Optimisation Models for Robust and Survivable Network Slice Design: A Comparative Analysis

Techniques like Network Functions Virtualisation and Software Defined Networking provide a new dimension of flexibility in the deployment, operation and maintenance of telecommunication networks. They also enable the realisation of multiple virtual networks (multi-tenancy) on a common substrate network infrastructure. Provisioning such virtual networks requires efficient resource allocation mechanisms so that the utility of the substrate infrastructure provider can be maximised. In this work, we first outline a mathematical model for the general network slice design problem and extend it to cope with traffic uncertainties. We employ the Γ-robust uncertainty set \cite{bertsimas:03}, \cite{bertsimas:04} to model the uncertainties in the traffic demands. Furthermore, we add survivability aspects to our model by protecting the network slice against single substrate network element (node/link) failures. Finally, both survivability and traffic robustness approaches are considered simultaneously and we present two different optimisation models. A performance evaluation is carried out comparing the different robust and survivable models with their non-robust non-survivable counterpart using network topology examples from SNDlib.