The interconnection network plays an important role in the technological revolution brought by exascale and big-data challenges to high-performance computing (HPC) systems and datacenters. In these systems, the number of processing and storage nodes is growing significantly to meet the higher-computing power and storage demands. Therefore, the interconnection network of these systems must provide low latency and high-communication bandwidth; otherwise, it would become the bottleneck of the entire system. In addition, the power consumption of these systems should not increase significantly with respect to current values; otherwise, the cost of these systems in terms of power consumption would be excessive. Therefore, the interconnection network of these systems must provide the required high performance while reducing as much as possible its power consumption. To face these challenges, there are several design activities that should be considered: network topology and connectivity, routing algorithm, reliability and fault tol- propose a queuing scheme where queues are used both to reduce the head-of-line blocking and to prevent deadlocks. Next, they extend this scheme to provide also differentiated services to HPC applications. Finally, Sawabe et al 5 propose new packet-chunking schemes aimed at both meeting application requirements and improving router throughput, which achieve excellent performance in reducing the number of small outgoing packets from the router while meeting various delay requirements.In our opinion, both the scope and the high-technical quality of these papers make them very relevant for anyone involved, or just interested, in the exascale and big-data challenges, especially from the point of view of high-performance interconnection networks.
LIST OF REVIEWERSWe would like to thank the following reviewers for their support assessing the submitted papers to this Special Issue. Their reviews and discussions provided invaluable help for the guest editors' final decision.