Backlog Aware Scheduling for Ingress Memories in High-Radix, Single-Stage Switches

Previous work has proposed the Dynamic Switch Buffer Management (DSBM) scheme, a promising approach for improving the scalability of switch ingress memories. In this paper, we extend these results by adding increased backlog awareness into the latter. In particular, we propose using a novel combination of two backlog-aware algorithms: BA-DSBM to map incoming packets to the switch\´s ingress buffers and the Backlog-Aware Wrapped Wavefront Arbiter (BA-WWFA) to set the configuration of the switch fabric. We then simulate these algorithms under a variety of load intensities and types. These simulations suggest that adding backlog-awareness into the DSBM scheme leads to significant performance enhancements, particularly as the switch is "stressed" by asymmetric or heavy loading. Our algorithms, therefore, mitigate some of the design tradeoffs made in this novel, highly-scalable switch design.