Zhejiang Sci-Tech University
The feedback-based two-stage switch does not require a central scheduler and can provide close to 100% throughput. But the number of cross-points required for the two stages of switch fabric is 2N2, and the average packet delay performance (even under light traffic load) is on the order of O(N) slots, where N is the switch size. To improve the performance of feedback based two-stage switch when N is large, the authors adopt the Clos network for constructing a large switch from a set of smaller feedback-based switch modules. They call it a Clos-feedback switch. The potential problem of packet mis-sequencing is solved by using application-flow based load balancing.