The interleaved matching switch architecture

Operators need routers to provide service guarantees such as guaranteed flow rates and fairness among flows, so as to support traffic engineering and real-time traffic. However, current centralized input-queued router architectures cannot scale to fast line rates while providing these service guarantees. On the other hand, while load-balanced switch architectures that rely on two identical stages of fixed-configuration switches appear to be an effective way to scale Internet routers to very high capacities, there is currently no practical and scalable solution for providing service guarantees in these architectures. In this paper, we introduce the interleaved matching switch (IMS) architecture, which relies on a novel approach to provide service guarantees using load-balanced switches. The approach is based on emulating a Birkhoff-von Neumann switch with a load-balanced switch architecture and is applicable to any known admissible traffic. We show that service guarantees, 100% throughput, and packet ordering can be achieved with O(1) online complexity. In cases where fixed frame sizes are applicable, we also present an efficient offline frame-based decomposition method. More generally, we show that the IMS architecture can be used to emulate any input queued or combined input-output queued switch, leveraging a large body of known results for ensuring stability.