The Power of Alternatives in Network Embedding

In the virtual network embedding problem, the goal is to map (embed) a set of virtual network instances to a given physical network substrate at minimal cost, while respecting the capacity constraints of the physical network. This NP-hard problem is fundamental to network virtualization, embodying essential properties of resource allocation problems faced by service providers in the edge-to-cloud spectrum. Due to its centrality, this problem and its variants have been extensively studied and remain in the focus of the research community. In this paper, we present a new variant, the virtual network embedding with alternatives problem (VNEAP). This new problem captures the power of a common network virtualization practice, in which virtual network topologies are malleable—embedding of a given virtual network instance can be performed using any of the alternatives from a given set of topology alternatives. We provide two efficient heuristics for VNEAP and show that having multiple virtual network alternatives for the same application is superior to the best results known for the classic formulation. We conclude that capturing the problem domain via VNEAP can facilitate more efficient network virtualization solutions.