Towards load-balanced VNF assignment in geo-distributed NFV Infrastructure

Network functions virtualization (NFV) is increasingly adopted by telecommunications (telecos) service providers for cost savings and flexible management. However, deploying virtual network functions (VNFs) in geo-distributed central offices (COs) is not straightforward. Unlike most existing centralized schemes in clouds, VNFs of a service chain usually need to be deployed in multiple COs due to limited resource capacity and uneven setup cost at various locations. To ensure the Quality of Service of service chains, a key problem for service providers is to determine where a VNF should go, in order to achieve cost-efficiency and load balancing of both computing and bandwidth resources, across all selected COs. To this end, we present a framework of CO Selection (CS) and VNF Assignment (VA) for distributed deployment of NFV. Specifically, we first select a set of COs that minimizes the communication cost among the selected COs. Then, we employ a shadow-routing based approach, which minimizes the maximum of appropriately defined CO utilizations, to jointly solve the VNF-CO and VNF-server assignment problem. Simulations demonstrate the effectiveness of CS algorithm, and asymptotic optimality, scalability and high adaptivity of the VNF assignment approach.