A Study on Substrate Network Synchrony Demands to Support Hybrid Synchrony Virtual Networks

Network virtualization has been proposed in the last years, and it received special attention from both networking and distributed systems communities. By offering a flexible and economic alternative for the deployment of customized networks, a wide set of applications becomes eligible to run on top of such infrastructures. However, specific applications´ requirements, such as topology, security, and resilience, pose different challenges to the network embedding problem. Among these requirements lays the one of synchrony, that some applications demand time bounds for processing and communication. In this sense, Hybrid Synchrony Virtual Networks (HSVN) has been proposed to fulfil specific synchrony requirements and better support a considerable class of distributed systems. Considering HSVNs, one of the main challenges is to minimize the need for synchronous components in the substrate network, due to their high cost. In this paper, we propose a mathematical model that aims at defining an economic synchrony configuration of the substrate network, subject to the virtual networks demands, and we analyse the physical synchronous resources regarding their properties and topology.