LatencySmasher: A Software-Defined Networking-Based Framework for End-to-End Latency Optimization

The centralized control capability of Software Defined Networking (SDN) presents a unique opportunity for enabling Quality of Service (QoS) routing. For delay sensitive traffic flows, a QoS mechanism requires efficiently computing path latency and minimizing controller's response time. At the core of the challenges is how to handle short term network state fluctuations in terms of congestion and latency while guaranteeing the end-to-end latency performance of networking services. In this paper, we present LatencySmasher, a systematic framework that considers active link latency measurements, efficient statistic estimate of network states, and fast adaptive path computation. We first implement LatencySmasher as an SDN controller application and then conduct extensive experimental studies on the Global Environment for Network Innovations (GENI), a real world distributed network testbed. Our performance evaluation shows that the proposed framework can find optimal end-to-end paths with minimum latency and significantly reduce the control overhead.