<div dir="ltr">Hi Obaid<div><br></div><div>This is what I have from <a href="http://yoursunny.com/p/ndn6/">ndn6.tk</a> to UCLA:</div><div><div><font face="courier new, monospace">--- 2607:f010:3f9::11:0 ping statistics ---</font></div>
<div><font face="courier new, monospace">20 packets transmitted, 20 received, 0% packet loss, time 19019ms</font></div><div><font face="courier new, monospace">rtt min/avg/max/mdev = 141.671/142.007/143.969/0.672 ms</font></div>
</div><div><div><font face="courier new, monospace"><br></font></div><div><font face="courier new, monospace">=== Ping Statistics For /ndn/edu/ucla ===</font></div><div><font face="courier new, monospace">Sent=20, Received=20, Packet Loss=0%, Total Time=3115.14 ms</font></div>
<div><font face="courier new, monospace">Round Trip Time (Min/Max/Avg/MDev) = (150.608/186.74/155.757/7.46211) ms</font></div></div><div><br></div><div>On average, ndnping is 12ms slower than ICMP ping. A few factors contribute to this fact:</div>
<div><ul><li>kernel vs userspace</li><ul><li>ICMP ping is responded by OS kernel.</li><li>ndnping is handled by at least two userspace processes on each end.</li></ul><li>signing</li><ul><li>ICMP ping reply is a simple unsigned packet.</li>
<li>ndnpingserver needs to sign the reply Data with RSA. <a href="http://redmine.named-data.net/issues/1589">Signing is slow</a>, and we <a href="http://redmine.named-data.net/issues/1851">can't switch</a> to SHA256 digest now.</li>
</ul><li>caching</li><ul><li>ICMP ping reply is not cached.</li><li>NFD has in-network cache. ContentStore implementation is <a href="http://redmine.named-data.net/issues/1706">inefficient</a>.</li></ul></ul></div><div>ndnping variance is 7ms higher than ICMP ping, especially on the first request. This is mainly due to the behavior of NCC strategy.</div>
<div><br></div><div>Yours, Junxiao<br><div class="gmail_extra"><br><br><div class="gmail_quote">On Tue, Aug 26, 2014 at 11:51 PM, Syed Obaid Amin <span dir="ltr"><<a href="mailto:obaidasyed@gmail.com" target="_blank">obaidasyed@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div dir="ltr">Hello All, <div><br></div><div>I am observing that ndnping is taking much time in processing the packets. For e.g. have a look at the following traces. There is approx 100ms difference between a regular ping and ndnping (besides the first packet). </div>
<div><br></div><div><div>oamin@arizona:~/exp-caidatopo-nfd/scripts$ ping memphis</div><div>PING memphis-lan0 (10.1.1.5) 56(84) bytes of data.</div><div>64 bytes from memphis-lan0 (10.1.1.5): icmp_req=1 ttl=64 time=65.7 ms</div>
<div>64 bytes from memphis-lan0 (10.1.1.5): icmp_req=2 ttl=64 time=64.8 ms</div><div>64 bytes from memphis-lan0 (10.1.1.5): icmp_req=3 ttl=64 time=65.4 ms</div><div>64 bytes from memphis-lan0 (10.1.1.5): icmp_req=4 ttl=64 time=67.6 ms</div>
<div>64 bytes from memphis-lan0 (10.1.1.5): icmp_req=5 ttl=64 time=67.9 ms</div><div>64 bytes from memphis-lan0 (10.1.1.5): icmp_req=6 ttl=64 time=69.0 ms</div></div><div><br></div><div><div>oamin@arizona:~/exp-caidatopo-nfd/scripts$ ndnping /ndn/memphis/name1</div>
<div><br></div><div>=== Pinging /ndn/memphis/name1 ===</div><div><br></div><div>Content From /ndn/memphis/name1 - Ping Reference = 1260650668 <span style="white-space:pre-wrap"> </span>- Round Trip Time = 232.614 ms</div>
<div>Content From /ndn/memphis/name1 - Ping Reference = 1260650669 <span style="white-space:pre-wrap"> </span>- Round Trip Time = 150.735 ms</div><div>Content From /ndn/memphis/name1 - Ping Reference = 1260650670 <span style="white-space:pre-wrap"> </span>- Round Trip Time = 151.064 ms</div>
<div>Content From /ndn/memphis/name1 - Ping Reference = 1260650671 <span style="white-space:pre-wrap"> </span>- Round Trip Time = 147.209 ms</div><div>Content From /ndn/memphis/name1 - Ping Reference = 1260650672 <span style="white-space:pre-wrap"> </span>- Round Trip Time = 151.125 ms</div>
<div>Content From /ndn/memphis/name1 - Ping Reference = 1260650673 <span style="white-space:pre-wrap"> </span>- Round Trip Time = 161.333 ms</div><div><br></div></div><div>I checked the logs and it looks like sometime ndnpingserver after receiving an Interest takes much time to generate a response back.</div>
<div><br></div><div>Secondly, the RTT in ndnping seems to have high variance. For e.g. look at the 1st and 4th packet. </div><div><br></div><div>Any idea what's going on here? @John, are you experiencing the same?</div>
<div><br></div><div>Regards, </div><span class=""><font color="#888888"><div>Obaid</div></font></span></div>
</blockquote></div><br></div></div></div>