Flattened Clos - Designing High-performance Deadlock-free Expander Data Center Networks Using Graph Contraction

Explore a groundbreaking approach to designing high-performance, deadlock-free expander data center networks in this 17-minute conference talk from NSDI '23. Delve into the innovative Flattened Clos (FC) topology and routing co-design method, which addresses the challenges of cost-efficient network expansion while eliminating Cyclic Buffer Dependency (CBD) in PFC-enabled RoCE networks. Learn how FC's three-step design process logically divides ToR switches, generates virtual up-down paths, and flattens the network using graph contraction. Discover the rigorous proof of FC's deadlock-free property and its impressive performance improvements, including a 50% reduction in average hop count and 2-10x increase in network throughput compared to existing expander graph solutions. Gain insights into FC's advantages over traditional Clos networks, with throughput increases of 1.1-2x under various traffic patterns. Presented by researchers from Shanghai Jiao Tong University and the Chinese Academy of Sciences, this talk offers valuable knowledge for network engineers and researchers seeking to optimize data center network design and performance.