<div dir="ltr"><span style="font-size:12.8px">Hi Peter</span><div style="font-size:12.8px"><br></div><div style="font-size:12.8px">The trace is attached to <a href="https://redmine.named-data.net/issues/3642#note-12">https://redmine.named-data.net/issues/3642#note-12</a> for permanent record.</div><div style="font-size:12.8px">I can see a lot of Nack-Duplicates from the trace:</div><div style="font-size:12.8px"><div><font face="monospace, monospace">vagrant@m0212:~$ ndndump -r capture.pcap | grep -v 10.10.12.3 | sed -e 's/From: <a href="http://10.10.12.//">10.10.12.//</a>' -e 's/, To: <a href="http://10.10.12./-">10.10.12./-</a>>/' -e 's/, Tunnel Type: UDP, / /' -e 's|/ndn/edu/ucla/remap/ndnrtc/user/client1/streams/camera/low/key|()|' | grep 'Nonce=1732610923'</font></div><div><font face="monospace, monospace">1466801763.692043 4->2 INTEREST: ()/2/data/%00%00?ndn.MustBeFresh=1&ndn.InterestLifetime=3000&ndn.Nonce=1732610923</font></div><div><font face="monospace, monospace">1466801763.706693 7->2 INTEREST: ()/2/data/%00%00?ndn.MustBeFresh=1&ndn.InterestLifetime=3000&ndn.Nonce=1732610923</font></div><div><font face="monospace, monospace">1466801763.706810 2->7 NACK: Duplicate, ()/2/data/%00%00?ndn.MustBeFresh=1&ndn.InterestLifetime=3000&ndn.Nonce=1732610923</font></div><div><font face="monospace, monospace">1466801763.732589 6->2 INTEREST: ()/2/data/%00%00?ndn.MustBeFresh=1&ndn.InterestLifetime=3000&ndn.Nonce=1732610923</font></div><div><font face="monospace, monospace">1466801763.732702 2->6 NACK: Duplicate, ()/2/data/%00%00?ndn.MustBeFresh=1&ndn.InterestLifetime=3000&ndn.Nonce=1732610923</font></div><div><font face="monospace, monospace">1466801763.822424 12->2 INTEREST: ()/2/data/%00%00?ndn.MustBeFresh=1&ndn.InterestLifetime=3000&ndn.Nonce=1732610923</font></div><div><font face="monospace, monospace">1466801763.822546 2->12 NACK: Duplicate, ()/2/data/%00%00?ndn.MustBeFresh=1&ndn.InterestLifetime=3000&ndn.Nonce=1732610923</font></div><div><font face="monospace, monospace">1466801763.825780 9->2 INTEREST: ()/2/data/%00%00?ndn.MustBeFresh=1&ndn.InterestLifetime=3000&ndn.Nonce=1732610923</font></div><div><font face="monospace, monospace">1466801763.825867 2->9 NACK: Duplicate, ()/2/data/%00%00?ndn.MustBeFresh=1&ndn.InterestLifetime=3000&ndn.Nonce=1732610923</font></div><div><font face="monospace, monospace">1466801763.838540 10->2 INTEREST: ()/2/data/%00%00?ndn.MustBeFresh=1&ndn.InterestLifetime=3000&ndn.Nonce=1732610923</font></div><div><font face="monospace, monospace">1466801763.838657 2->10 NACK: Duplicate, ()/2/data/%00%00?ndn.MustBeFresh=1&ndn.InterestLifetime=3000&ndn.Nonce=1732610923</font></div><div><font face="monospace, monospace">1466801763.854087 5->2 INTEREST: ()/2/data/%00%00?ndn.MustBeFresh=1&ndn.InterestLifetime=3000&ndn.Nonce=1732610923</font></div><div><font face="monospace, monospace">1466801763.854200 2->5 NACK: Duplicate, ()/2/data/%00%00?ndn.MustBeFresh=1&ndn.InterestLifetime=3000&ndn.Nonce=1732610923</font></div><div><font face="monospace, monospace">1466801763.934206 11->2 INTEREST: ()/2/data/%00%00?ndn.MustBeFresh=1&ndn.InterestLifetime=3000&ndn.Nonce=1732610923</font></div><div><font face="monospace, monospace">1466801763.934301 2->11 NACK: Duplicate, ()/2/data/%00%00?ndn.MustBeFresh=1&ndn.InterestLifetime=3000&ndn.Nonce=1732610923</font></div><div><font face="monospace, monospace">1466801764.041182 8->2 INTEREST: ()/2/data/%00%00?ndn.MustBeFresh=1&ndn.InterestLifetime=3000&ndn.Nonce=1732610923</font></div><div><font face="monospace, monospace">1466801764.041306 2->8 NACK: Duplicate, ()/2/data/%00%00?ndn.MustBeFresh=1&ndn.InterestLifetime=3000&ndn.Nonce=1732610923</font></div><div><font face="monospace, monospace">1466801764.154624 13->2 INTEREST: ()/2/data/%00%00?ndn.MustBeFresh=1&ndn.InterestLifetime=3000&ndn.Nonce=1732610923</font></div><div><font face="monospace, monospace">1466801764.154732 2->13 NACK: Duplicate, ()/2/data/%00%00?ndn.MustBeFresh=1&ndn.InterestLifetime=3000&ndn.Nonce=1732610923</font></div></div><div style="font-size:12.8px"><br></div><div style="font-size:12.8px">Protocol <a href="http://named-data.net/doc/ndn-tlv/interest.html#nonce" target="_blank">requires Name+Nonce combination to be unique</a>, but the same Nonce is being used by consumer 4,7,6,12,9,10,5,11,8,13. As a result, all except consumer 4 will not get Data.</div><div style="font-size:12.8px">Even if consumer 4 gets Data this time, if other consumers are still generating the same stream of Nonces, the next Interest from consumer 4 may arrive later than the duplicate Interest from other consumers, causing consumer 4 to receive a Nack-Duplicate and therefore lose track of the video stream.</div><div style="font-size:12.8px"><br></div><div style="font-size:12.8px">This is either a bug in the library, or you are using the library incorrectly. You may get more help on ndn-lib mailing list.<br></div><div style="font-size:12.8px"><br></div><div style="font-size:12.8px">Yours, Junxiao</div><div class="gmail_extra"><br><div class="gmail_quote">On Fri, Jun 24, 2016 at 2:16 PM, Gusev, Peter <span dir="ltr"><<a href="mailto:peter@remap.ucla.edu" target="_blank">peter@remap.ucla.edu</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex">
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<div>What I meant is that all consumers start simultaneously and what I repeatedly observe, is that they are unable to catch up with the latest produced data in a synchronous manner, what is expected. Instead, chasing phase resolution happens one (or
few) consumer(s) at a time. Consumers are identical and in the beginning express same interest - with rightmost child selector enabled. </div>
<div><a href="http://ec2-52-90-158-238.compute-1.amazonaws.com:3000/dashboard/db/ndn-rtc-test-real-time-metrics?panelId=4&fullscreen&from=1466801762500&to=1466801788564" target="_blank">Here </a> (login/pw: guest/ndnguest) you can see “rebufferings stairs”
- which indicate that consumer was not able to get any data, so it started over. It feels like NFD was answering one consumer (rightmost interest) at a time.</div>
<div><br>
</div>
<div>I attached pcap file for the first 1-1.5 minute of test.</div>
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<div><div class="h5"><div><blockquote type="cite"><div><div dir="ltr"><div><div class="gmail_extra"><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div style="word-wrap:break-word"><div><br>
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<div>I ran more 1-to-10 tests recently (here are <a href="http://ec2-52-90-158-238.compute-1.amazonaws.com:3000/dashboard/db/ndn-rtc-tests-test-run-overview?from=1466566688346&to=1466567022507&var-runtime=15m" target="_blank">the results</a> of
one out five tests) and observe an unusual behavior: consumers are not able to get data all simultaneously, instead - they join one-by-one. This can be seen from <a href="http://ec2-52-90-158-238.compute-1.amazonaws.com:3000/dashboard/db/ndn-rtc-tests-test-run-overview?from=1466566688346&to=1466567022507&var-runtime=15m&panelId=15&fullscreen" target="_blank">rebufferings
graph</a> and <a href="http://ec2-52-90-158-238.compute-1.amazonaws.com:3000/dashboard/db/ndn-rtc-tests-test-run-overview?from=1466566688346&to=1466567022507&panelId=20&fullscreen&var-runtime=15m" target="_blank">incoming traffic graph</a>. I see
that, consumers get timeouts for the initial interests.</div>
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</div>
</div></blockquote></div></div></div></div></div></blockquote></div></div></div></div></div></blockquote></div><br></div></div>