaidi.ardestani@aalto.fi">mohammad.hovaidi.ardestani@aalto.fi</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div lang="EN-GB" link="blue" vlink="purple" style="font-family: Monaco; font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div class="WordSection1" style="page: WordSection1; "><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); ">Hi Alex<o:p></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); ">Thank you for response!<o:p></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); ">The problem is that each consumer is expressing unique interest every time and there should not be any caching in the path, but interestingly, the discrepancy was large enough to convince me to ask this question.<o:p></o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="color: rgb(31, 73, 125); font-family: Calibri, sans-serif; font-size: 11pt; "> </span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125); "> </span></div><div><div style="border-style: solid none none; border-top-width: 1pt; border-top-color: rgb(225, 225, 225); padding: 3pt 0cm 0cm; "><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><b><span lang="EN-US" style="font-size: 11pt; font-family: Calibri, sans-serif; ">From:</span></b><span lang="EN-US" style="font-size: 11pt; font-family: Calibri, sans-serif; "><span class="Apple-converted-space"> </span>Alexander Afanasyev [mailto:cawka1@<a href="http://gmail.com">gmail.com</a>]<span class="Apple-converted-space"> </span><b>On Behalf Of<span class="Apple-converted-space"> </span></b>Alex Afanasyev<br><b>Sent:</b><span class="Apple-converted-space"> </span>Monday, March 18, 2013 4:44 PM<br><b>To:</b><span class="Apple-converted-space"> </span>Hovaidi Ardestani Mohammad<br><b>Cc:</b><span class="Apple-converted-space"> </span><a href="mailto:ndnsim@lists.cs.ucla.edu">ndnsim@lists.cs.ucla.edu</a><br><b>Subject:</b><span class="Apple-converted-space"> </span>Re: [ndnSIM] Number of dropped packets<o:p></o:p></span></div></div></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p> </o:p></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">L2Tracer (there is no ndn namespace) shows number of packets dropped due to queue overflows. In many cases of normal NDN communication, number of incoming interests is not equal to number of outgoing interests (same for data), as NDN router (in general) performing much more operations than just forwarding packets.<o:p></o:p></div><div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p> </o:p></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">For example, if the same data piece is requested from two different neighbors, only the first interest will be forwarded, the second one will be either "collapsed" or satisfied from caches. When Data packet comes, if there is no corresponding PIT entry (or entries), Data packet will be dropped (without L2Tracer knowing it). If there is a PIT entry with multiple incoming faces (or multiple PIT entries), then more than one Data packet will be forwarded out.<o:p></o:p></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p> </o:p></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">At the same time, if you have a simple simulation where consumers requests unique pieces of content, then your formula should be correct, unless you're using forwarding strategy that enforces interest limits (e.g., PerOutFaceLimits). How big is the number discrepancy?<o:p></o:p></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p> </o:p></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">---<o:p></o:p></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">Alex<o:p></o:p></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><o:p> </o:p></div><div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; ">On Mar 18, 2013, at 2:41 AM, Hovaidi Ardestani Mohammad <<a href="mailto:mohammad.hovaidi.ardestani@aalto.fi" style="color: purple; text-decoration: underline; ">mohammad.hovaidi.ardestani@aalto.fi</a>> wrote:<o:p></o:p></div></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><br><br><o:p></o:p></div><blockquote style="margin-top: 5pt; margin-bottom: 5pt; "><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; ">Hello everybody!<o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; ">I am thinking that the following formula should give us the number of dropped packets.<o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; ">Number of Dropped packets = (Number of received interests + number of received data packets) - (Number of sent interests + number of sent data packets).<o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; ">If above formula is correct, then why on earth number of dropped packets shown by ndn::L2RateTracer is not equal with that?<o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; ">Thank you for your response in advance!<o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; ">-Mohammad<o:p></o:p></span></div></div><div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 11pt; font-family: Calibri, sans-serif; "> <o:p></o:p></span></div></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "><span style="font-size: 13.5pt; font-family: Monaco, serif; ">_______________________________________________<br>ndnSIM mailing list<br><a href="mailto:ndnSIM@lists.cs.ucla.edu" style="color: purple; text-decoration: underline; "><span style="color: rgb(149, 79, 114); ">ndnSIM@lists.cs.ucla.edu</span></a><br><a href="http://www.lists.cs.ucla.edu/mailman/listinfo/ndnsim" style="color: purple; text-decoration: underline; "><span style="color: rgb(149, 79, 114); ">http://www.lists.cs.ucla.edu/mailman/listinfo/ndnsim</span></a><o:p></o:p></span></div></blockquote></div><p class="MsoNormal" style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif; "></p></div></div></div></div></div></blockquote></div><br></body></html>