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, looking specifically at a high-level telecommunications network modeling language called TeD. TeD is built upon an underlying Time Warp mechanism which will serve as an example of an optimistic approach to PDES. We will then examine a model, built using TeD, which simulates networks that use the TCP/IP protocol. We will see how this model exposes some of the characteristics of PDES, in addition to looking at some of the details encountered when implementing TCP/IP.