OverSim Usage

First steps with OverSim:

• change into directory OverSim-20101103/simulations

• start OverSim by typing

  ../src/OverSim
  

• choose a simulation scenario (e.g. Chord)

• press the Run button in OMNeT++'s main window

• ... watch & enjoy ...

• press the Stop button to pause simulation

• end OverSim by closing OMNeT++'s main window
  (press Yes to invoke finish()-method call in all OMNeT++ modules)

• If you want to simulate large networks like the predefined simulation scenario ChordLarge invoke OverSim without GUI:

  ../src/OverSim -uCmdenv -cChordLarge
  

• The simulation results get stored in the simulations/results directory. Use the supplied python scripts or the Eclipse IDE for postprocessing.

Editing parameters:

• Edit simulations/omnetpp.ini to change or define new simulation scenarios
  (default parameters are stored in simulations/default.ini, parameters are described on the OverSimAPI pages)
• Make use of the OMNeT++ ini file syntax for easy parameter studies. This is an example for a study on Chord with different churn rates, two different stabilize intervals and 5 different seeds. Simply add this section to simulations/omnetpp.ini:

  repeat = 5
  *.underlayConfigurator.churnGeneratorTypes = "oversim.common.LifetimeChurn"
  **.overlayType = "oversim.overlay.chord.ChordModules"
  **.tier1Type = "oversim.applications.kbrtestapp.KBRTestAppModules"
  **.targetOverlayTerminalNum = 100
  **.initPhaseCreationInterval = 0.1s
  **.measurementTime = 500s
  **.transitionTime = 100s 
  **.overlay.chord.stabilizeDelay = ${stab=5, 60}s
  **.lifetimeMean = ${lifetime=1000, 2000, 10000}s
  

• Run this parameter study:

  ../src/OverSim -cChordChurn -uCmdenv
  

Use the post-processing scripts to generate plots

• Install python (with matplotlib, numpy and scipy) and gnuplot.
  • On Ubuntu:

    sudo apt-get install python-matplotlib python-scipy gnuplot
    

  • On Windows:
    • Install the ​python(x,y) light edition, which contains all needed packages.
• View the results with 95% confidence intervals by using the script simulation/tools/plot.py:

  tools/plot.py -c0.95 lifetime "KBRTestApp: One-way Delivery Ratio.mean" results/ChordChurn-*.sca
  

• To generate gnuplot output append -o chord_churn to the script parameters. This will generate chord_churn.plot and chord_churn.dat files, which can be used as input to gnuplot. Call gnuplot like this to generate a publication quality chord_churn.eps plot:

  gnuplot chord_churn.plot
  

• To plot a vector file (e.g. the routing latency) use the simulations/tools/vecplot.py script. The following creates a plot with 95% confidence intervals aggregating all vectors in buckets of 60 seconds:

  tools/vecplot.py -b 60 -c0.95 -i"lifetime=1000\""  "KBRTestApp: One-way Latency" results/ChordChurn-*.vec
  

Tips for using the Eclipse IDE

• Start the IDE with omnetpp

• To start simulations from Eclipse, select OverSim in the project explorer,
  click on Run simulations and select simulations/omnetpp.ini

• To view simulation results, use the project explorer and double click
  on a .sca file in the simulations/results directory

• Set the OverSim coding style in Preferences by importing
  the style from doc/EclipseOverSimCodeStyle.xml