<html><head><meta http-equiv="Content-Type" content="text/html charset=iso-2022-jp"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div>Hi huyao,</div><div><br></div><div>This RTO refers only to retry for end-user retransmission. Intermediate nodes, at least in the currently implemented strategies in ndnSIM, don't retry alternative faces, unless they receive a retransmitted interest from the end-user (retransmitted interest = interest for which there is an existing PIT entry, and interest is received from the face, from which the node already received the interest for the same name before).</div><div><br></div><div>---</div><div>Alex</div><br><div><div>On May 29, 2013, at 7:38 AM, yao hu <<a href="mailto:huyao@goto.info.waseda.ac.jp">huyao@goto.info.waseda.ac.jp</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div dir="ltr">Hi Alex and Yaogong,<div><br></div><div style="">Thanks for your both explanations. For my understanding, this RTO is used in setting up a retry-timer. But I am a little confused by the word "retry" in "retry-timer". This "retry" refers to the retransmission for end users for sure, but it also refers to the retry for intermediate nodes (retry other alternative faces than failed one)? </div>
<div style=""><br></div><div style="">Regards,</div><div style="">huyao</div><div style=""><br></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">2013/5/29 Alex Afanasyev <span dir="ltr"><<a href="mailto:alexander.afanasyev@ucla.edu" target="_blank">alexander.afanasyev@ucla.edu</a>></span><br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word">Hi Yaogong,<div><br></div><div>Thanks for opening an issue and finding the problem! I just incorporated your commit that fixes the incorrect initialization of attributes.</div>
<div><br></div><div>As of now, the initial RTO is 1 second, and later cannot become smaller than the minimum, which is by default set to 200ms.</div><div><br></div><div>---</div><div>Alex</div><div><div class="h5"><br>
<div><div>On May 28, 2013, at 8:21 AM, Yaogong Wang <<a href="mailto:ywang15@ncsu.edu" target="_blank">ywang15@ncsu.edu</a>> wrote:</div><br><blockquote type="cite"><div dir="ltr">Hi Alex,<div><br></div><div>I believe the initial RTO should not be 200ms. According to the code, RTO is set to <span style="color:rgb(51,51,51);font-family:Consolas,'Liberation Mono',Courier,monospace;font-size:12px;line-height:18px;white-space:pre-wrap">m_currentEstimatedRtt + 4 * </span><span style="color:rgb(51,51,51);font-family:Consolas,'Liberation Mono',Courier,monospace;font-size:12px;line-height:18px;white-space:pre-wrap">m_variance</span> bounded by minRto and maxRto. By default, <span style="color:rgb(51,51,51);font-family:Consolas,'Liberation Mono',Courier,monospace;font-size:12px;line-height:18px;white-space:pre-wrap">m_currentEstimatedRtt</span> is initially set to 1s (<span style="font-family:Consolas,'Liberation Mono',Courier,monospace;font-size:12px;line-height:18px;white-space:pre-wrap">InitialEstimation</span>) and <span style="color:rgb(51,51,51);font-family:Consolas,'Liberation Mono',Courier,monospace;font-size:12px;line-height:18px;white-space:pre-wrap">m_variance</span> to 0. Hence, the initial RTO should be 1s which is within minRto=200ms and maxRto=200s.</div>
<div><br></div><div>The current code does set initial RTO to 200ms due to a bug that sets <span style="color:rgb(51,51,51);font-family:Consolas,'Liberation Mono',Courier,monospace;font-size:12px;line-height:18px;white-space:pre-wrap">m_currentEstimatedRtt</span> to 0 initially. I have reported the bug here: <a href="https://github.com/NDN-Routing/ndnSIM/issues/40" target="_blank">https://github.com/NDN-Routing/ndnSIM/issues/40</a></div>
<div><br></div><div>Thanks,</div><div>Yaogong</div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Wed, May 22, 2013 at 4:40 PM, Alex Afanasyev <span dir="ltr"><<a href="mailto:alexander.afanasyev@ucla.edu" target="_blank">alexander.afanasyev@ucla.edu</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word">Hi huyao,<div><br></div><div>Yes. There is an initial RTO value and it is 200ms. You can control this value by setting "ns3::ndn::RttEstimator::MinRTO" value. ndnSIM uses a modified version of RTT estimator, originally in Internet module: <a href="https://github.com/NDN-Routing/ndnSIM/blob/master/utils/ndn-rtt-estimator.cc" target="_blank">https://github.com/NDN-Routing/ndnSIM/blob/master/utils/ndn-rtt-estimator.cc</a>.</div>
<div><br></div><div>--</div><div>Alex</div><div><br></div><div><div><div><div>On May 22, 2013, at 10:52 AM, yao hu <<a href="mailto:huyao0107@gmail.com" target="_blank">huyao0107@gmail.com</a>> wrote:</div>
<br></div><blockquote type="cite"><div><div dir="ltr"><font face="arial, helvetica, sans-serif">Hi Alex,</font><div><font face="arial, helvetica, sans-serif"><br></font></div><div><font face="arial, helvetica, sans-serif">Is there a default initial RTO value for consumer node? RTO should be calculated based on the observed RTT samples, but how about the first Interest timeout for some reason? If there is a default initial value, is it 200ms?</font></div>
<div><font face="arial, helvetica, sans-serif"><br></font></div><div><font face="arial, helvetica, sans-serif">Thanks for your explanation~</font></div><div><font face="arial, helvetica, sans-serif"><br></font></div>
<div><font face="arial, helvetica, sans-serif">Regards,</font></div><div><font face="arial, helvetica, sans-serif">huyao</font></div><div><br></div><div><div style="font-family:monospace,fixed;font-size:13px;line-height:1;min-height:13px;white-space:pre-wrap;word-wrap:break-word;padding-left:53px;padding-bottom:0px;margin:0px">
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<br></blockquote></div><br><br clear="all"><div><br></div>-- <br>============================<br>Yaogong Wang, PhD Candidate<br>Department of Computer Science<br>North Carolina State University<br><a href="http://www4.ncsu.edu/~ywang15/" target="_blank">http://www4.ncsu.edu/~ywang15/</a><br>
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