Differentiated QoS guarantee in optical switches for datacenters

We consider differentiated time-critical task scheduling in an N × N optical packet switch to ensure 100% throughput and meet different delay requirements among various modules of data center networks (DCNs). Existing algorithms assume that each input-output connection has the same delay bound, which cannot satisfy users´ differentiated QoS requirements. To make up this deficiency, we propose a new scheduling scheme to meet the delay requirements in a best-effort manner. Moreover, a speedup is considered to compensate for both the reconfiguration overhead and the unavoidable slots wastage in the switch fabric. With traffic matrix and delay constraint matrix given, this paper proposes an algorithm SDF (Strict Delay First) to realize the packet switching, while minimizing the required speedup. The performance of our scheme is verified by extensive numerical simulations.