This paper introduces a new adaptive method, Channel Queue Routing (CQR), for load-balanced routing on k-ary n-cube interconnection networks. CQR estimates global congestion in the network from its channel queues while relying on the implicit network backpressure to transfer congestion information to these queues. It uses this estimate to decide the directions to route in each dimension. It further load balances the network by routing in the selected directions adaptively. The only other algorithm that uses global congestion in its routing decision is the Globally Adaptive Load-Balance (GAL) algorithm introduced in [13]. GAL performs better than any other known routing algorithm on a wide variety of throughput and latency metrics. However, there are four serious issues with GAL. First, it has very high latency once it starts routing traffic non-minimally. Second, it is slow to adapt to changes in traffic. Third, it requires a complex method to achieve stability. Finally, it is complex...
Arjun Singh, William J. Dally, Amit K. Gupta, Bria