Timing Analysis of Data Packets in a Reconfigurable Distributed System using a Software-in-Loop Simulation

Abstract

Simulation is one of the most common methods used to test the time bounds in a system. This helps in verifying the extent of the factors like extensive delays and faults that may affect the intended results. During simulation, these factors can be manually triggered in order to see the extent of the impact on the system due to change in the factors. This can be used so that the system can be prepared by handling or avoiding the possible failures. This work emphasizes on analyzing end-to-end delays in a network model by using a PingPong application running over the middleware ScOSA. ScOSA is an ongoing project in DLR, designed to run on on-board computers connected in a distributed network aiming at a well distributed workload and a higher reliability. The network layout of the system along with routers is simulated on a model designed using the simulation tool OMNeT++. To emulate the delays caused by wormhole routing, a delay model is integrated with the virtual network that makes sure that a packet is forwarded only when the transmission channel is free. The complete traffic is captured and analyzed for minimum, maximum and mean end-to-end delays in different virtual networks. One of the important feature of ScOSA is the reconfiguration of the system when a node fails. The work also demonstrate how the reconfiguration time increases as the network scales.