Joint backup capacity allocation and embedding for survivable virtual networks

A key challenge in Network Virtualization is to efficiently map a virtual network (VN) on a substrate network (SN) while accounting for possible substrate failures. This is known as the Survivable Virtual Network Embedding (SVNE) problem. The state-of-the-art literature has studied the SVNE problem from infrastructure providers' (InPs) perspective, i.e., provisioning backup resources in the SN. A rather unexplored solution spectrum is to augment the VN with sufficient spare backup capacity to survive substrate failures and embed the resulting VN accordingly. Such augmentation enables InPs to offload failure recovery decisions to the VN operator, thus, providing more flexible VN management. In this paper, we study the problem of jointly optimizing spare backup capacity allocation in a VN and embedding the VN to guarantee full bandwidth in the presence of single substrate link failure. We formulate the optimal solution to the joint optimization problem as a quadratic integer program that we transform into an integer linear program. We propose a heuristic algorithm to solve larger instances of the problem. Simulation results show that our heuristic allocates ~21% extra resources compared to the optimal, while executing several orders of magnitude faster.