Pricing the Internet

Current Competitions

A competition consists of a goal, a description of the type of strategy that tries to attain the goal, and rules for scoring. In some cases we describe what sort of simulation environment the competition will be run in, and suggest some starting points for strategies.

• FileSpeed - Transfer a file within a budget as quickly as possible
• FileCost - Transfer a file in a certain time as cheaply as possible

Writing your own strategies

You can also write strategies which attempt to achieve a set goal. For each objective, there will be a corresponding Strategy class which you should inherit from.

For example, in the FileSpeed competition, the objective is to transmit a file of given size in the shortest time possible, subject to a limited budget. For this, you should inherit from FileSpeed.FileSpeedStrategy. The details are much the same as for SingleFlow.FlowControlStrategy.

public class FileSpeed.FileSpeedStrategy
  {
  double abstract updateRate(FileSpeed.MarkInfo lastMarks); // override this
  }

public class FileSpeed.MarkInfo
  {
  int getMarks(); // number of marked packets received last timestep
  int getDropped(); // estimate of number of dropped packets last timestep
  double getCost(); // getMarks()+k*getDropped(), where k is set by experimenter
  double getMoneyLeft();
  int getTransmitLeft();
  }

Testing your classes

javac MyStrategy.java

# add a line to classes.txt for each class you want loaded
MyStrategy

Standard interfaces

public class SingleFlow
  {
  public static class StreamControlStrategy
    {
    public abstract void execute(PacketList in, PacketList out); // override this
    }
  ...
  }

public class FlowControlStrategy extends SingleFlow.StreamControlStrategy
  {
  public void execute(PacketList in, PacketList out)
    // work out how many packets were dropped and marked, store in lastMarks, call updateRate
  public abstract double updateRate(MarkInfo lastMarks); // override this
  ...
  public class MarkInfo
    {
    public double getCost()
    public int getMarks()
    public int getDropped() ...
    }
  }

Simulator Architecture

Many of these classes are made up of other classes. A QueueResource is an example of a Resource, and it contains a QueueResource.QueueMarkingStrategy. When you add to the simulation a class which is made up of secondary classes, you are prompted to specify which those secondary classes should be.

Another very useful example is SingleFlow. This is a UserTemplate which also has a Route. Whenever you add a SingleFlow.FlowControlStrategy to the UserTemplate, it creates a new User made out of the Route and the FlowControlStrategy.

Editing properties

public int getQuantity();
public void setQuantity(int i);

This lets you write your own classes made up out of secondard classes. Just create a pair of methods inspecting and setting the secondary class. The only restriction is that the secondard class must have a public constructor taking no arguments.

Once the experimenter okays the parameters, if your class has a method

public void done()

Viewing Statistics

public NumbersObserved[] getObservableNumbers()

Many classes also have toString() and stateToString() methods which describe the state of an object.

Documentation