Flipping the Data Center Network: Increasing East-West Capacity Using Existing Hardware

In today's datacenters, there is an increasing demand for more network traffic capacity. The majority of the increase in traffic is internal to the datacenter, i.e., it flows between different servers within the datacenter. This category of traffic is often referred to as east-west traffic and traditional hierarchical architectures are not well equipped to handle this type of traffic. Instead, they are better suited for the north-southbound traffic between hosts and the Internet. One suggested solution for this capacity problem is to adopt a folded CLOS topology, also known as spine-leaf, which often relies on software defined network (SDN) controllers to manage traffic. This paper shows that it is possible to implement a spine-leaf network using commodity-ofthe-shelf switches and thus improve the east-west traffic capacity. This can be obtained using low complexity configuration and edgerouting for load balancing, eliminating the need for a centralized SDN controller.