DFVisor: Scalable Network Virtualization for QoS Management in Cloud Computing

Increasingly cloud-based virtual networking environments are required to provide fine-grained Quality of Service (QoS) management without sacrificing scalability. However, no single approach currently can meet these requirements simultaneously. This paper introduces a layered concept that uses a common overlay mechanism to virtualize networks and enable fine-grained QoS management through resource slicing. Based on this mechanism, a fully distributed network virtualization platform called Distributed FlowVisor (DFVisor) is proposed. It uses a layered overlay to improve the network addressing space, reduce flow setup latency, and remove the single point of failure in the network - the central slice controller. Through a distributed synchronized two-level database, DFVisor incorporates a push-based flow setup and statistics collecting mechanism using a dedicated data channel to address the scalability issues caused by the current pull-based mechanism and the limited control channel bandwidth shared by both control flows and network statistics. The potential issues in DFVisor implementation and evaluation are discussed for future research.