Profit-aware placement of multi-flavoured VNF chains

Network Function Virtualization (NFV) is a promising approach for network operators to cope with the increasing demand for network services in a flexible and cost-efficient way. How to place Virtualized Network Function (VNF) chains across the network infrastructure to achieve providers' goals is a relevant research problem. Several emerging aspects, such as possible resource shortage at edge locations and the demand for accelerated infrastructural resources for high-performance deployments, make this problem even more challenging. In such cases, downgrading a service request to an alternative flavour (with less stringent resource requirements and/or fewer offered features) might help increasing the acceptance rate and, to a certain extent, the network service provider's profit. In this work we formalize the problem of placing network services specified as multi-flavoured VNF chains and present an Integer Linear Programming (ILP) approach for optimally solving it. Simulation results demonstrate the feasibility and potential benefit of the proposed approach, both in online and offline placement scenarios, with an improvement in profit of up to 16% and 18%, respectively, with respect to the case where requests are specified in a single flavour.