Design of reliable virtual infrastructure with resource sharing

Network virtualization technology allows multiple virtual infrastructures (VIs) or virtual networks customized to suit user requirements on a shared substrate network without the need for much additional infrastructure. However, in such a scenario, even a single failure in the substrate can cause large disruptions as it will affect all the VIs mapped onto it. Thus, the problem of guaranteeing survivability and reliability of VI is important, and even more complex than in single layer networks. In this paper, we study the reliable VI mapping problem that enables efficient resource sharing by using the cross sharing scheme that reuses the primary bandwidth for backup VI links. In addition, we also study the sharing of backup resources across multiple different VI requests.We first formulate the reliable VI mapping problem as a mixed integer programming (MIP) problem to minimize the VI mapping cost. We then present our reliable VI mapping (RVIM) algorithm for efficient bandwidth sharing using the cross and backup sharing schemes. Finally, we present the VI combination (ComVI) algorithm to generate shared backup VI nodes and links for multiple VI requests in a cost efficient manner. Through simulation we show that our RVIM algorithm can reduce the mapping costs when compared to other VI mapping algorithms, and backup resource sharing using ComVI can reduce the total mapping cost efficiently.