Distributed Weight Matching Dispatching Scheme in MSM Clos-Network Packet Switches

With the objectives of achieving high-throughput switching with the reasonable hardware and algorithm complexity, we propose a distributed weight matching dispatching (DWMD) scheme for Memory-Space-Memory(MSM) Clos-network switches. In the DWMD scheme, each input module balances request tokens among central modules, where virtual token counters are adopted to keep counting the request tokens that have been received. Each central module performs LQF(longest-queue-first)-based matching algorithm concurrently and independently. DWMD combines the basis of load balancing and iterative weight matching scheme without raising out-of-order problem and adding communication overhead. Simulation results show that DWMD can provide 100% throughput under uniform and unbalanced traffic, and higher throughput under diagonal traffic than its weight matching counterpart.