Evaluating LAN communications performance for a real-time environment

The Navy is a large user of real time systems. A modern surface ship is deployed with hundreds of computers which are required for the ship to perform its mission. The Navy is moving away from using "niche" market components to meet its real time computing needs and towards distributed processing using Commercial Off The Shelf (COTS) computing components. The use of commercial real time computing components requires careful evaluation to determine if they can meet the real time requirements. The paper focuses on evaluating the communication resources for use aboard a Navy ship. Presented are: key performance metrics for assessing the communication capabilities of computers for use aboard Navy ships; an assessment of existing methods for determining these metrics; a methodology for collecting data to evaluate a particular component's performance related to these; and examples of applying the methodology.