Multidimensional Resource Allocation in NFV Cloud

Network Function Virtualization (NFV) is a new networking paradigm in which network functionality is implemented on top of virtual infrastructure deployed over COTS servers. One of the main motivations for the shift of telco operators into this paradigm is cost reduction, thus the efficient use of resources is an important challenge in this area. This problem is complex since the term ``resources'' covers different orthogonal aspects, such as servers CPU, storage (or disk) usage, and network capacity. In this paper we study the placement of the VMs (Virtual Machines) that implement the network functions over the physical infrastructure, trying to understand what makes a placement scheme better than others in the overall utilization of the various resources. We show that the multidimensional case is inherently different from the single dimension case, and develop novel placement heuristics to address the specific challenges. We then show, by extensive evaluation over real data, that operators can significantly improve their resource utilization by selecting the most appropriate placement policy, according to their system specifications and the deployed network functions.