Re: [Cse461] packet loss in emulator and simulator

From: Janet Davis (jlnd_at_cs.washington.edu)
Date: Mon Feb 23 2004 - 11:01:06 PST

  • Next message: Eileen Hash: "Re: [Cse461] packet loss in emulator and simulator"

    Sorry to everyone who's suffered from this. We won't deduct points for
    subtle bugs in your retransmission algorithm if the overall design is
    correct.

    To enable packet loss in the simulator, make the following change at line
    89 of commands.rb:

        # lossRate = $1.to_f if opts =~ /lossRate:\s*([0-9\.]+(:?[eE]\d*)?)/
        lossRate = 0.05

    Cheers,
    Janet

    On Sun, 22 Feb 2004, Janet Davis wrote:

    > On Sun, 22 Feb 2004, Matthew Burkhart wrote:
    >
    > > We were trying run our test cases for the turnin and we cannot get the
    > > simulator or emulator to produce any packet loss!
    > > We looked in the code and found that that schedulePkt(src, size, now)
    > > method in topology.rb (which causes packet loss) is not used at all in
    > > the emulator/trawler. Ok so the emulator can't do packet loss...?
    > >
    > > So we then tried the simulator it didnt work immediately, so we checked
    > > out the code and found two issues:
    > > lossRate = $1.to_f if opts =~ /lossRate:\s*([0-9\.]+(:?[eE]\d*)?)/
    > > so our topo file should use "lossRate: 0.05" instead of "loss: 0.05"?
    > > Furthermore, the $POSTMATCH use in parseEdgeOptions($POSTMATCH) is nil
    > > ONLY when we run simulator, but parses correctly in the trawler.
    > > What is going on here?? What are we missing? Have you all been able to
    > > get packet loss to work?
    >
    > Looks like we screwed up. Thanks for debugging; this should help Evan
    > straighten it out.
    >
    > > Should we just hard code the default loss rate in simulator to 0.05?
    >
    > That sounds like a fine idea.
    >
    > Cheers,
    > Janet
    >
    > --
    > Janet Davis
    > jlnd_at_cs.washington.edu
    > http://www.cs.washington.edu/homes/jlnd/
    >
    > _______________________________________________
    > Cse461 mailing list
    > Cse461_at_cs.washington.edu
    > http://mailman.cs.washington.edu/mailman/listinfo/cse461
    > 

    -- 
Janet Davis
jlnd_at_cs.washington.edu
http://www.cs.washington.edu/homes/jlnd/
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