Response time of antiparallel connections with respect to congestion - PowerPoint PPT Presentation

The problem Possible solutions A few results Conclusion Response time of antiparallel connections with respect to congestion control algorithms Tristan BRAUD Advisors: Martin HEUSSE Guillaume URVOY-KELLER May 15 st 2014 Response time of antiparallel connections with respect to congestion control algorithms 1

The problem Possible solutions A few results Conclusion A common situation: an user browsing the Internet through a DSL link Response time of antiparallel connections with respect to congestion control algorithms 2

The problem Possible solutions A few results Conclusion What often happens Response time of antiparallel connections with respect to congestion control algorithms 3

The problem Possible solutions A few results Conclusion A non exhaustive list of possible solutions In the core network: Fair queuing Smaller uplink buffers End to end TCP stack: modifying the TCP variant may affect the performances Adding more traffic? adding smaller UDP packets could virtually decrease the buffer size. Response time of antiparallel connections with respect to congestion control algorithms 4

The problem Possible solutions A few results Conclusion Combining different TCP variants on the uplink and downlink 100 Vegas Down Time to complete (s) New Reno / Cubic Up 10 NewReno/Cubic 1 Up/Down Vegas Up 10000 100000 1e+06 Size (Bytes) Response time of antiparallel connections with respect to congestion control algorithms 5

The problem Possible solutions A few results Conclusion Adding more traffic Large buffer UDP bursty With UDP Small buffer 100 100 100 100 80 80 80 80 Link utilization 60 60 60 60 % % % % 40 40 40 40 20 20 20 20 0 0 0 0 Up Down Up Down Up Down Up Down 500 500 500 500 ms ms ms ms 300 300 300 300 RTT 100 100 100 100 0 0 0 0 Up Down Up Down Up Down Up Down Response time of antiparallel connections with respect to congestion control algorithms 6

The problem Possible solutions A few results Conclusion A few viable solutions in End to end Still, modifying the core buffers remain the best solution Response time of antiparallel connections with respect to congestion control algorithms 7

The problem Possible solutions A few results Conclusion Thank you for your attention Response time of antiparallel connections with respect to congestion control algorithms 8