> On Mar 24, 2019, at 9:55 AM, Dave Taht <[email protected]> wrote: > > 1) The research into whether bit flipping to the extent that SCE will > do has not been done yet. The study of ECT(0) vs ECT(1) behavior > transiting to CE was a little lightweight. > > To test this we going to fire up a ton of nanodes in various data > centers, with low SCE thresholds, and low bandwidths, to flip lots of > bits, and test between the data centers and from as many vantage > points around the net as we can get - do packet captures as well as > flent tests > > as a control, set up identical boxes, with SCE disabled, in the same > data centers. > > Setup flent, irtt, iperf3.
Sounds good, I’ll offer my home setup with a couple APU2s as a “residential WISP” vantage point. I was unable to access it with OpenVPN from the boat but I’ll sort that out before I go. > 2) Diffserv bit preservation test > > The research going by on the tsvwg mailing seems a bit dated. It is > very straightforward to use irtt to test to see what udp codepoints > survive e2e, and to also leverage this testbed setup. Similarly, > netperf can easily be used to mark tcp. We do not have a good packet > cap tool to verify that the bits are being set right, however I think > irtt can be modified to check for correctness here and produce a > report. The irtt server knows what codepoint was negotiated and could easily emit a log message if incoming packets don’t match, but unfortunately the codepoint of incoming packets is not available without using a raw conn (requires root). We’ll want that anyway for UDP lite and I’ll see what’s possible tonight, but for now we can also just use a simple tcpdump filter like this: tcpdump -r file.pcap udp port 2112 and greater 80 and "ip[1] != 0x1” “greater 80” ignores the handshake packets and 0x1 is whatever TOS value we want to make sure the packets contain. We can use different filters for other traffic. > On Sun, Mar 24, 2019 at 1:45 AM Jonathan Morton <[email protected]> wrote: >> >>> On 24 Mar, 2019, at 8:37 am, Pete Heist <[email protected]> wrote: >>> >>> I should theoretically arrive at the boat today some time after 3pm, having >>> picked up a mini HDMI to HDMI adapter, which we can use with the cable >>> that’s there… >> >> Awesome. I'm also setting up a Linux VM on my Mac, which should help things >> along. >> >> We're bringing up some actual hardware with the SCE-enabled Cake on it now. >> Dave wants to investigate various theoretical phenomena the Internet might >> exhibit with a mixture of ECN codepoints; I just want to be sure it actually >> works as intended, before I move on to fiddling with TCP. >> >> - Jonathan Morton >> >> _______________________________________________ >> Cake mailing list >> [email protected] >> https://lists.bufferbloat.net/listinfo/cake > > > > -- > > Dave Täht > CTO, TekLibre, LLC > http://www.teklibre.com > Tel: 1-831-205-9740 _______________________________________________ Cake mailing list [email protected] https://lists.bufferbloat.net/listinfo/cake
