Ricerc@Sapienza

In this paper the advantages of reconfiguring the cloud and bandwidth resources in a Network Function Virtualization (NFV) architecture based on Segment Routing control/data plane is investigated when a number of maximum Service Function Chain (SFC) reconfigurations is permitted. An algorithm based on an evaluation of weight constrained shortest paths is proposed and the impact of the number of maximum permitted SFC reconfigurations on the total cloud and bandwidth cost saving is evaluated.

Network Function Virtualization is based on the virtualization of the network functions and it is a new technology allowing for a more flexible allocation of cloud and bandwidth resources. In order to employ the flexibility of the technology and to adapt its use according to the traffic variation, reconfigurations of the cloud and bandwidth resources are needed by means of both migration of the Virtual Machines executing the network functions and reconfiguration of circuits interconnecting the Virtual Machines.

The paper proposes and investigates the problem of the reconfiguration of cloud and bandwidth resources in Multi-Provider Network Function Virtualization architectures where the Cloud Infrastructures (CI) are managed by different Providers and interconnected by an elastic optical network. The resource reconfiguration is performed by taking into account the different costs charged by the Infrastructure Providers (InP) of the CIs and by exploiting the advantages of the adaptive optical modulation.