CaRA : Congestion-aware Routing Algorithm for Data Center Network

The data center networks (DCN) leverage redundant physical links to overcome the bottleneck of traditional tree topology and achieve high bisection bandwidth and goodput for cloud computing platform, so how to use these redundancy links efficiently becomes the key factor for routing designer. This paper analyzes the large flow collision in modular data center network and propose simple experiments to validate the performance decreasing in the aggregated throughput. And then, a recursive congestion-aware routing algorithm (called CaRA) is proposed for decreasing flow collision. We simulate the CaRA with NS-2 simulator, and the results show that CaRA can improve one-to-one packet forward throughput and all-to-all throughput most time. The peak throughput values in these two situations are 50% and 20% respectively.