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<div class="" style="word-wrap:break-word">Hi all,
<div class=""><br class="">
</div>
<div class="">I’ve been testing <a href="https://github.com/remap/ndnrtc/tree/issues/2283-retransmissions" class=""></a><a href="https://github.com/remap/ndnrtc/tree/issues/2283-retransmissions" class="">N</a>DN-RTC with new consumer algorithm and exploring
the problem of rebufferings on consumer side (a state, when consumer is not getting data for some amount of time, flushes everything and starts over again). Consumer rebufferings are perceived as audio/video interruptions for 1-1.5sec by the user and decrease
overall user experience.</div>
<div class=""><br class="">
</div>
<div class="">I'll appreciate your insights on the analysis of the logs I retrieved from NFD.</div>
<div class=""><br class="">
</div>
<div class=""><u class="">Setup:</u></div>
<div class=""><br class="">
</div>
<div class="">[Consumer] <—> [<b class="">NFD1</b>] <==<i class="">WiFi_link</i>==> [<b class="">NFD2</b>] <==<i class="">Ethernet_link</i>==> [<b class="">NFD3</b>] <—> [Producer]</div>
<div class=""><br class="">
</div>
<div class=""><u class="">Case:</u></div>
<div class="">According to my logs, consumer starved for data after 2656 segment has arrived, so I tracked interests and data for
<b class="">2657</b> segment. According to my logs, consumer eventually received this data but too late and rebuffering was already inevitable.</div>
<div class=""><br class="">
</div>
<div class=""><b class="">NFD1 log:</b></div>
<div class="">
<div class=""><u class=""><i class="">initial interest:</i><span class="x_Apple-tab-span" style="white-space:pre">
</span></u><span class="x_Apple-tab-span" style="white-space:pre"></span>1421288806.271931 DEBUG: [Forwarder] onIncomingInterest face=266 interest=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00</div>
<div class=""><span class="x_Apple-tab-span" style="white-space:pre"></span>1421288806.272215 DEBUG: [Forwarder] onOutgoingInterest face=262 interest=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00</div>
<div class=""><span class="x_Apple-tab-span" style="white-space:pre"></span>1421288806.272469 DEBUG: [BestRouteStrategy2] /ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00?ndn.MustBeFresh=1&ndn.InterestLifetime=5000&ndn.Nonce=108889115
from=266 newPitEntry-to=262</div>
<div class=""><b class=""><span class="x_Apple-tab-span" style="white-space:pre"></span>^ 270ms</b></div>
<div class=""><i class=""><u class="">retransmission:</u></i><span class="x_Apple-tab-span" style="white-space:pre">
</span>1421288806.542289 DEBUG: [Forwarder] onIncomingInterest face=266 interest=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00</div>
<div class=""><span class="x_Apple-tab-span" style="white-space:pre"></span>1421288806.542697 DEBUG: [Forwarder] onOutgoingInterest face=262 interest=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00</div>
<div class=""><span class="x_Apple-tab-span" style="white-space:pre"></span>1421288806.543032 DEBUG: [BestRouteStrategy2] /ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00?ndn.MustBeFresh=1&ndn.InterestLifetime=5000&ndn.Nonce=562292066
from=266 retransmit-retry-to=262</div>
<div class=""><span class="x_Apple-tab-span" style="white-space:pre"></span><b class="">^ 286ms</b></div>
<div class=""><i class=""><u class="">data arrives:</u></i><span class="x_Apple-tab-span" style="white-space:pre"><i class=""><u class="">
</u></i></span>1421288806.829462 DEBUG: [Forwarder] onIncomingData face=262 data=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00/1/2749/91/0</div>
<div class=""><span class="x_Apple-tab-span" style="white-space:pre"></span>1421288806.829818 DEBUG: [Forwarder] onIncomingData matching=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00</div>
<div class=""><span class="x_Apple-tab-span" style="white-space:pre"></span>1421288806.830042 DEBUG: [Strategy] beforeSatisfyPendingInterest pitEntry=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00 inFace=262 data=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00/1/2749/91/0</div>
<div class=""><span class="x_Apple-tab-span" style="white-space:pre"></span>1421288806.830449 DEBUG: [Forwarder] onOutgoingData face=266 data=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00/1/2749/91/0</div>
<div class="" style="font-weight:bold"><br class="">
</div>
<div class=""><b class="">NFD2 log:</b></div>
<div class="">
<div class=""><i class=""><u class="">initial interest:</u></i><span class="x_Apple-tab-span" style="white-space:pre"><u class="">
</u></span>1421288806.015075 DEBUG: [Forwarder] onIncomingInterest face=266 interest=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00</div>
<div class=""><span class="x_Apple-tab-span" style="white-space:pre"></span>1421288806.015845 DEBUG: [Forwarder] onOutgoingInterest face=264 interest=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00</div>
<div class=""><span class="x_Apple-tab-span" style="white-space:pre"></span>1421288806.016255 DEBUG: [BestRouteStrategy2] /ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00?ndn.MustBeFresh=1&ndn.InterestLifetime=5000&ndn.Nonce=108889115
from=266 newPitEntry-to=264</div>
<div class=""><span class="x_Apple-tab-span" style="white-space:pre"></span><b class="">^ 545ms</b></div>
<div class=""><i class=""><u class="">retransmission:</u></i><span class="x_Apple-tab-span" style="white-space:pre">
</span>1421288806.561516 DEBUG: [Forwarder] onIncomingInterest face=266 interest=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00</div>
<div class=""><span class="x_Apple-tab-span" style="white-space:pre"></span>1421288806.562233 DEBUG: [Forwarder] onOutgoingInterest face=264 interest=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00</div>
<div class=""><span class="x_Apple-tab-span" style="white-space:pre"></span>1421288806.562626 DEBUG: [BestRouteStrategy2] /ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00?ndn.MustBeFresh=1&ndn.InterestLifetime=5000&ndn.Nonce=562292066
from=266 retransmit-retry-to=264</div>
<div class=""><span class="x_Apple-tab-span" style="white-space:pre"></span><b class="">^ 2ms</b></div>
<div class=""><i class=""><u class="">data arrives:</u></i><span class="x_Apple-tab-span" style="white-space:pre">
</span>1421288806.564828 DEBUG: [Forwarder] onIncomingData face=264 data=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00/1/2749/91/0</div>
<div class=""><span class="x_Apple-tab-span" style="white-space:pre"></span>1421288806.565282 DEBUG: [Forwarder] onIncomingData matching=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00</div>
<div class=""><span class="x_Apple-tab-span" style="white-space:pre"></span>1421288806.565594 DEBUG: [Strategy] beforeSatisfyPendingInterest pitEntry=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00 inFace=264 data=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00/1/2749/91/0</div>
<div class=""><span class="x_Apple-tab-span" style="white-space:pre"></span>1421288806.566213 DEBUG: [Forwarder] onOutgoingData face=266 data=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00/1/2749/91/0</div>
<div class=""><span class="x_Apple-tab-span" style="white-space:pre"></span><b class="">^ 13ms</b></div>
<div class=""><i class=""><u class="">data arrives 2:*</u></i><span class="x_Apple-tab-span" style="white-space:pre">
</span>1421288806.579547 DEBUG: [Forwarder] onIncomingData face=264 data=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00/1/2749/91/0</div>
<div class=""><span class="x_Apple-tab-span" style="white-space:pre"></span>1421288806.579915 DEBUG: [Forwarder] onIncomingData matching=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00</div>
<div class=""><span class="x_Apple-tab-span" style="white-space:pre"></span>1421288806.580162 DEBUG: [Strategy] beforeSatisfyPendingInterest pitEntry=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00 inFace=264 data=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00/1/2749/91/0</div>
</div>
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</div>
<div class=""><b class="">*NOTE:</b> <i class="">no data was forwarded</i></div>
<div class=""><br class="">
</div>
<div class=""><br class="">
</div>
<div class=""><b class="">NFD3 log:</b></div>
<div class="">
<div class=""><u class=""><i class="">initial interest:</i></u><span class="x_Apple-tab-span" style="white-space:pre">
</span>1421288806.249712 DEBUG: [Forwarder] onIncomingInterest face=266 interest=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00</div>
<div class=""><span class="x_Apple-tab-span" style="white-space:pre"></span>1421288806.250177 DEBUG: [Forwarder] onOutgoingInterest face=269 interest=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00</div>
<div class=""><span class="x_Apple-tab-span" style="white-space:pre"></span>1421288806.250573 DEBUG: [BestRouteStrategy2] /ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00?ndn.MustBeFresh=1&ndn.InterestLifetime=5000&ndn.Nonce=108889115
from=266 newPitEntry-to=269</div>
<div class=""><span class="x_Apple-tab-span" style="white-space:pre"></span><b class="">^271ms</b></div>
<div class=""><u class=""><i class="">data generated:</i></u><span class="x_Apple-tab-span" style="white-space:pre">
</span>1421288806.521982 DEBUG: [Forwarder] onIncomingData face=269 data=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00/1/2749/91/0</div>
<div class=""><span class="x_Apple-tab-span" style="white-space:pre"></span>1421288806.522531 DEBUG: [Forwarder] onIncomingData matching=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00</div>
<div class=""><span class="x_Apple-tab-span" style="white-space:pre"></span>1421288806.522844 DEBUG: [Strategy] beforeSatisfyPendingInterest pitEntry=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00 inFace=269 data=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00/1/2749/91/0</div>
<div class=""><span class="x_Apple-tab-span" style="white-space:pre"></span>1421288806.523363 DEBUG: [Forwarder] onOutgoingData face=266 data=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00/1/2749/91/0</div>
<div class=""><span class="x_Apple-tab-span" style="white-space:pre"></span><b class="">^273ms</b></div>
<div class=""><u class=""><i class="">retransmission:</i></u><span class="x_Apple-tab-span" style="white-space:pre">
</span>1421288806.796022 DEBUG: [Forwarder] onIncomingInterest face=266 interest=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00</div>
<div class=""><span class="x_Apple-tab-span" style="white-space:pre"></span>1421288806.796418 DEBUG: [Forwarder] onOutgoingData face=266 data=/ndn/edu/ucla/remap/ndnrtc/user/remap/streams/camera/low/delta/2657/data/%00%00/1/2749/91/0</div>
</div>
<div class=""><br class="">
</div>
<div class=""><br class="">
</div>
<div class=""><br class="">
</div>
<div class="">There are several questions arise:</div>
<div class="">1. Why do you think the delay b/w initial interest and retransmission for the NFD2 became 545ms (compared to 270ms with NFD1)? Could it be WiFi fault?</div>
<div class="">2. How come the delay b/w initial interest and data in NFD3 is 271ms and NFD3 forwards this data to NFD2, but NFD2 didn’t get this data and instead got retransmission interest after another 545-271=<b class="">274ms
</b>and later got the same data with 13ms difference? Could it be unreliable logging in NFD?</div>
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</div>
<div class="">I attached full NFD logs to this message.</div>
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</div>
<div class="">Thank you in advance.</div>
<div class="">All ideas and thoughts are welcome. </div>
<div class=""><br class="">
</div>
<div class="">Thanks,</div>
<div class=""><br class="">
</div>
<div class="">PS. Basically, such things block deployment of NDN-RTC (NdnCon) for the community as it delivers low-quality user experience (i.e. videoconference with interruptions =( ), so I really hope for the help and feedback.</div>
<div class=""><br class="">
</div>
<div class=""></div>
</div>
</div>
<div class="" style="word-wrap:break-word">
<div class="">
<div class=""></div>
<div class=""><br class="">
<div class="">-- <br class="">
Peter Gusev<br class="">
<a href="mailto:peter@remap.ucla.edu" class="">peter@remap.ucla.edu</a><br class="">
+1 213 5872748 (USA)<br class="">
+7 916 4434826 (Russia)<br class="">
+37 259 226448 (in case any other number is unavailable)<br class="">
peetonn_ (skype) </div>
<br class="">
</div>
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