How Flight Sims Deal With Lag

mnemonic writes "How are hundreds of air, ground and sea units simulated in a multiplayer flight simulation with high fidelity, all the while maintaining a smooth framerate for dialup users? Two network protocols, a hybrid server-client peer to peer architecture (the latter of which is reportedly used by Doom 3) are only some of what it takes to keep Falcon 4.0, a beast of a game, playable online."