Diamond: An Improved Fat-tree Architecture for Large-scale Data Centers

With the widespread deployment of cloud services, data center networks are developing toward large-scale, multipath networks. To support the new trend, some novel network architectures have been proposed, and Fat-tree is one of the most promising architecture and gets a lot of attention because it has good performance on aggregate bandwidth with a simple topology. This paper presents Diamond, an improved Fat-tree architecture for large-scale data centers. Diamond replaces all the aggregation switches of Fat-tree with edge switches and connects directly edge switches to core switches. By this alteration, the average route path and End-to-End (ETE) delay in Diamond are 10% less than that in Fat-tree. We design FAR, a simple and high-efficient routing method for Diamond. In FAR, each switch requires only hundreds of route entries to support a large-scale network with tens of thousands servers, and to build FAR routing tables, switches exchange very few messages. Diamond and its FAR routing are verified through OPNET simulations. 