YAPS = Yet Another Packet Simulator

Core stuff is in coresim/

Normally these files shouldn't change. This directory includes implementations of the following:

• Main event loop and related helper functions, global variables, main() function to determine which experiment to run: main.cpp
  • Note: deciding which experiment to run will eventually be moved to the run/ directory, probably to experiment.cpp.
• Core event implementations (Event, FlowArrivalEvent, FlowFinishedEvent, etc): event.cpp.
• Representation of the topology: node.cpp, topology.cpp
• Queueing behavior. This is a basis for extension; the default implementation is FIFO-dropTail: queue.cpp.
• Flows and packets. This is also a basis for extension; default is TCP: packet.cpp and flow.cpp.
• Random variables used in flow generation. Used as a library by the flow generation code: random_variable.cpp.

Extensions are in ext/

This is where you implement your favorite protocol.

• Generally extensions are created by subclassing one or more aspects of classes defined in coresim/.
• Once an extension is defined, it should be added to factory.cpp so it can be run.
  • Currently, factory.cpp supports changing the flow, queue, and host-scheduling implementations.
• Methods in coresim/ call the get_... methods in factory.cpp to initialize the simulation with the correct implementation.
• Which implementation to use from factory.cpp is determined by the config file, parsed by run/params.cpp.
  • You should give your extension an identifier in factory.h so it can be uniquely identified in the config file.

Stuff related to actually running the simulator is in run/

• Experiment setup, running, and post-analysis: experiment.cpp
• Flow generation models: flow_generator.cpp
• Parsing of config file: params.cpp
  • Configuration parameters for your extension should be added to params.h and params.cpp.
  • These can then be accessed with params.<your_parameter>

Helper scripts to run experiments are in py/

This can be useful if:

• You are running many experiments in parallel.
• You want to easily generate configuration files.

To compile, the Automake and Autoconf files are included: configure.ac and Makefile.am. The makefile will produce two targets: simulator and simdebug. simdebug is equivalent to simulator, except compiler optimzations are turned off to make debugging easier.

Authors

• Gautam Kumar
• Akshay Narayan
• Peter Gao