Quality of service using careful overbooking for optimal virtual network resource allocation

Virtual network embedding which maps the virtual networks to a substrate network is important for problems in the network virtualization. The conventional mapping methods only provide the exclusive service that allocates the whole bandwidth with a full availability to requests. This kind of service is not flexible enough to serve the variety of demands. With these observations, this paper has proposed to analyze the application of careful overbooking concept that uses flexible levels of availability to provide Service Level Agreements (SLA) to users. Based on this framework, virtual network subscribers are provided with a service that is most suitable with their tolerability to utilize the soft-guaranteed bandwidths. This helps to save the cost of subscribers and to increase the profitability of the provider. Furthermore, to route resultant traffics through a substrate network, we have applied a Mixed-Integer Programming formulation to minimize the virtual network cost. The reported numerical results demonstrate that our method significantly reduces the cost of operating virtual network while guaranteeing the required carefully overbooked quality of service.