The kDRR Scheduling Algorithms for Multi-server Packet Switches

Tremendous increase of Internet traffic demands high speed, large capacity IP switch routers. The introduction of multi-server switch architectures not only makes it possible to scale to larger switch capacities, but also imposes special requirements on scheduling algorithms running in the central scheduler. In this paper, we model the multi-server switch scheduling problem as a maximum bipartite K-matching problem. We generalize iSLIP and DRR to multi-server switch architectures and propose two distributed scheduling algorithms kDRR RGA and kDRR RG for finding maximal K-matchings. Through simulations, we show that both algorithms achieve comparable performance with high throughput under uniform traffic. Using programmable k-selectors, kDRR RGA and kDRR RG are ready to be implemented at high speed.