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The simulation time of parallel and distributed discrete event simulation is the heart rate for as-fast-as execution schemes. Agreeing upon a global simulation time and distributing it to the simulation processes can be improved by exploiting or redesigning the network hardware. In this paper, we present such an approach that offloads simulation time calculations to network switches in order to speed up the steps where time advance requests are made and time advance grants are waited. By reducing the waiting time for time advancement, we aim to improve the overall performance of the parallel simulations. The measurements from the FPGA-based hardware setup and the results from our network simulations show that overall performance can be improved when time management calculations are offloaded to the network switches. Additionally, the transient message problem is also solved within the network by not allowing the time control messages to bypass the time-dependent events. The network acceleration of the region-based event distribution is also studied, and offloading the region matching tasks to the network switches is found to be feasible to reduce the costs of node-based calculations, especially for fast-moving regions. In this study, we consider High Level Architecture (HLA) for simulation infrastructure and fat tree topology for high-performance networking. [ABSTRACT FROM AUTHOR]

Collective Communication Algorithms for 2D torus networks have been investigated quite extensively in the literature and two broad approaches, namely direct methods and indirect (message combining) methods are recognized in the field. While direct methods minimize the volume of data, the indirect methods reduce the number of message start-ups. Consequently, either a suite of algorithms must be employed for efficiency over a wide range of message lengths and communication operations or algorithms should be able to adapt themselves to the current case, possibly by switching between direct and indirect routing modes as appropriate. In this paper, we propose adaptive routing algorithms for all-port, wormhole routed, synchronous, 2D torus networks optimized for one-to-all broadcast, gossiping and complete exchange collective communication operations. The proposed algorithms employ completely-connected subnetworks where complete exchange amongst the nodes in the subnetwork can be accomplished in one step only. Combined with suitable 2D plane tiling techniques, the proposed algorithms share the same set of primitive operations and yield superior performance compared to previously proposed methods, either pure or hybridized. [ABSTRACT FROM AUTHOR]