Dynamic virtual network restoration with optimal standby virtual router selection

Abstract

Fault-tolerance in a virtualized networking environment (VNE) requires additional efforts to provide the survivability against failures on either virtual networks (VNs) or the underlying substrate network. In this dissertation, we design a software-defined resilient VNE using a hybrid scheme of protection and restoration, where for each VN, a set of redundant virtual routers (VRs) are reserved as shared standby virtual routers (S-VRs), and any S-VR can be activated to replace a failed VR in the existed VN dynamically after the failure is identified. We first introduce a dynamic reconfiguration scheme (DRS) for node failures in a VNE, and then propose a Mixed-Integer Linear Programming (MILP) model with dual goals to optimally select S-VRs to restore all VNs while load balancing, and a heuristic algorithm based on the model is also presented. By considering a number of factors, the results showed that the proposed heuristics performance was close to the optimization model when there were sufficient standby virtual routers for each virtual network and the substrate nodes had the capability to support multiple standby virtual routers to be in service simultaneously. Finally, we present a prototyping design and implementation on the realistic virtual network testbeds (i.e., GpENI and GENI).