One of the most critical factors in developing Distributed Interactive Simulation (DIS) is that of defining the performance to be supplied by the network. Although the performance of a given network implementation is a scalable quantity, beyond a certain level (e.g., 1.5 Mbs) it becomes a heavy cost (and sometimes schedule) driver. The situation is further complicated by the interactive nature of DIS since each session or exercise poses a unique set of requirements. To the ability to accurately estimate those requirements in advance is a goal of the DIS community.

This paper will describe a mathematical estimating tool that is being jointly developed by Grumman and UCF/IST. A preliminary version of the tool, implemented in the form of a spreadsheet executable on either PC or Macintosh platforms, was used to estimate the network traffic prior to the DIS demonstration at the 1992 I/ITSC conference. A "post mortem" of that demonstration is included, comparing actual I/ITSC traffic to that predicted by this technique. The paper will also describe future enhancements to the tool.