Cost analysis of initial deployment strategies for virtualized mobile core network functions

Abstract

A virtualized network infrastructure is composed of multiple virtualized network functions (VNF) interconnected by well defined interfaces, and thus forming a VNF-graph. The initial deployment of such a VNF-graph inside a data center (DC) is a complex task with multidimensional aspects compared to deploying a single VNF that may represent a single network function. The problem space becomes more complex when each VNF is further decomposed into multiple VNF components (VNFC), where each VNFC embodies a subset of network functions attributed to the respective VNF. The challenge is to ensure that the deployment strategy meets the intra-functional constraints between the multiple VNFCs constituting the VNF-graph while ensuring service, performance and operational integrity, and also ensures optimal utilization of the underlying resources of the DC infrastructure (DCI). In this article we analyze the cost incurred by two "constraint-based heuristically applied" initial VNF/VNFC deployment strategies with reference to a virtualized mobile network infrastructure providing EPCaaS (evolved packet core as a service) while taking into consideration functional and administrative constraints. The cost of deployment is measured in terms of the utilization of DC infrastructure resources such as compute and networking. We also present the discussion in view of the ETSI NFV MANO framework, undergoing standardization, that is responsible for management and orchestration of NFV systems including VNF deployment.