The Concurrent Matching Switch Architecture

Abstract

Network operators need high-capacity router architectures that can offer scalability, provide throughput guarantees, and maintain packet ordering. However, current centralized crossbar-based architectures cannot scale to fast line rates and high port counts. On the other hand, while load-balanced switch architectures that rely on two identical stages of fixed configuration meshes appear to be an effective way to scale Internet routers to very high capacities, they incur a large worst-case packet reordering that is at best quadratic to the switch size. In this paper, we introduce the concurrent matching switch (CMS) architecture, which also uses two identical stages of fixed configuration meshes with the same scalability properties as current load-balanced routers. However, by adopting a novel contention-resolution architecture that is scalable and distributed, the CMS architecture enforces packet ordering throughout the switch. Using the CMS architecture, we show that scalability, 100% throughput, packet ordering, and O(1) amortized time complexity with sequential hardware per linecard can all be achieved. We further demonstrate a delay analysis for the CMS architecture.