[1] The simulator contains several models for structured (e.g. Chord, Kademlia, Pastry) and unstructured (e.g. GIA) peer-to-peer protocols.

Module behavior can easily be customized by specify parameters in a human readable configuration file.

In order to validate and debug new or existing overlay protocols you can make use of the GUI of OMNeT++, which visualizes networks topologies, messages and node state variables like the routing table.

OverSim has a flexible underlying network scheme, which on the one hand provides a fully configurable network topology with realistic bandwidths, packet delays, and packet losses (INETUnderlay), and on the other hand a fast and simple alternative model for high simulation performance (SimpleUnderlay).

Therefore, the simulation framework is able to handle and assemble real network packets and to communicate with other implementations of the same overlay protocol.