A failure avoidance oriented approach for virtual network reliability enhancement

Network virtualization allows the co-existing of logical networks (virtual networks) on physical network (substrate networks). Virtual Network (VN) reliability is a critical problem for end-users and service providers. It aims to ensure service continuity even upon failure. As more and more VNs are created over substrate networks (SN), the failure of a single SN component may lead to the failure of many VNs. Thus, the VN reliability issue is becoming more and more critical. VN reliability can be enhanced in two ways: (1) by failure recovery (post-failure) with protection and/or restoration methods; (2) by failure avoidance with the selection of most reliable components at the network topology setting phase. Traditional virtual network embedding (VNE) methods have mainly focused on bandwidth optimization. In this paper, we focus on the reliability issue. We propose VNE methods which take into account the failure probability of SN components with a failure-avoidance approach, in order to minimize the VN failure probability. Our heuristics are based on the use of Steiner Minimal Tree (SMT). Simulations results confirm that our heuristics provide better reliability against traditional VNE with bandwidth as sole target, and, in case of failure of a SN component, reduce the number of affected VNs.