As AWIPS continues to grow and expand to meet the ever-increasing need for more information, one of the toughest things to predict is when and where the increased data flow will impact communication and infrastructure. At what point do servers need to be upgraded? When should the National Weather Service (NWS) plan to increase the capacity of the AWIPS wide area network (WAN) and which links must be increased? In order to address these questions, Northrop Grumman Information Technology developed a network simulation model for the NWS. The model allows AWIPS planners to simulate various “what-if” scenarios to study the impact of proposed changes. This paper will provide a glimpse behind the development of the ACNM. It will discuss how the model addresses three very specific applications: the central collection of WSR-88D Level II and Level III archive data, distribution of the Eta model at 12 Km resolution, and the central collection of the fully deployed NWS Digital Forecast Database (NDFD).