Corson, M. ScottThe following report describes the facilities, personnel, and simulation effort underway in the Communications and Signal Processing Laboratory (CSPL) of the Systems Research Center (SRC). The intent of the effort is to create a useful simulation and modeling environment to aid in the performance analysis of communication systems. In particular, we describe a distributed network simulation testbed under development to allow rapid prototyping and performance evaluation of distributed network communication protocols. The testbed's design is modular thus allowing it to be built in a piecemeal fashion with each sub- project contributing software modules to be testbed. We first describe the facilities and personnel involved in the simulation effort and then describe the current testbed status and future architecture.en-USTechnical Report