IBCube
Datacenter networks have attracted a lot of research interest in the past few years. BCube is proved to be a promising scheme due to its low cost. By using a recursive construction scheme, BCube can exponentially scale a datacenter. Industry experiences, however, articulate the importance of incremental expansion of datacenter. In this article, the authors show that BCube's expanding scheme suffers low utilization of switch ports. They propose IBCube, a novel economical design for incrementally building datacenter networks. The insight is that: by letting the number of switches in each BCube layer equal the number of the building blocks, the authors can enable the switch ports to be fully utilized to support the total number of network interface cards of the deployed servers in the datacenters. Accordingly, their IBCube designs a novel automatic port allocation scheme. Simulation results show that the IBCube design reduces the budget for the datacenter networks by 94% as well as improves the packet delay and throughput by 10.3% and 11.5%, respectively, compared to the previous partial BCube design.