The event-driven simulator.
A good point to start browsing is {@link peersim.edsim.EDSimulator}.
Class {@link peersim.edsim.CDScheduler} is also interesting as it represents
a bridge between package {@link peersim.cdsim} and this package.
Finally, check out {@link peersim.transport} too as it is very
useful for defining the transport layer, that defines delays, omissions, etc.