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Setup a simple simulation: Summary

Let us summarize what we have until now. We set up our very first simulation, which consists of a single node. It is essential to understand the underlying structure, visualized here:

omnetpp_overview_code.png

Each simple module in OMNeT++ consists of three parts (files): CC, H and NED. Two files are essential to setup a simulation: the network NED and the parameter setup omnetpp.ini

Note the following things:

  1. Each simple module in OMNeT++ consists of three parts (I like calling them the OMNeT trinity): an NED file, which defines the external and internal structure of the module (mostly parameters and interfaces/gates), and H and CC files, that determine the behavior of this module. While it is possible to put those parts in other files, I would STRONGLY encourage you to keep them separate and nicely named as the module itself.
  2. The network NED file defines the structure of the complete network. We can also put layers in between (compound modules), but this is an advanced topic. It pretty much says which modules to use and how to connect them, given their interfaces/gates.
  3. The omnetpp.ini is the last required file, which defines which network to run, for how long, etc., and sets the parameter values of all involved modules.

By now, you have also figured out that the NED language is something unique to OMNeT++. It is derived from C++ and is used only to describe the structure of the modules so that the kernel can construct them automatically. The NED language has developed dramatically over the years and has become a very powerful tool. In this tutorial, we will use mostly basic stuff, but you can find more information about it here.

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