Abstract
Discrete event simulation (DES) entails modeling a system whose state changes only at discrete points in simulated time. Parallelizing such a simulation introduces many interesting problems, particularly in synchronization.

We will summarize the main issues involved when implementing such a parallel simulation, and compare and contrast the conservative and optimistic approaches to synchronization, looking at examples of each. We'll also see two examples of high-level telecommunication network modeling languages, each built on top of a different underlying simulation mechanism. Finally, we'll briefly discuss models of TCP/IP and BGP which were implemented in those languages.